,

Dependencies:   mbed

Files at this revision

API Documentation at this revision

Comitter:
jjeong
Date:
Sat Dec 03 08:21:37 2022 +0000
Commit message:
controller for quadrotor with RF24 driver;

Changed in this revision

RF24.cpp Show annotated file Show diff for this revision Revisions of this file
RF24.h Show annotated file Show diff for this revision Revisions of this file
RF24_config.h Show annotated file Show diff for this revision Revisions of this file
main.cpp Show annotated file Show diff for this revision Revisions of this file
mbed.bld Show annotated file Show diff for this revision Revisions of this file
mbed_config.h Show annotated file Show diff for this revision Revisions of this file
nRF24L01.h Show annotated file Show diff for this revision Revisions of this file
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/RF24.cpp	Sat Dec 03 08:21:37 2022 +0000
@@ -0,0 +1,1316 @@
+/*
+ Copyright (C) 2011 J. Coliz <maniacbug@ymail.com>
+ 
+ This program is free software; you can redistribute it and/or
+ modify it under the terms of the GNU General Public License
+ version 2 as published by the Free Software Foundation.
+ */
+ 
+/*
+ * Mbed support added by Akash Vibhute <akash.roboticist@gmail.com>
+ * Porting completed on Nov/05/2015
+ *
+ * Updated 1: Synced with TMRh20's RF24 library on Nov/04/2015 from https://github.com/TMRh20
+ * Updated 2: Synced with TMRh20's RF24 library on Apr/18/2015 from https://github.com/TMRh20
+ *
+ */
+ 
+#include "nRF24L01.h"
+#include "RF24_config.h"
+#include "RF24.h"
+ 
+/****************************************************************************/
+ 
+void RF24::csn(bool mode)
+{
+ 
+    csn_pin = mode;
+ 
+ 
+}
+ 
+/****************************************************************************/
+ 
+void RF24::ce(bool level)
+{
+  ce_pin = level;
+  
+}
+ 
+/****************************************************************************/
+ 
+  inline void RF24::beginTransaction() {
+ 
+  
+    csn(LOW);
+  }
+ 
+/****************************************************************************/
+ 
+  inline void RF24::endTransaction() {
+    csn(HIGH);
+ 
+    
+    
+  }
+ 
+/****************************************************************************/
+ 
+uint8_t RF24::read_register(uint8_t reg, uint8_t* buf, uint8_t len)
+{
+  uint8_t status;
+ 
+  
+ 
+  beginTransaction();
+  status = spi.write( R_REGISTER | ( REGISTER_MASK & reg ) );
+  while ( len-- ){
+    *buf++ = spi.write(0xff);
+  }
+  endTransaction();
+ 
+ 
+ 
+  return status;
+}
+ 
+/****************************************************************************/
+ 
+uint8_t RF24::read_register(uint8_t reg)
+{
+  uint8_t result;
+  
+ 
+  beginTransaction();
+  spi.write( R_REGISTER | ( REGISTER_MASK & reg ) );
+  result = spi.write(0xff);
+  endTransaction();
+ 
+ 
+ 
+  return result;
+}
+ 
+/****************************************************************************/
+ 
+uint8_t RF24::write_register(uint8_t reg, const uint8_t* buf, uint8_t len)
+{
+  uint8_t status;
+ 
+ 
+  beginTransaction();
+  status = spi.write( W_REGISTER | ( REGISTER_MASK & reg ) );
+  while ( len-- )
+    spi.write(*buf++);
+  endTransaction();
+ 
+  
+  
+  return status;
+}
+ 
+/****************************************************************************/
+ 
+uint8_t RF24::write_register(uint8_t reg, uint8_t value)
+{
+  uint8_t status;
+ 
+  IF_SERIAL_DEBUG(printf_P(PSTR("write_register(%02x,%02x)\r\n"),reg,value));
+ 
+  
+  beginTransaction();
+  status = spi.write( W_REGISTER | ( REGISTER_MASK & reg ) );
+  spi.write(value);
+  endTransaction();
+ 
+  
+ 
+  return status;
+}
+ 
+/****************************************************************************/
+ 
+uint8_t RF24::write_payload(const void* buf, uint8_t data_len, const uint8_t writeType)
+{
+  uint8_t status;
+  const uint8_t* current = reinterpret_cast<const uint8_t*>(buf);
+ 
+   data_len = rf24_min(data_len, payload_size);
+   uint8_t blank_len = dynamic_payloads_enabled ? 0 : payload_size - data_len;
+  
+  //printf("[Writing %u bytes %u blanks]",data_len,blank_len);
+  IF_SERIAL_DEBUG( printf("[Writing %u bytes %u blanks]\n",data_len,blank_len); );
+  
+ 
+  beginTransaction();
+  status = spi.write( writeType );
+  while ( data_len-- ) {
+    spi.write(*current++);
+  }
+  while ( blank_len-- ) {
+    spi.write(0);
+  }  
+  endTransaction();
+ 
+  
+ 
+  return status;
+}
+ 
+/****************************************************************************/
+ 
+uint8_t RF24::read_payload(void* buf, uint8_t data_len)
+{
+  uint8_t status;
+  uint8_t* current = reinterpret_cast<uint8_t*>(buf);
+ 
+  if(data_len > payload_size) data_len = payload_size;
+  uint8_t blank_len = dynamic_payloads_enabled ? 0 : payload_size - data_len;
+  
+  //printf("[Reading %u bytes %u blanks]",data_len,blank_len);
+ 
+  IF_SERIAL_DEBUG( printf("[Reading %u bytes %u blanks]\n",data_len,blank_len); );
+  
+  
+ 
+  beginTransaction();
+  status = spi.write( R_RX_PAYLOAD );
+  while ( data_len-- ) {
+    *current++ = spi.write(0xFF);
+  }
+  while ( blank_len-- ) {
+    spi.write(0xff);
+  }
+  endTransaction();
+ 
+  
+ 
+  return status;
+}
+ 
+/****************************************************************************/
+ 
+uint8_t RF24::flush_rx(void)
+{
+  return spiTrans( FLUSH_RX );
+}
+ 
+/****************************************************************************/
+ 
+uint8_t RF24::flush_tx(void)
+{
+  return spiTrans( FLUSH_TX );
+}
+ 
+/****************************************************************************/
+ 
+uint8_t RF24::spiTrans(uint8_t cmd){
+ 
+  uint8_t status;
+  
+  beginTransaction();
+  status = spi.write( cmd );
+  endTransaction();
+  
+  return status;
+}
+ 
+/****************************************************************************/
+ 
+uint8_t RF24::get_status(void)
+{
+  return spiTrans(NOP);
+}
+ 
+/****************************************************************************/
+#if !defined (MINIMAL)
+void RF24::print_status(uint8_t status)
+{
+  printf_P(PSTR("STATUS\t\t = 0x%02x RX_DR=%x TX_DS=%x MAX_RT=%x RX_P_NO=%x TX_FULL=%x\r\n"),
+           status,
+           (status & _BV(RX_DR))?1:0,
+           (status & _BV(TX_DS))?1:0,
+           (status & _BV(MAX_RT))?1:0,
+           ((status >> RX_P_NO) & 0b111),
+           (status & _BV(TX_FULL))?1:0
+          );
+}
+ 
+/****************************************************************************/
+ 
+void RF24::print_observe_tx(uint8_t value)
+{
+  printf_P(PSTR("OBSERVE_TX=%02x: POLS_CNT=%x ARC_CNT=%x\r\n"),
+           value,
+           (value >> PLOS_CNT) & 0b1111,
+           (value >> ARC_CNT) & 0b1111
+          );
+}
+ 
+/****************************************************************************/
+ 
+void RF24::print_byte_register(const char* name, uint8_t reg, uint8_t qty)
+{
+  //char extra_tab = strlen_P(name) < 8 ? '\t' : 0;
+  //printf_P(PSTR(PRIPSTR"\t%c ="),name,extra_tab);
+  
+  
+  
+    printf_P(PSTR(PRIPSTR"\t ="),name);
+  
+  while (qty--)
+    printf_P(PSTR(" 0x%02x"),read_register(reg++));
+  printf_P(PSTR("\r\n"));
+}
+ 
+/****************************************************************************/
+ 
+void RF24::print_address_register(const char* name, uint8_t reg, uint8_t qty)
+{
+ 
+  
+  
+  
+    printf_P(PSTR(PRIPSTR"\t ="),name);
+  
+  while (qty--)
+  {
+    uint8_t buffer[addr_width];
+    read_register(reg++,buffer,sizeof buffer);
+ 
+    printf_P(PSTR(" 0x"));
+    uint8_t* bufptr = buffer + sizeof buffer;
+    while( --bufptr >= buffer )
+      printf_P(PSTR("%02x"),*bufptr);
+  }
+ 
+  printf_P(PSTR("\r\n"));
+}
+#endif
+/****************************************************************************/
+RF24::RF24(PinName mosi, PinName miso, PinName sck, PinName _cepin, PinName _csnpin):
+  spi(mosi, miso, sck), ce_pin(_cepin), csn_pin(_csnpin), p_variant(true),
+  payload_size(32), dynamic_payloads_enabled(false), addr_width(5)
+{
+  pipe0_reading_address[0]=0;
+  
+  //spi.frequency(10000000/5);     // 2Mbit, 1/5th the maximum transfer rate for the spi bus
+  spi.frequency(10000000/5);
+  //spi.format(8,0);               // 8-bit, ClockPhase = 0, ClockPolarity = 0
+  spi.format(8,0);               
+  wait_ms(10);
+}
+ 
+ 
+ 
+ 
+ 
+ 
+ 
+ 
+/****************************************************************************/
+ 
+void RF24::setChannel(uint8_t channel)
+{
+  const uint8_t max_channel = 125;
+  write_register(RF_CH,rf24_min(channel,max_channel));
+}
+ 
+uint8_t RF24::getChannel()
+{
+  
+  return read_register(RF_CH);
+}
+/****************************************************************************/
+ 
+void RF24::setPayloadSize(uint8_t size)
+{
+  payload_size = rf24_min(size,32);
+}
+ 
+/****************************************************************************/
+ 
+uint8_t RF24::getPayloadSize(void)
+{
+  return payload_size;
+}
+ 
+/****************************************************************************/
+ 
+#if !defined (MINIMAL)
+ 
+static const char rf24_datarate_e_str_0[] PROGMEM = "1MBPS";
+static const char rf24_datarate_e_str_1[] PROGMEM = "2MBPS";
+static const char rf24_datarate_e_str_2[] PROGMEM = "250KBPS";
+static const char * const rf24_datarate_e_str_P[] PROGMEM = {
+  rf24_datarate_e_str_0,
+  rf24_datarate_e_str_1,
+  rf24_datarate_e_str_2,
+};
+static const char rf24_model_e_str_0[] PROGMEM = "nRF24L01";
+static const char rf24_model_e_str_1[] PROGMEM = "nRF24L01+";
+static const char * const rf24_model_e_str_P[] PROGMEM = {
+  rf24_model_e_str_0,
+  rf24_model_e_str_1,
+};
+static const char rf24_crclength_e_str_0[] PROGMEM = "Disabled";
+static const char rf24_crclength_e_str_1[] PROGMEM = "8 bits";
+static const char rf24_crclength_e_str_2[] PROGMEM = "16 bits" ;
+static const char * const rf24_crclength_e_str_P[] PROGMEM = {
+  rf24_crclength_e_str_0,
+  rf24_crclength_e_str_1,
+  rf24_crclength_e_str_2,
+};
+static const char rf24_pa_dbm_e_str_0[] PROGMEM = "PA_MIN";
+static const char rf24_pa_dbm_e_str_1[] PROGMEM = "PA_LOW";
+static const char rf24_pa_dbm_e_str_2[] PROGMEM = "PA_HIGH";
+static const char rf24_pa_dbm_e_str_3[] PROGMEM = "PA_MAX";
+static const char * const rf24_pa_dbm_e_str_P[] PROGMEM = {
+  rf24_pa_dbm_e_str_0,
+  rf24_pa_dbm_e_str_1,
+  rf24_pa_dbm_e_str_2,
+  rf24_pa_dbm_e_str_3,
+};
+ 
+ 
+ 
+ 
+ 
+ 
+ 
+ 
+ 
+ 
+ 
+ 
+ 
+ 
+void RF24::printDetails(void)
+{
+ 
+ 
+  print_status(get_status());
+ 
+  print_address_register(PSTR("RX_ADDR_P0-1"),RX_ADDR_P0,2);
+  print_byte_register(PSTR("RX_ADDR_P2-5"),RX_ADDR_P2,4);
+  print_address_register(PSTR("TX_ADDR\t"),TX_ADDR);
+ 
+  print_byte_register(PSTR("RX_PW_P0-6"),RX_PW_P0,6);
+  print_byte_register(PSTR("EN_AA\t"),EN_AA);
+  print_byte_register(PSTR("EN_RXADDR"),EN_RXADDR);
+  print_byte_register(PSTR("RF_CH\t"),RF_CH);
+  print_byte_register(PSTR("RF_SETUP"),RF_SETUP);
+  print_byte_register(PSTR("CONFIG\t"),NRF_CONFIG);
+  print_byte_register(PSTR("DYNPD/FEATURE"),DYNPD,2);
+ 
+  printf_P(PSTR("Data Rate\t = " PRIPSTR "\r\n"),pgm_read_word(&rf24_datarate_e_str_P[getDataRate()]));
+  printf_P(PSTR("Model\t\t = " PRIPSTR "\r\n"),pgm_read_word(&rf24_model_e_str_P[isPVariant()]));
+  printf_P(PSTR("CRC Length\t = " PRIPSTR "\r\n"),pgm_read_word(&rf24_crclength_e_str_P[getCRCLength()]));
+  printf_P(PSTR("PA Power\t = " PRIPSTR "\r\n"),  pgm_read_word(&rf24_pa_dbm_e_str_P[getPALevel()]));
+ 
+}
+ 
+#endif
+/****************************************************************************/
+ 
+bool RF24::begin(void)
+{
+ 
+  uint8_t setup=0;
+ 
+    mainTimer.start();
+  
+    ce(LOW);
+    csn(HIGH);
+ 
+    wait_ms(100);
+ 
+ 
+ 
+ 
+  // Must allow the radio time to settle else configuration bits will not necessarily stick.
+  // This is actually only required following power up but some settling time also appears to
+  // be required after resets too. For full coverage, we'll always assume the worst.
+  // Enabling 16b CRC is by far the most obvious case if the wrong timing is used - or skipped.
+  // Technically we require 4.5ms + 14us as a worst case. We'll just call it 5ms for good measure.
+  // WARNING: Delay is based on P-variant whereby non-P *may* require different timing.
+  wait_ms( 5 ) ;
+ 
+  // Reset NRF_CONFIG and enable 16-bit CRC.
+  write_register( NRF_CONFIG, 0b00001100 ) ;
+ 
+  // Set 1500uS (minimum for 32B payload in ESB@250KBPS) timeouts, to make testing a little easier
+  // WARNING: If this is ever lowered, either 250KBS mode with AA is broken or maximum packet
+  // sizes must never be used. See documentation for a more complete explanation.
+  setRetries(5,15);
+ 
+  // Reset value is MAX
+  //setPALevel( RF24_PA_MAX ) ;
+ 
+  // check for connected module and if this is a p nRF24l01 variant
+  //
+  if( setDataRate( RF24_250KBPS ) )
+  {
+    p_variant = true ;
+  }
+  setup = read_register(RF_SETUP);
+  /*if( setup == 0b00001110 )     // register default for nRF24L01P
+  {
+    p_variant = true ;
+  }*/
+  
+  // Then set the data rate to the slowest (and most reliable) speed supported by all
+  // hardware.
+  //setDataRate( RF24_1MBPS ) ;
+  setDataRate( RF24_1MBPS ) ;
+ 
+  // Initialize CRC and request 2-byte (16bit) CRC
+  setCRCLength( RF24_CRC_16 ) ;
+ 
+  // Disable dynamic payloads, to match dynamic_payloads_enabled setting - Reset value is 0
+  toggle_features();
+  write_register(FEATURE,0 );
+  write_register(DYNPD,0);
+ 
+  // Reset current status
+  // Notice reset and flush is the last thing we do
+  write_register(NRF_STATUS,_BV(RX_DR) | _BV(TX_DS) | _BV(MAX_RT) );
+ 
+  // Set up default configuration.  Callers can always change it later.
+  // This channel should be universally safe and not bleed over into adjacent
+  // spectrum.
+  setChannel(76);
+ 
+  // Flush buffers
+  flush_rx();
+  flush_tx();
+ 
+  powerUp(); //Power up by default when begin() is called
+ 
+  // Enable PTX, do not write CE high so radio will remain in standby I mode ( 130us max to transition to RX or TX instead of 1500us from powerUp )
+  // PTX should use only 22uA of power
+  write_register(NRF_CONFIG, ( read_register(NRF_CONFIG) ) & ~_BV(PRIM_RX) );
+    printDetails();
+  // if setup is 0 or ff then there was no response from module
+  return ( setup != 0 && setup != 0xff );
+}
+ 
+/****************************************************************************/
+ 
+void RF24::startListening(void)
+{
+ 
+ 
+ 
+  write_register(NRF_CONFIG, read_register(NRF_CONFIG) | _BV(PRIM_RX));
+  write_register(NRF_STATUS, _BV(RX_DR) | _BV(TX_DS) | _BV(MAX_RT) );
+  ce(HIGH);
+  // Restore the pipe0 adddress, if exists
+  if (pipe0_reading_address[0] > 0){
+    write_register(RX_ADDR_P0, pipe0_reading_address, addr_width);  
+  }else{
+    closeReadingPipe(0);
+  }
+ 
+  // Flush buffers
+  //flush_rx();
+  if(read_register(FEATURE) & _BV(EN_ACK_PAY)){
+    flush_tx();
+  }
+ 
+  // Go!
+  //delayMicroseconds(100);
+}
+ 
+/****************************************************************************/
+static const uint8_t child_pipe_enable[] PROGMEM =
+{
+  ERX_P0, ERX_P1, ERX_P2, ERX_P3, ERX_P4, ERX_P5
+};
+ 
+void RF24::stopListening(void)
+{  
+  ce(LOW);
+ 
+  wait_us(txRxDelay);
+  
+  if(read_register(FEATURE) & _BV(EN_ACK_PAY)){
+    wait_us(txRxDelay); //200
+    flush_tx();
+  }
+  //flush_rx();
+  write_register(NRF_CONFIG, ( read_register(NRF_CONFIG) ) & ~_BV(PRIM_RX) );
+ 
+  
+  write_register(EN_RXADDR,read_register(EN_RXADDR) | _BV(pgm_read_byte(&child_pipe_enable[0]))); // Enable RX on pipe0
+  
+  //delayMicroseconds(100);
+ 
+}
+ 
+/****************************************************************************/
+ 
+void RF24::powerDown(void)
+{
+  ce(LOW); // Guarantee CE is low on powerDown
+  write_register(NRF_CONFIG,read_register(NRF_CONFIG) & ~_BV(PWR_UP));
+}
+ 
+/****************************************************************************/
+ 
+//Power up now. Radio will not power down unless instructed by MCU for config changes etc.
+void RF24::powerUp(void)
+{
+   uint8_t cfg = read_register(NRF_CONFIG);
+ 
+   // if not powered up then power up and wait for the radio to initialize
+   if (!(cfg & _BV(PWR_UP))){
+      write_register(NRF_CONFIG, cfg | _BV(PWR_UP));
+ 
+      // For nRF24L01+ to go from power down mode to TX or RX mode it must first pass through stand-by mode.
+      // There must be a delay of Tpd2stby (see Table 16.) after the nRF24L01+ leaves power down mode before
+      // the CEis set high. - Tpd2stby can be up to 5ms per the 1.0 datasheet
+      wait_ms(5);
+   }
+}
+ 
+/******************************************************************/
+#if defined (FAILURE_HANDLING) || defined (RF24_LINUX)
+void RF24::errNotify(){
+    #if defined (SERIAL_DEBUG) || defined (RF24_LINUX)
+      printf_P(PSTR("RF24 HARDWARE FAIL: Radio not responding, verify pin connections, wiring, etc.\r\n"));
+    #endif
+    #if defined (FAILURE_HANDLING)
+    failureDetected = 1;
+    #else
+    wait_ms(5000);
+    #endif
+}
+#endif
+/******************************************************************/
+ 
+//Similar to the previous write, clears the interrupt flags
+bool RF24::write( const void* buf, uint8_t len, const bool multicast )
+{
+    //Start Writing
+    startFastWrite(buf,len,multicast);
+ 
+    //Wait until complete or failed
+    #if defined (FAILURE_HANDLING) || defined (RF24_LINUX)
+        uint32_t timer = mainTimer.read_ms();
+    #endif 
+    
+    while( ! ( get_status()  & ( _BV(TX_DS) | _BV(MAX_RT) ))) { 
+        #if defined (FAILURE_HANDLING) || defined (RF24_LINUX)
+            if(mainTimer.read_ms() - timer > 95){           
+                errNotify();
+                #if defined (FAILURE_HANDLING)
+                  return 0;     
+                #else
+                  wait_ms(100);
+                #endif
+            }
+        #endif
+    }
+    
+    ce(LOW);
+ 
+    uint8_t status = write_register(NRF_STATUS,_BV(RX_DR) | _BV(TX_DS) | _BV(MAX_RT) );
+ 
+  //Max retries exceeded
+  if( status & _BV(MAX_RT)){
+    flush_tx(); //Only going to be 1 packet int the FIFO at a time using this method, so just flush
+    return 0;
+  }
+    //TX OK 1 or 0
+  return 1;
+}
+ 
+bool RF24::write( const void* buf, uint8_t len ){
+    return write(buf,len,0);
+}
+/****************************************************************************/
+ 
+//For general use, the interrupt flags are not important to clear
+bool RF24::writeBlocking( const void* buf, uint8_t len, uint32_t timeout )
+{
+    //Block until the FIFO is NOT full.
+    //Keep track of the MAX retries and set auto-retry if seeing failures
+    //This way the FIFO will fill up and allow blocking until packets go through
+    //The radio will auto-clear everything in the FIFO as long as CE remains high
+ 
+    uint32_t timer = mainTimer.read_ms();                             //Get the time that the payload transmission started
+ 
+    while( ( get_status()  & ( _BV(TX_FULL) ))) {         //Blocking only if FIFO is full. This will loop and block until TX is successful or timeout
+ 
+        if( get_status() & _BV(MAX_RT)){                      //If MAX Retries have been reached
+            reUseTX();                                        //Set re-transmit and clear the MAX_RT interrupt flag
+            if(mainTimer.read_ms() - timer > timeout){ return 0; }        //If this payload has exceeded the user-defined timeout, exit and return 0
+        }
+        #if defined (FAILURE_HANDLING) || defined (RF24_LINUX)
+            if(mainTimer.read_ms() - timer > (timeout+95) ){            
+                errNotify();
+                #if defined (FAILURE_HANDLING)
+                return 0;           
+                #endif              
+            }
+        #endif
+ 
+    }
+ 
+    //Start Writing
+    startFastWrite(buf,len,0);                                //Write the payload if a buffer is clear
+ 
+    return 1;                                                 //Return 1 to indicate successful transmission
+}
+ 
+/****************************************************************************/
+ 
+void RF24::reUseTX(){
+        write_register(NRF_STATUS,_BV(MAX_RT) );              //Clear max retry flag
+        spiTrans( REUSE_TX_PL );
+        ce(LOW);                                          //Re-Transfer packet
+        ce(HIGH);
+}
+ 
+/****************************************************************************/
+ 
+bool RF24::writeFast( const void* buf, uint8_t len, const bool multicast )
+{
+    //Block until the FIFO is NOT full.
+    //Keep track of the MAX retries and set auto-retry if seeing failures
+    //Return 0 so the user can control the retrys and set a timer or failure counter if required
+    //The radio will auto-clear everything in the FIFO as long as CE remains high
+ 
+    #if defined (FAILURE_HANDLING) || defined (RF24_LINUX)
+        uint32_t timer = mainTimer.read_ms();
+    #endif
+    
+    while( ( get_status()  & ( _BV(TX_FULL) ))) {             //Blocking only if FIFO is full. This will loop and block until TX is successful or fail
+ 
+        if( get_status() & _BV(MAX_RT)){
+            //reUseTX();                                          //Set re-transmit
+            write_register(NRF_STATUS,_BV(MAX_RT) );              //Clear max retry flag
+            return 0;                                         //Return 0. The previous payload has been retransmitted
+                                                              //From the user perspective, if you get a 0, just keep trying to send the same payload
+        }
+        #if defined (FAILURE_HANDLING) || defined (RF24_LINUX)
+            if(mainTimer.read_ms() - timer > 95 ){          
+                errNotify();
+                #if defined (FAILURE_HANDLING)
+                return 0;                           
+                #endif
+            }
+        #endif
+    }
+             //Start Writing
+    startFastWrite(buf,len,multicast);
+ 
+    return 1;
+}
+ 
+bool RF24::writeFast( const void* buf, uint8_t len ){
+    return writeFast(buf,len,0);
+}
+ 
+/****************************************************************************/
+ 
+//Per the documentation, we want to set PTX Mode when not listening. Then all we do is write data and set CE high
+//In this mode, if we can keep the FIFO buffers loaded, packets will transmit immediately (no 130us delay)
+//Otherwise we enter Standby-II mode, which is still faster than standby mode
+//Also, we remove the need to keep writing the config register over and over and delaying for 150 us each time if sending a stream of data
+ 
+void RF24::startFastWrite( const void* buf, uint8_t len, const bool multicast, bool startTx){ //TMRh20
+ 
+    //write_payload( buf,len);
+    write_payload( buf, len,multicast ? W_TX_PAYLOAD_NO_ACK : W_TX_PAYLOAD ) ;
+    if(startTx){
+        ce(HIGH);
+    }
+ 
+}
+ 
+/****************************************************************************/
+ 
+//Added the original startWrite back in so users can still use interrupts, ack payloads, etc
+//Allows the library to pass all tests
+void RF24::startWrite( const void* buf, uint8_t len, const bool multicast ){
+ 
+  // Send the payload
+ 
+  //write_payload( buf, len );
+  write_payload( buf, len,multicast? W_TX_PAYLOAD_NO_ACK : W_TX_PAYLOAD ) ;
+  ce(HIGH);
+  
+  wait_us(10);
+  
+  ce(LOW);
+ 
+ 
+}
+ 
+/****************************************************************************/
+ 
+bool RF24::rxFifoFull(){
+    return read_register(FIFO_STATUS) & _BV(RX_FULL);
+}
+/****************************************************************************/
+ 
+bool RF24::txStandBy(){
+ 
+    #if defined (FAILURE_HANDLING) || defined (RF24_LINUX)
+        uint32_t timeout = mainTimer.read_ms();
+    #endif
+    while( ! (read_register(FIFO_STATUS) & _BV(TX_EMPTY)) ){
+        if( get_status() & _BV(MAX_RT)){
+            write_register(NRF_STATUS,_BV(MAX_RT) );
+            ce(LOW);
+            flush_tx();    //Non blocking, flush the data
+            return 0;
+        }
+        #if defined (FAILURE_HANDLING) || defined (RF24_LINUX)
+            if( mainTimer.read_ms() - timeout > 95){
+                errNotify();
+                #if defined (FAILURE_HANDLING)
+                return 0;   
+                #endif
+            }
+        #endif
+    }
+ 
+    ce(LOW);               //Set STANDBY-I mode
+    return 1;
+}
+ 
+/****************************************************************************/
+ 
+bool RF24::txStandBy(uint32_t timeout, bool startTx){
+ 
+    if(startTx){
+      stopListening();
+      ce(HIGH);
+    }
+    uint32_t start = mainTimer.read_ms();
+ 
+    while( ! (read_register(FIFO_STATUS) & _BV(TX_EMPTY)) ){
+        if( get_status() & _BV(MAX_RT)){
+            write_register(NRF_STATUS,_BV(MAX_RT) );
+                ce(LOW);                                          //Set re-transmit
+                ce(HIGH);
+                if(mainTimer.read_ms() - start >= timeout){
+                    ce(LOW); flush_tx(); return 0;
+                }
+        }
+        #if defined (FAILURE_HANDLING) || defined (RF24_LINUX)
+            if( mainTimer.read_ms() - start > (timeout+95)){
+                errNotify();
+                #if defined (FAILURE_HANDLING)
+                return 0;   
+                #endif
+            }
+        #endif
+    }
+ 
+    
+    ce(LOW);                   //Set STANDBY-I mode
+    return 1;
+ 
+}
+ 
+/****************************************************************************/
+ 
+void RF24::maskIRQ(bool tx, bool fail, bool rx){
+ 
+    uint8_t config = read_register(NRF_CONFIG);
+    /* clear the interrupt flags */
+    config &= ~(1 << MASK_MAX_RT | 1 << MASK_TX_DS | 1 << MASK_RX_DR);
+    /* set the specified interrupt flags */
+    config |= fail << MASK_MAX_RT | tx << MASK_TX_DS | rx << MASK_RX_DR;
+    write_register(NRF_CONFIG, config);
+}
+ 
+/****************************************************************************/
+ 
+uint8_t RF24::getDynamicPayloadSize(void)
+{
+  uint8_t result = 0;
+ 
+  
+  beginTransaction();
+  spi.write( R_RX_PL_WID );
+  result = spi.write(0xff);
+  endTransaction();
+  
+ 
+  if(result > 32) { flush_rx(); wait_ms(2); return 0; }
+  return result;
+}
+ 
+/****************************************************************************/
+ 
+bool RF24::available(void)
+{
+  return available(NULL);
+}
+ 
+/****************************************************************************/
+ 
+bool RF24::available(uint8_t* pipe_num)
+{
+  if (!( read_register(FIFO_STATUS) & _BV(RX_EMPTY) )){
+ 
+    // If the caller wants the pipe number, include that
+    if ( pipe_num ){
+      uint8_t status = get_status();
+      *pipe_num = ( status >> RX_P_NO ) & 0b111;
+    }
+    return 1;
+  }
+ 
+ 
+  return 0;
+ 
+ 
+}
+ 
+/****************************************************************************/
+ 
+void RF24::read( void* buf, uint8_t len ){
+ 
+  // Fetch the payload
+  read_payload( buf, len );
+ 
+  //Clear the two possible interrupt flags with one command
+  write_register(NRF_STATUS,_BV(RX_DR) | _BV(MAX_RT) | _BV(TX_DS) );
+ 
+}
+ 
+/****************************************************************************/
+ 
+void RF24::whatHappened(bool& tx_ok,bool& tx_fail,bool& rx_ready)
+{
+  // Read the status & reset the status in one easy call
+  // Or is that such a good idea?
+  uint8_t status = write_register(NRF_STATUS,_BV(RX_DR) | _BV(TX_DS) | _BV(MAX_RT) );
+ 
+  // Report to the user what happened
+  tx_ok = status & _BV(TX_DS);
+  tx_fail = status & _BV(MAX_RT);
+  rx_ready = status & _BV(RX_DR);
+}
+ 
+/****************************************************************************/
+ 
+void RF24::openWritingPipe(uint64_t value)
+{
+  // Note that AVR 8-bit uC's store this LSB first, and the NRF24L01(+)
+  // expects it LSB first too, so we're good.
+ 
+  write_register(RX_ADDR_P0, reinterpret_cast<uint8_t*>(&value), addr_width);
+  write_register(TX_ADDR, reinterpret_cast<uint8_t*>(&value), addr_width);
+  
+  
+  //const uint8_t max_payload_size = 32;
+  //write_register(RX_PW_P0,rf24_min(payload_size,max_payload_size));
+  write_register(RX_PW_P0,payload_size);
+}
+ 
+/****************************************************************************/
+void RF24::openWritingPipe(const uint8_t *address)
+{
+  // Note that AVR 8-bit uC's store this LSB first, and the NRF24L01(+)
+  // expects it LSB first too, so we're good.
+ 
+  write_register(RX_ADDR_P0,address, addr_width);
+  write_register(TX_ADDR, address, addr_width);
+ 
+  //const uint8_t max_payload_size = 32;
+  //write_register(RX_PW_P0,rf24_min(payload_size,max_payload_size));
+  write_register(RX_PW_P0,payload_size);
+}
+ 
+/****************************************************************************/
+static const uint8_t child_pipe[] PROGMEM =
+{
+  RX_ADDR_P0, RX_ADDR_P1, RX_ADDR_P2, RX_ADDR_P3, RX_ADDR_P4, RX_ADDR_P5
+};
+static const uint8_t child_payload_size[] PROGMEM =
+{
+  RX_PW_P0, RX_PW_P1, RX_PW_P2, RX_PW_P3, RX_PW_P4, RX_PW_P5
+};
+ 
+ 
+void RF24::openReadingPipe(uint8_t child, uint64_t address)
+{
+  // If this is pipe 0, cache the address.  This is needed because
+  // openWritingPipe() will overwrite the pipe 0 address, so
+  // startListening() will have to restore it.
+  if (child == 0){
+    memcpy(pipe0_reading_address,&address,addr_width);
+  }
+ 
+  if (child <= 6)
+  {
+    // For pipes 2-5, only write the LSB
+    if ( child < 2 )
+      write_register(pgm_read_byte(&child_pipe[child]), reinterpret_cast<const uint8_t*>(&address), addr_width);
+    else
+      write_register(pgm_read_byte(&child_pipe[child]), reinterpret_cast<const uint8_t*>(&address), 1);
+ 
+    write_register(pgm_read_byte(&child_payload_size[child]),payload_size);
+ 
+    // Note it would be more efficient to set all of the bits for all open
+    // pipes at once.  However, I thought it would make the calling code
+    // more simple to do it this way.
+    write_register(EN_RXADDR,read_register(EN_RXADDR) | _BV(pgm_read_byte(&child_pipe_enable[child])));
+  }
+}
+ 
+/****************************************************************************/
+void RF24::setAddressWidth(uint8_t a_width){
+ 
+    if(a_width -= 2){
+        write_register(SETUP_AW,a_width%4);
+        addr_width = (a_width%4) + 2;
+    }
+ 
+}
+ 
+/****************************************************************************/
+ 
+void RF24::openReadingPipe(uint8_t child, const uint8_t *address)
+{
+  // If this is pipe 0, cache the address.  This is needed because
+  // openWritingPipe() will overwrite the pipe 0 address, so
+  // startListening() will have to restore it.
+  if (child == 0){
+    memcpy(pipe0_reading_address,address,addr_width);
+  }
+  if (child <= 6)
+  {
+    // For pipes 2-5, only write the LSB
+    if ( child < 2 ){
+      write_register(pgm_read_byte(&child_pipe[child]), address, addr_width);
+    }else{
+      write_register(pgm_read_byte(&child_pipe[child]), address, 1);
+    }
+    write_register(pgm_read_byte(&child_payload_size[child]),payload_size);
+ 
+    // Note it would be more efficient to set all of the bits for all open
+    // pipes at once.  However, I thought it would make the calling code
+    // more simple to do it this way.
+    write_register(EN_RXADDR,read_register(EN_RXADDR) | _BV(pgm_read_byte(&child_pipe_enable[child])));
+ 
+  }
+}
+ 
+/****************************************************************************/
+ 
+void RF24::closeReadingPipe( uint8_t pipe )
+{
+  write_register(EN_RXADDR,read_register(EN_RXADDR) & ~_BV(pgm_read_byte(&child_pipe_enable[pipe])));
+}
+ 
+/****************************************************************************/
+ 
+void RF24::toggle_features(void)
+{
+    beginTransaction();
+    spi.write( ACTIVATE );
+    spi.write( 0x73 );
+    endTransaction();
+}
+ 
+/****************************************************************************/
+ 
+void RF24::enableDynamicPayloads(void)
+{
+  // Enable dynamic payload throughout the system
+ 
+    //toggle_features();
+    write_register(FEATURE,read_register(FEATURE) | _BV(EN_DPL) );
+ 
+ 
+  IF_SERIAL_DEBUG(printf("FEATURE=%i\r\n",read_register(FEATURE)));
+ 
+  // Enable dynamic payload on all pipes
+  //
+  // Not sure the use case of only having dynamic payload on certain
+  // pipes, so the library does not support it.
+  write_register(DYNPD,read_register(DYNPD) | _BV(DPL_P5) | _BV(DPL_P4) | _BV(DPL_P3) | _BV(DPL_P2) | _BV(DPL_P1) | _BV(DPL_P0));
+ 
+  dynamic_payloads_enabled = true;
+}
+ 
+/****************************************************************************/
+ 
+void RF24::enableAckPayload(void)
+{
+  //
+  // enable ack payload and dynamic payload features
+  //
+ 
+    //toggle_features();
+    write_register(FEATURE,read_register(FEATURE) | _BV(EN_ACK_PAY) | _BV(EN_DPL) );
+ 
+  IF_SERIAL_DEBUG(printf("FEATURE=%i\r\n",read_register(FEATURE)));
+ 
+  //
+  // Enable dynamic payload on pipes 0 & 1
+  //
+ 
+  write_register(DYNPD,read_register(DYNPD) | _BV(DPL_P1) | _BV(DPL_P0));
+  dynamic_payloads_enabled = true;
+}
+ 
+/****************************************************************************/
+ 
+void RF24::enableDynamicAck(void){
+  //
+  // enable dynamic ack features
+  //
+    //toggle_features();
+    write_register(FEATURE,read_register(FEATURE) | _BV(EN_DYN_ACK) );
+ 
+  IF_SERIAL_DEBUG(printf("FEATURE=%i\r\n",read_register(FEATURE)));
+ 
+ 
+}
+ 
+/****************************************************************************/
+ 
+void RF24::writeAckPayload(uint8_t pipe, const void* buf, uint8_t len)
+{
+  const uint8_t* current = reinterpret_cast<const uint8_t*>(buf);
+ 
+  uint8_t data_len = rf24_min(len,32);
+ 
+   
+  
+  beginTransaction();
+  spi.write(W_ACK_PAYLOAD | ( pipe & 0b111 ) );
+ 
+  while ( data_len-- )
+    spi.write(*current++);
+  endTransaction();
+    
+   
+ 
+}
+ 
+/****************************************************************************/
+ 
+bool RF24::isAckPayloadAvailable(void)
+{
+  return ! (read_register(FIFO_STATUS) & _BV(RX_EMPTY));
+}
+ 
+/****************************************************************************/
+ 
+bool RF24::isPVariant(void)
+{
+  return p_variant ;
+}
+ 
+/****************************************************************************/
+ 
+void RF24::setAutoAck(bool enable)
+{
+  if ( enable )
+    write_register(EN_AA, 0b111111);
+  else
+    write_register(EN_AA, 0);
+}
+ 
+/****************************************************************************/
+ 
+void RF24::setAutoAck( uint8_t pipe, bool enable )
+{
+  if ( pipe <= 6 )
+  {
+    uint8_t en_aa = read_register( EN_AA ) ;
+    if( enable )
+    {
+      en_aa |= _BV(pipe) ;
+    }
+    else
+    {
+      en_aa &= ~_BV(pipe) ;
+    }
+    write_register( EN_AA, en_aa ) ;
+  }
+}
+ 
+/****************************************************************************/
+ 
+bool RF24::testCarrier(void)
+{
+  return ( read_register(CD) & 1 );
+}
+ 
+/****************************************************************************/
+ 
+bool RF24::testRPD(void)
+{
+  return ( read_register(RPD) & 1 ) ;
+}
+ 
+/****************************************************************************/
+ 
+void RF24::setPALevel(uint8_t level)
+{
+ 
+  uint8_t setup = read_register(RF_SETUP) & 0b11111000;
+ 
+  if(level > 3){                        // If invalid level, go to max PA
+      level = (RF24_PA_MAX << 1) + 1;       // +1 to support the SI24R1 chip extra bit
+  }else{
+      level = (level << 1) + 1;         // Else set level as requested
+  }
+ 
+ 
+  write_register( RF_SETUP, setup |= level ) ;  // Write it to the chip
+}
+ 
+/****************************************************************************/
+ 
+uint8_t RF24::getPALevel(void)
+{
+ 
+  return (read_register(RF_SETUP) & (_BV(RF_PWR_LOW) | _BV(RF_PWR_HIGH))) >> 1 ;
+}
+ 
+/****************************************************************************/
+ 
+bool RF24::setDataRate(rf24_datarate_e speed)
+{
+  bool result = false;
+  uint8_t setup = read_register(RF_SETUP) ;
+ 
+  // HIGH and LOW '00' is 1Mbs - our default
+  setup &= ~(_BV(RF_DR_LOW) | _BV(RF_DR_HIGH)) ;
+  
+  
+  
+  
+    txRxDelay=85;
+ 
+  if( speed == RF24_250KBPS )
+  {
+    // Must set the RF_DR_LOW to 1; RF_DR_HIGH (used to be RF_DR) is already 0
+    // Making it '10'.
+    setup |= _BV( RF_DR_LOW ) ;
+ 
+ 
+ 
+    txRxDelay=155;
+ 
+  }
+  else
+  {
+    // Set 2Mbs, RF_DR (RF_DR_HIGH) is set 1
+    // Making it '01'
+    if ( speed == RF24_2MBPS )
+    {
+      setup |= _BV(RF_DR_HIGH);
+      
+      
+      //txRxDelay=65;
+      txRxDelay=15; //mbed works fine with this latency
+      
+    }
+  }
+  write_register(RF_SETUP,setup);
+ 
+  // Verify our result
+  if ( read_register(RF_SETUP) == setup )
+  {
+    result = true;
+  }
+  return result;
+}
+ 
+/****************************************************************************/
+ 
+rf24_datarate_e RF24::getDataRate( void )
+{
+  rf24_datarate_e result ;
+  uint8_t dr = read_register(RF_SETUP) & (_BV(RF_DR_LOW) | _BV(RF_DR_HIGH));
+ 
+  // switch uses RAM (evil!)
+  // Order matters in our case below
+  if ( dr == _BV(RF_DR_LOW) )
+  {
+    // '10' = 250KBPS
+    result = RF24_250KBPS ;
+  }
+  else if ( dr == _BV(RF_DR_HIGH) )
+  {
+    // '01' = 2MBPS
+    result = RF24_2MBPS ;
+  }
+  else
+  {
+    // '00' = 1MBPS
+    result = RF24_1MBPS ;
+  }
+  return result ;
+}
+ 
+/****************************************************************************/
+ 
+void RF24::setCRCLength(rf24_crclength_e length)
+{
+  uint8_t config = read_register(NRF_CONFIG) & ~( _BV(CRCO) | _BV(EN_CRC)) ;
+ 
+  // switch uses RAM (evil!)
+  if ( length == RF24_CRC_DISABLED )
+  {
+    // Do nothing, we turned it off above.
+  }
+  else if ( length == RF24_CRC_8 )
+  {
+    config |= _BV(EN_CRC);
+  }
+  else
+  {
+    config |= _BV(EN_CRC);
+    config |= _BV( CRCO );
+  }
+  write_register( NRF_CONFIG, config ) ;
+}
+ 
+/****************************************************************************/
+ 
+rf24_crclength_e RF24::getCRCLength(void)
+{
+  rf24_crclength_e result = RF24_CRC_DISABLED;
+  
+  uint8_t config = read_register(NRF_CONFIG) & ( _BV(CRCO) | _BV(EN_CRC)) ;
+  uint8_t AA = read_register(EN_AA);
+  
+  if ( config & _BV(EN_CRC ) || AA)
+  {
+    if ( config & _BV(CRCO) )
+      result = RF24_CRC_16;
+    else
+      result = RF24_CRC_8;
+  }
+ 
+  return result;
+}
+ 
+/****************************************************************************/
+ 
+void RF24::disableCRC( void )
+{
+  uint8_t disable = read_register(NRF_CONFIG) & ~_BV(EN_CRC) ;
+  write_register( NRF_CONFIG, disable ) ;
+}
+ 
+/****************************************************************************/
+void RF24::setRetries(uint8_t delay, uint8_t count)
+{
+ write_register(SETUP_RETR,(delay&0xf)<<ARD | (count&0xf)<<ARC);
+}
+
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/RF24.h	Sat Dec 03 08:21:37 2022 +0000
@@ -0,0 +1,1864 @@
+/*
+ Copyright (C) 2011 J. Coliz <maniacbug@ymail.com>
+ 
+ This program is free software; you can redistribute it and/or
+ modify it under the terms of the GNU General Public License
+ version 2 as published by the Free Software Foundation.
+ */
+ 
+/**
+ * @file RF24.h
+ *
+ * Class declaration for RF24 and helper enums
+ */
+ 
+/*
+ * Mbed support added by Akash Vibhute <akash.roboticist@gmail.com>
+ * Porting completed on Nov/05/2015
+ *
+ * Updated 1: Synced with TMRh20's RF24 library on Nov/04/2015 from https://github.com/TMRh20
+ * Updated 2: Synced with TMRh20's RF24 library on Apr/18/2015 from https://github.com/TMRh20
+ *
+ */
+ 
+#ifndef __RF24_H__
+#define __RF24_H__
+ 
+#include "RF24_config.h"
+#include <mbed.h>
+ 
+ 
+ 
+/**
+ * Power Amplifier level.
+ *
+ * For use with setPALevel()
+ */
+typedef enum { RF24_PA_MIN = 0,RF24_PA_LOW, RF24_PA_HIGH, RF24_PA_MAX, RF24_PA_ERROR } rf24_pa_dbm_e ;
+ 
+/**
+ * Data rate.  How fast data moves through the air.
+ *
+ * For use with setDataRate()
+ */
+typedef enum { RF24_1MBPS = 0, RF24_2MBPS, RF24_250KBPS } rf24_datarate_e;
+ 
+/**
+ * CRC Length.  How big (if any) of a CRC is included.
+ *
+ * For use with setCRCLength()
+ */
+typedef enum { RF24_CRC_DISABLED = 0, RF24_CRC_8, RF24_CRC_16 } rf24_crclength_e;
+ 
+/**
+ * Driver for nRF24L01(+) 2.4GHz Wireless Transceiver
+ */
+ 
+class RF24
+{
+private:
+  DigitalOut ce_pin; /**< "Chip Enable" pin, activates the RX or TX role */
+  DigitalOut csn_pin; /**< SPI Chip select */
+  uint16_t spi_speed; /**< SPI Bus Speed */
+    
+  SPI spi;
+  Timer mainTimer;
+  
+  bool p_variant; /* False for RF24L01 and true for RF24L01P */
+  uint8_t payload_size; /**< Fixed size of payloads */
+  bool dynamic_payloads_enabled; /**< Whether dynamic payloads are enabled. */
+  uint8_t pipe0_reading_address[5]; /**< Last address set on pipe 0 for reading. */
+  uint8_t addr_width; /**< The address width to use - 3,4 or 5 bytes. */
+  uint32_t txRxDelay; /**< Var for adjusting delays depending on datarate */
+  
+ 
+protected:
+  /**
+   * SPI transactions
+   *
+   * Common code for SPI transactions including CSN toggle
+   *
+   */
+  inline void beginTransaction();
+ 
+  inline void endTransaction();
+ 
+public:
+ 
+  /**
+   * @name Primary public interface
+   *
+   *  These are the main methods you need to operate the chip
+   */
+  /**@{*/
+ 
+  /**
+   * Arduino Constructor
+   *
+   * Creates a new instance of this driver.  Before using, you create an instance
+   * and send in the unique pins that this chip is connected to.
+   *
+   * @param _cepin The pin attached to Chip Enable on the RF module
+   * @param _cspin The pin attached to Chip Select
+   */
+  RF24(PinName mosi, PinName miso, PinName sck, PinName _cepin, PinName _csnpin);
+ 
+ 
+  /**
+   * Begin operation of the chip
+   * 
+   * Call this in setup(), before calling any other methods.
+   * @code radio.begin() @endcode
+   */
+  bool begin(void);
+ 
+  /**
+   * Start listening on the pipes opened for reading.
+   *
+   * 1. Be sure to call openReadingPipe() first.  
+   * 2. Do not call write() while in this mode, without first calling stopListening().
+   * 3. Call available() to check for incoming traffic, and read() to get it. 
+   *  
+   * @code
+   * Open reading pipe 1 using address CCCECCCECC
+   *  
+   * byte address[] = { 0xCC,0xCE,0xCC,0xCE,0xCC };
+   * radio.openReadingPipe(1,address);
+   * radio.startListening();
+   * @endcode
+   */
+  void startListening(void);
+ 
+  /**
+   * Stop listening for incoming messages, and switch to transmit mode.
+   *
+   * Do this before calling write().
+   * @code
+   * radio.stopListening();
+   * radio.write(&data,sizeof(data));
+   * @endcode
+   */
+  void stopListening(void);
+ 
+  /**
+   * Check whether there are bytes available to be read
+   * @code
+   * if(radio.available()){
+   *   radio.read(&data,sizeof(data));
+   * }
+   * @endcode
+   * @return True if there is a payload available, false if none is
+   */
+  bool available(void);
+ 
+  /**
+   * Read the available payload
+   *
+   * The size of data read is the fixed payload size, see getPayloadSize()
+   *
+   * @note I specifically chose 'void*' as a data type to make it easier
+   * for beginners to use.  No casting needed.
+   *
+   * @note No longer boolean. Use available to determine if packets are
+   * available. Interrupt flags are now cleared during reads instead of
+   * when calling available().
+   *
+   * @param buf Pointer to a buffer where the data should be written
+   * @param len Maximum number of bytes to read into the buffer
+   *
+   * @code
+   * if(radio.available()){
+   *   radio.read(&data,sizeof(data));
+   * }
+   * @endcode
+   * @return No return value. Use available().
+   */
+  void read( void* buf, uint8_t len );
+ 
+  /**
+   * Be sure to call openWritingPipe() first to set the destination
+   * of where to write to.
+   *
+   * This blocks until the message is successfully acknowledged by
+   * the receiver or the timeout/retransmit maxima are reached.  In
+   * the current configuration, the max delay here is 60-70ms.
+   *
+   * The maximum size of data written is the fixed payload size, see
+   * getPayloadSize().  However, you can write less, and the remainder
+   * will just be filled with zeroes.
+   *
+   * TX/RX/RT interrupt flags will be cleared every time write is called
+   *
+   * @param buf Pointer to the data to be sent
+   * @param len Number of bytes to be sent
+   *
+   * @code
+   * radio.stopListening();
+   * radio.write(&data,sizeof(data));
+   * @endcode
+   * @return True if the payload was delivered successfully false if not
+   */
+  bool write( const void* buf, uint8_t len );
+ 
+  /**
+   * New: Open a pipe for writing via byte array. Old addressing format retained
+   * for compatibility.
+   *
+   * Only one writing pipe can be open at once, but you can change the address
+   * you'll write to. Call stopListening() first.
+   *
+   * Addresses are assigned via a byte array, default is 5 byte address length
+s   *
+   * @code
+   *   uint8_t addresses[][6] = {"1Node","2Node"};
+   *   radio.openWritingPipe(addresses[0]);
+   * @endcode
+   * @code
+   *  uint8_t address[] = { 0xCC,0xCE,0xCC,0xCE,0xCC };
+   *  radio.openWritingPipe(address);
+   *  address[0] = 0x33;
+   *  radio.openReadingPipe(1,address);
+   * @endcode
+   * @see setAddressWidth
+   *
+   * @param address The address of the pipe to open. Coordinate these pipe
+   * addresses amongst nodes on the network.
+   */
+ 
+  void openWritingPipe(const uint8_t *address);
+ 
+  /**
+   * Open a pipe for reading
+   *
+   * Up to 6 pipes can be open for reading at once.  Open all the required
+   * reading pipes, and then call startListening().
+   *
+   * @see openWritingPipe
+   * @see setAddressWidth
+   *
+   * @note Pipes 0 and 1 will store a full 5-byte address. Pipes 2-5 will technically 
+   * only store a single byte, borrowing up to 4 additional bytes from pipe #1 per the
+   * assigned address width.
+   * @warning Pipes 1-5 should share the same address, except the first byte.
+   * Only the first byte in the array should be unique, e.g.
+   * @code
+   *   uint8_t addresses[][6] = {"1Node","2Node"};
+   *   openReadingPipe(1,addresses[0]);
+   *   openReadingPipe(2,addresses[1]);
+   * @endcode
+   *
+   * @warning Pipe 0 is also used by the writing pipe.  So if you open
+   * pipe 0 for reading, and then startListening(), it will overwrite the
+   * writing pipe.  Ergo, do an openWritingPipe() again before write().
+   *
+   * @param number Which pipe# to open, 0-5.
+   * @param address The 24, 32 or 40 bit address of the pipe to open.
+   */
+ 
+  void openReadingPipe(uint8_t number, const uint8_t *address);
+ 
+   /**@}*/
+  /**
+   * @name Advanced Operation
+   *
+   *  Methods you can use to drive the chip in more advanced ways
+   */
+  /**@{*/
+ 
+  /**
+   * Print a giant block of debugging information to stdout
+   *
+   * @warning Does nothing if stdout is not defined.  See fdevopen in stdio.h
+   * The printf.h file is included with the library for Arduino.
+   * @code
+   * #include <printf.h>
+   * setup(){
+   *  Serial.begin(115200);
+   *  printf_begin();
+   *  ...
+   * }
+   * @endcode
+   */
+  void printDetails(void);
+ 
+  /**
+   * Test whether there are bytes available to be read in the
+   * FIFO buffers. 
+   *
+   * @param[out] pipe_num Which pipe has the payload available
+   *  
+   * @code
+   * uint8_t pipeNum;
+   * if(radio.available(&pipeNum)){
+   *   radio.read(&data,sizeof(data));
+   *   Serial.print("Got data on pipe");
+   *   Serial.println(pipeNum);
+   * }
+   * @endcode
+   * @return True if there is a payload available, false if none is
+   */
+  bool available(uint8_t* pipe_num);
+ 
+  /**
+   * Check if the radio needs to be read. Can be used to prevent data loss
+   * @return True if all three 32-byte radio buffers are full
+   */
+  bool rxFifoFull();
+ 
+  /**
+   * Enter low-power mode
+   *
+   * To return to normal power mode, call powerUp().
+   *
+   * @note After calling startListening(), a basic radio will consume about 13.5mA
+   * at max PA level.
+   * During active transmission, the radio will consume about 11.5mA, but this will
+   * be reduced to 26uA (.026mA) between sending.
+   * In full powerDown mode, the radio will consume approximately 900nA (.0009mA)   
+   *
+   * @code
+   * radio.powerDown();
+   * avr_enter_sleep_mode(); // Custom function to sleep the device
+   * radio.powerUp();
+   * @endcode
+   */
+  void powerDown(void);
+ 
+  /**
+   * Leave low-power mode - required for normal radio operation after calling powerDown()
+   * 
+   * To return to low power mode, call powerDown().
+   * @note This will take up to 5ms for maximum compatibility 
+   */
+  void powerUp(void) ;
+ 
+  /**
+  * Write for single NOACK writes. Optionally disables acknowledgements/autoretries for a single write.
+  *
+  * @note enableDynamicAck() must be called to enable this feature
+  *
+  * Can be used with enableAckPayload() to request a response
+  * @see enableDynamicAck()
+  * @see setAutoAck()
+  * @see write()
+  *
+  * @param buf Pointer to the data to be sent
+  * @param len Number of bytes to be sent
+  * @param multicast Request ACK (0), NOACK (1)
+  */
+  bool write( const void* buf, uint8_t len, const bool multicast );
+ 
+  /**
+   * This will not block until the 3 FIFO buffers are filled with data.
+   * Once the FIFOs are full, writeFast will simply wait for success or
+   * timeout, and return 1 or 0 respectively. From a user perspective, just
+   * keep trying to send the same data. The library will keep auto retrying
+   * the current payload using the built in functionality.
+   * @warning It is important to never keep the nRF24L01 in TX mode and FIFO full for more than 4ms at a time. If the auto
+   * retransmit is enabled, the nRF24L01 is never in TX mode long enough to disobey this rule. Allow the FIFO
+   * to clear by issuing txStandBy() or ensure appropriate time between transmissions.
+   *
+   * @code
+   * Example (Partial blocking):
+   *
+   *            radio.writeFast(&buf,32);  // Writes 1 payload to the buffers
+   *            txStandBy();               // Returns 0 if failed. 1 if success. Blocks only until MAX_RT timeout or success. Data flushed on fail.
+   *
+   *            radio.writeFast(&buf,32);  // Writes 1 payload to the buffers
+   *            txStandBy(1000);           // Using extended timeouts, returns 1 if success. Retries failed payloads for 1 seconds before returning 0.
+   * @endcode
+   *
+   * @see txStandBy()
+   * @see write()
+   * @see writeBlocking()
+   *
+   * @param buf Pointer to the data to be sent
+   * @param len Number of bytes to be sent
+   * @return True if the payload was delivered successfully false if not
+   */
+  bool writeFast( const void* buf, uint8_t len );
+ 
+  /**
+  * WriteFast for single NOACK writes. Disables acknowledgements/autoretries for a single write.
+  *
+  * @note enableDynamicAck() must be called to enable this feature
+  * @see enableDynamicAck()
+  * @see setAutoAck()
+  *
+  * @param buf Pointer to the data to be sent
+  * @param len Number of bytes to be sent
+  * @param multicast Request ACK (0) or NOACK (1)
+  */
+  bool writeFast( const void* buf, uint8_t len, const bool multicast );
+ 
+  /**
+   * This function extends the auto-retry mechanism to any specified duration.
+   * It will not block until the 3 FIFO buffers are filled with data.
+   * If so the library will auto retry until a new payload is written
+   * or the user specified timeout period is reached.
+   * @warning It is important to never keep the nRF24L01 in TX mode and FIFO full for more than 4ms at a time. If the auto
+   * retransmit is enabled, the nRF24L01 is never in TX mode long enough to disobey this rule. Allow the FIFO
+   * to clear by issuing txStandBy() or ensure appropriate time between transmissions.
+   *
+   * @code
+   * Example (Full blocking):
+   *
+   *            radio.writeBlocking(&buf,32,1000); //Wait up to 1 second to write 1 payload to the buffers
+   *            txStandBy(1000);                   //Wait up to 1 second for the payload to send. Return 1 if ok, 0 if failed.
+   *                                               //Blocks only until user timeout or success. Data flushed on fail.
+   * @endcode
+   * @note If used from within an interrupt, the interrupt should be disabled until completion, and sei(); called to enable millis().
+   * @see txStandBy()
+   * @see write()
+   * @see writeFast()
+   *
+   * @param buf Pointer to the data to be sent
+   * @param len Number of bytes to be sent
+   * @param timeout User defined timeout in milliseconds.
+   * @return True if the payload was loaded into the buffer successfully false if not
+   */
+  bool writeBlocking( const void* buf, uint8_t len, uint32_t timeout );
+ 
+  /**
+   * This function should be called as soon as transmission is finished to
+   * drop the radio back to STANDBY-I mode. If not issued, the radio will
+   * remain in STANDBY-II mode which, per the data sheet, is not a recommended
+   * operating mode.
+   *
+   * @note When transmitting data in rapid succession, it is still recommended by
+   * the manufacturer to drop the radio out of TX or STANDBY-II mode if there is
+   * time enough between sends for the FIFOs to empty. This is not required if auto-ack
+   * is enabled.
+   *
+   * Relies on built-in auto retry functionality.
+   *
+   * @code
+   * Example (Partial blocking):
+   *
+   *            radio.writeFast(&buf,32);
+   *            radio.writeFast(&buf,32);
+   *            radio.writeFast(&buf,32);  //Fills the FIFO buffers up
+   *            bool ok = txStandBy();     //Returns 0 if failed. 1 if success.
+   *                                       //Blocks only until MAX_RT timeout or success. Data flushed on fail.
+   * @endcode
+   * @see txStandBy(unsigned long timeout)
+   * @return True if transmission is successful
+   *
+   */
+   bool txStandBy();
+ 
+  /**
+   * This function allows extended blocking and auto-retries per a user defined timeout
+   * @code
+   *    Fully Blocking Example:
+   *
+   *            radio.writeFast(&buf,32);
+   *            radio.writeFast(&buf,32);
+   *            radio.writeFast(&buf,32);   //Fills the FIFO buffers up
+   *            bool ok = txStandBy(1000);  //Returns 0 if failed after 1 second of retries. 1 if success.
+   *                                        //Blocks only until user defined timeout or success. Data flushed on fail.
+   * @endcode
+   * @note If used from within an interrupt, the interrupt should be disabled until completion, and sei(); called to enable millis().
+   * @param timeout Number of milliseconds to retry failed payloads
+   * @return True if transmission is successful
+   *
+   */
+   bool txStandBy(uint32_t timeout, bool startTx = 0);
+ 
+  /**
+   * Write an ack payload for the specified pipe
+   *
+   * The next time a message is received on @p pipe, the data in @p buf will
+   * be sent back in the acknowledgement.
+   * @see enableAckPayload()
+   * @see enableDynamicPayloads()
+   * @warning Only three of these can be pending at any time as there are only 3 FIFO buffers.<br> Dynamic payloads must be enabled.
+   * @note Ack payloads are handled automatically by the radio chip when a payload is received. Users should generally
+   * write an ack payload as soon as startListening() is called, so one is available when a regular payload is received.
+   * @note Ack payloads are dynamic payloads. This only works on pipes 0&1 by default. Call 
+   * enableDynamicPayloads() to enable on all pipes.
+   *
+   * @param pipe Which pipe# (typically 1-5) will get this response.
+   * @param buf Pointer to data that is sent
+   * @param len Length of the data to send, up to 32 bytes max.  Not affected
+   * by the static payload set by setPayloadSize().
+   */
+  void writeAckPayload(uint8_t pipe, const void* buf, uint8_t len);
+ 
+  /**
+   * Determine if an ack payload was received in the most recent call to
+   * write(). The regular available() can also be used.
+   *
+   * Call read() to retrieve the ack payload.
+   *
+   * @return True if an ack payload is available.
+   */
+  bool isAckPayloadAvailable(void);
+ 
+  /**
+   * Call this when you get an interrupt to find out why
+   *
+   * Tells you what caused the interrupt, and clears the state of
+   * interrupts.
+   *
+   * @param[out] tx_ok The send was successful (TX_DS)
+   * @param[out] tx_fail The send failed, too many retries (MAX_RT)
+   * @param[out] rx_ready There is a message waiting to be read (RX_DS)
+   */
+  void whatHappened(bool& tx_ok,bool& tx_fail,bool& rx_ready);
+ 
+  /**
+   * Non-blocking write to the open writing pipe used for buffered writes
+   *
+   * @note Optimization: This function now leaves the CE pin high, so the radio
+   * will remain in TX or STANDBY-II Mode until a txStandBy() command is issued. Can be used as an alternative to startWrite()
+   * if writing multiple payloads at once.
+   * @warning It is important to never keep the nRF24L01 in TX mode with FIFO full for more than 4ms at a time. If the auto
+   * retransmit/autoAck is enabled, the nRF24L01 is never in TX mode long enough to disobey this rule. Allow the FIFO
+   * to clear by issuing txStandBy() or ensure appropriate time between transmissions.
+   *
+   * @see write()
+   * @see writeFast()
+   * @see startWrite()
+   * @see writeBlocking()
+   *
+   * For single noAck writes see:
+   * @see enableDynamicAck()
+   * @see setAutoAck()
+   *
+   * @param buf Pointer to the data to be sent
+   * @param len Number of bytes to be sent
+   * @param multicast Request ACK (0) or NOACK (1)
+   * @return True if the payload was delivered successfully false if not
+   */
+  void startFastWrite( const void* buf, uint8_t len, const bool multicast, bool startTx = 1 );
+ 
+  /**
+   * Non-blocking write to the open writing pipe
+   *
+   * Just like write(), but it returns immediately. To find out what happened
+   * to the send, catch the IRQ and then call whatHappened().
+   *
+   * @see write()
+   * @see writeFast()
+   * @see startFastWrite()
+   * @see whatHappened()
+   *
+   * For single noAck writes see:
+   * @see enableDynamicAck()
+   * @see setAutoAck()
+   *
+   * @param buf Pointer to the data to be sent
+   * @param len Number of bytes to be sent
+   * @param multicast Request ACK (0) or NOACK (1)
+   *
+   */
+  void startWrite( const void* buf, uint8_t len, const bool multicast );
+  
+  /**
+   * This function is mainly used internally to take advantage of the auto payload
+   * re-use functionality of the chip, but can be beneficial to users as well.
+   *
+   * The function will instruct the radio to re-use the data in the FIFO buffers,
+   * and instructs the radio to re-send once the timeout limit has been reached.
+   * Used by writeFast and writeBlocking to initiate retries when a TX failure
+   * occurs. Retries are automatically initiated except with the standard write().
+   * This way, data is not flushed from the buffer until switching between modes.
+   *
+   * @note This is to be used AFTER auto-retry fails if wanting to resend
+   * using the built-in payload reuse features.
+   * After issuing reUseTX(), it will keep reending the same payload forever or until
+   * a payload is written to the FIFO, or a flush_tx command is given.
+   */
+   void reUseTX();
+ 
+  /**
+   * Empty the transmit buffer. This is generally not required in standard operation.
+   * May be required in specific cases after stopListening() , if operating at 250KBPS data rate.
+   *
+   * @return Current value of status register
+   */
+  uint8_t flush_tx(void);
+ 
+  /**
+   * Test whether there was a carrier on the line for the
+   * previous listening period.
+   *
+   * Useful to check for interference on the current channel.
+   *
+   * @return true if was carrier, false if not
+   */
+  bool testCarrier(void);
+ 
+  /**
+   * Test whether a signal (carrier or otherwise) greater than
+   * or equal to -64dBm is present on the channel. Valid only
+   * on nRF24L01P (+) hardware. On nRF24L01, use testCarrier().
+   *
+   * Useful to check for interference on the current channel and
+   * channel hopping strategies.
+   *
+   * @code
+   * bool goodSignal = radio.testRPD();
+   * if(radio.available()){
+   *    Serial.println(goodSignal ? "Strong signal > 64dBm" : "Weak signal < 64dBm" );
+   *    radio.read(0,0);
+   * }
+   * @endcode
+   * @return true if signal => -64dBm, false if not
+   */
+  bool testRPD(void) ;
+ 
+  /**
+   * Test whether this is a real radio, or a mock shim for
+   * debugging.  Setting either pin to 0xff is the way to
+   * indicate that this is not a real radio.
+   *
+   * @return true if this is a legitimate radio
+   */
+  bool isValid() { return ce_pin != 0xff && csn_pin != 0xff; }
+  
+   /**
+   * Close a pipe after it has been previously opened.
+   * Can be safely called without having previously opened a pipe.
+   * @param pipe Which pipe # to close, 0-5.
+   */
+  void closeReadingPipe( uint8_t pipe ) ;
+ 
+   /**
+   * Enable error detection by un-commenting #define FAILURE_HANDLING in RF24_config.h
+   * If a failure has been detected, it usually indicates a hardware issue. By default the library
+   * will cease operation when a failure is detected.  
+   * This should allow advanced users to detect and resolve intermittent hardware issues.  
+   *   
+   * In most cases, the radio must be re-enabled via radio.begin(); and the appropriate settings
+   * applied after a failure occurs, if wanting to re-enable the device immediately.
+   * 
+   * Usage: (Failure handling must be enabled per above)
+   *  @code
+   *  if(radio.failureDetected){ 
+   *    radio.begin();                       // Attempt to re-configure the radio with defaults
+   *    radio.failureDetected = 0;           // Reset the detection value
+   *    radio.openWritingPipe(addresses[1]); // Re-configure pipe addresses
+   *    radio.openReadingPipe(1,addresses[0]);
+   *    report_failure();                    // Blink leds, send a message, etc. to indicate failure
+   *  }
+   * @endcode
+  */
+  //#if defined (FAILURE_HANDLING)
+    bool failureDetected; 
+  //#endif
+    
+  /**@}*/
+ 
+  /**@}*/
+  /**
+   * @name Optional Configurators
+   *
+   *  Methods you can use to get or set the configuration of the chip.
+   *  None are required.  Calling begin() sets up a reasonable set of
+   *  defaults.
+   */
+  /**@{*/
+ 
+  /**
+  * Set the address width from 3 to 5 bytes (24, 32 or 40 bit)
+  *
+  * @param a_width The address width to use: 3,4 or 5
+  */
+ 
+  void setAddressWidth(uint8_t a_width);
+  
+  /**
+   * Set the number and delay of retries upon failed submit
+   *
+   * @param delay How long to wait between each retry, in multiples of 250us,
+   * max is 15.  0 means 250us, 15 means 4000us.
+   * @param count How many retries before giving up, max 15
+   */
+  void setRetries(uint8_t delay, uint8_t count);
+ 
+  /**
+   * Set RF communication channel
+   *
+   * @param channel Which RF channel to communicate on, 0-125
+   */
+  void setChannel(uint8_t channel);
+  
+    /**
+   * Get RF communication channel
+   *
+   * @return The currently configured RF Channel
+   */
+  uint8_t getChannel(void);
+ 
+  /**
+   * Set Static Payload Size
+   *
+   * This implementation uses a pre-stablished fixed payload size for all
+   * transmissions.  If this method is never called, the driver will always
+   * transmit the maximum payload size (32 bytes), no matter how much
+   * was sent to write().
+   *
+   * @todo Implement variable-sized payloads feature
+   *
+   * @param size The number of bytes in the payload
+   */
+  void setPayloadSize(uint8_t size);
+ 
+  /**
+   * Get Static Payload Size
+   *
+   * @see setPayloadSize()
+   *
+   * @return The number of bytes in the payload
+   */
+  uint8_t getPayloadSize(void);
+ 
+  /**
+   * Get Dynamic Payload Size
+   *
+   * For dynamic payloads, this pulls the size of the payload off
+   * the chip
+   *
+   * @note Corrupt packets are now detected and flushed per the
+   * manufacturer.
+   * @code
+   * if(radio.available()){
+   *   if(radio.getDynamicPayloadSize() < 1){
+   *     // Corrupt payload has been flushed
+   *     return; 
+   *   }
+   *   radio.read(&data,sizeof(data));
+   * }
+   * @endcode
+   *
+   * @return Payload length of last-received dynamic payload
+   */
+  uint8_t getDynamicPayloadSize(void);
+ 
+  /**
+   * Enable custom payloads on the acknowledge packets
+   *
+   * Ack payloads are a handy way to return data back to senders without
+   * manually changing the radio modes on both units.
+   *
+   * @note Ack payloads are dynamic payloads. This only works on pipes 0&1 by default. Call 
+   * enableDynamicPayloads() to enable on all pipes.
+   */
+  void enableAckPayload(void);
+ 
+  /**
+   * Enable dynamically-sized payloads
+   *
+   * This way you don't always have to send large packets just to send them
+   * once in a while.  This enables dynamic payloads on ALL pipes.
+   *
+   */
+  void enableDynamicPayloads(void);
+  
+  /**
+   * Enable dynamic ACKs (single write multicast or unicast) for chosen messages
+   *
+   * @note To enable full multicast or per-pipe multicast, use setAutoAck()
+   *
+   * @warning This MUST be called prior to attempting single write NOACK calls
+   * @code
+   * radio.enableDynamicAck();
+   * radio.write(&data,32,1);  // Sends a payload with no acknowledgement requested
+   * radio.write(&data,32,0);  // Sends a payload using auto-retry/autoACK
+   * @endcode
+   */
+  void enableDynamicAck();
+  
+  /**
+   * Determine whether the hardware is an nRF24L01+ or not.
+   *
+   * @return true if the hardware is nRF24L01+ (or compatible) and false
+   * if its not.
+   */
+  bool isPVariant(void) ;
+ 
+  /**
+   * Enable or disable auto-acknowlede packets
+   *
+   * This is enabled by default, so it's only needed if you want to turn
+   * it off for some reason.
+   *
+   * @param enable Whether to enable (true) or disable (false) auto-acks
+   */
+  void setAutoAck(bool enable);
+ 
+  /**
+   * Enable or disable auto-acknowlede packets on a per pipeline basis.
+   *
+   * AA is enabled by default, so it's only needed if you want to turn
+   * it off/on for some reason on a per pipeline basis.
+   *
+   * @param pipe Which pipeline to modify
+   * @param enable Whether to enable (true) or disable (false) auto-acks
+   */
+  void setAutoAck( uint8_t pipe, bool enable ) ;
+ 
+  /**
+   * Set Power Amplifier (PA) level to one of four levels:
+   * RF24_PA_MIN, RF24_PA_LOW, RF24_PA_HIGH and RF24_PA_MAX
+   *
+   * The power levels correspond to the following output levels respectively:
+   * NRF24L01: -18dBm, -12dBm,-6dBM, and 0dBm
+   *
+   * SI24R1: -6dBm, 0dBm, 3dBM, and 7dBm.
+   *
+   * @param level Desired PA level.
+   */
+  void setPALevel ( uint8_t level );
+ 
+  /**
+   * Fetches the current PA level.
+   *
+   * NRF24L01: -18dBm, -12dBm, -6dBm and 0dBm
+   * SI24R1:   -6dBm, 0dBm, 3dBm, 7dBm
+   *
+   * @return Returns values 0 to 3 representing the PA Level.
+   */
+   uint8_t getPALevel( void );
+ 
+  /**
+   * Set the transmission data rate
+   *
+   * @warning setting RF24_250KBPS will fail for non-plus units
+   *
+   * @param speed RF24_250KBPS for 250kbs, RF24_1MBPS for 1Mbps, or RF24_2MBPS for 2Mbps
+   * @return true if the change was successful
+   */
+  bool setDataRate(rf24_datarate_e speed);
+ 
+  /**
+   * Fetches the transmission data rate
+   *
+   * @return Returns the hardware's currently configured datarate. The value
+   * is one of 250kbs, RF24_1MBPS for 1Mbps, or RF24_2MBPS, as defined in the
+   * rf24_datarate_e enum.
+   */
+  rf24_datarate_e getDataRate( void ) ;
+ 
+  /**
+   * Set the CRC length
+   * <br>CRC checking cannot be disabled if auto-ack is enabled
+   * @param length RF24_CRC_8 for 8-bit or RF24_CRC_16 for 16-bit
+   */
+  void setCRCLength(rf24_crclength_e length);
+ 
+  /**
+   * Get the CRC length
+   * <br>CRC checking cannot be disabled if auto-ack is enabled
+   * @return RF24_DISABLED if disabled or RF24_CRC_8 for 8-bit or RF24_CRC_16 for 16-bit
+   */
+  rf24_crclength_e getCRCLength(void);
+ 
+  /**
+   * Disable CRC validation
+   * 
+   * @warning CRC cannot be disabled if auto-ack/ESB is enabled.
+   */
+  void disableCRC( void ) ;
+ 
+  /**
+  * The radio will generate interrupt signals when a transmission is complete,
+  * a transmission fails, or a payload is received. This allows users to mask
+  * those interrupts to prevent them from generating a signal on the interrupt
+  * pin. Interrupts are enabled on the radio chip by default.
+  *
+  * @code
+  *     Mask all interrupts except the receive interrupt:
+  *
+  *     radio.maskIRQ(1,1,0);
+  * @endcode
+  *
+  * @param tx_ok  Mask transmission complete interrupts
+  * @param tx_fail  Mask transmit failure interrupts
+  * @param rx_ready Mask payload received interrupts
+  */
+  void maskIRQ(bool tx_ok,bool tx_fail,bool rx_ready);
+  
+  /**@}*/
+  /**
+   * @name Deprecated
+   *
+   *  Methods provided for backwards compabibility.
+   */
+  /**@{*/
+ 
+ 
+  /**
+   * Open a pipe for reading
+   * @note For compatibility with old code only, see new function
+   *
+   * @warning Pipes 1-5 should share the first 32 bits.
+   * Only the least significant byte should be unique, e.g.
+   * @code
+   *   openReadingPipe(1,0xF0F0F0F0AA);
+   *   openReadingPipe(2,0xF0F0F0F066);
+   * @endcode
+   *
+   * @warning Pipe 0 is also used by the writing pipe.  So if you open
+   * pipe 0 for reading, and then startListening(), it will overwrite the
+   * writing pipe.  Ergo, do an openWritingPipe() again before write().
+   *
+   * @param number Which pipe# to open, 0-5.
+   * @param address The 40-bit address of the pipe to open.
+   */
+  void openReadingPipe(uint8_t number, uint64_t address);
+ 
+  /**
+   * Open a pipe for writing
+   * @note For compatibility with old code only, see new function
+   *
+   * Addresses are 40-bit hex values, e.g.:
+   *
+   * @code
+   *   openWritingPipe(0xF0F0F0F0F0);
+   * @endcode
+   *
+   * @param address The 40-bit address of the pipe to open.
+   */
+  void openWritingPipe(uint64_t address);
+ 
+private:
+ 
+  /**
+   * @name Low-level internal interface.
+   *
+   *  Protected methods that address the chip directly.  Regular users cannot
+   *  ever call these.  They are documented for completeness and for developers who
+   *  may want to extend this class.
+   */
+  /**@{*/
+ 
+  /**
+   * Set chip select pin
+   *
+   * Running SPI bus at PI_CLOCK_DIV2 so we don't waste time transferring data
+   * and best of all, we make use of the radio's FIFO buffers. A lower speed
+   * means we're less likely to effectively leverage our FIFOs and pay a higher
+   * AVR runtime cost as toll.
+   *
+   * @param mode HIGH to take this unit off the SPI bus, LOW to put it on
+   */
+  void csn(bool mode);
+ 
+  /**
+   * Set chip enable
+   *
+   * @param level HIGH to actively begin transmission or LOW to put in standby.  Please see data sheet
+   * for a much more detailed description of this pin.
+   */
+  void ce(bool level);
+ 
+  /**
+   * Read a chunk of data in from a register
+   *
+   * @param reg Which register. Use constants from nRF24L01.h
+   * @param buf Where to put the data
+   * @param len How many bytes of data to transfer
+   * @return Current value of status register
+   */
+  uint8_t read_register(uint8_t reg, uint8_t* buf, uint8_t len);
+ 
+  /**
+   * Read single byte from a register
+   *
+   * @param reg Which register. Use constants from nRF24L01.h
+   * @return Current value of register @p reg
+   */
+  uint8_t read_register(uint8_t reg);
+ 
+  /**
+   * Write a chunk of data to a register
+   *
+   * @param reg Which register. Use constants from nRF24L01.h
+   * @param buf Where to get the data
+   * @param len How many bytes of data to transfer
+   * @return Current value of status register
+   */
+  uint8_t write_register(uint8_t reg, const uint8_t* buf, uint8_t len);
+ 
+  /**
+   * Write a single byte to a register
+   *
+   * @param reg Which register. Use constants from nRF24L01.h
+   * @param value The new value to write
+   * @return Current value of status register
+   */
+  uint8_t write_register(uint8_t reg, uint8_t value);
+ 
+  /**
+   * Write the transmit payload
+   *
+   * The size of data written is the fixed payload size, see getPayloadSize()
+   *
+   * @param buf Where to get the data
+   * @param len Number of bytes to be sent
+   * @return Current value of status register
+   */
+  uint8_t write_payload(const void* buf, uint8_t len, const uint8_t writeType);
+ 
+  /**
+   * Read the receive payload
+   *
+   * The size of data read is the fixed payload size, see getPayloadSize()
+   *
+   * @param buf Where to put the data
+   * @param len Maximum number of bytes to read
+   * @return Current value of status register
+   */
+  uint8_t read_payload(void* buf, uint8_t len);
+ 
+  /**
+   * Empty the receive buffer
+   *
+   * @return Current value of status register
+   */
+  uint8_t flush_rx(void);
+ 
+  /**
+   * Retrieve the current status of the chip
+   *
+   * @return Current value of status register
+   */
+  uint8_t get_status(void);
+ 
+  #if !defined (MINIMAL)
+  /**
+   * Decode and print the given status to stdout
+   *
+   * @param status Status value to print
+   *
+   * @warning Does nothing if stdout is not defined.  See fdevopen in stdio.h
+   */
+  void print_status(uint8_t status);
+ 
+  /**
+   * Decode and print the given 'observe_tx' value to stdout
+   *
+   * @param value The observe_tx value to print
+   *
+   * @warning Does nothing if stdout is not defined.  See fdevopen in stdio.h
+   */
+  void print_observe_tx(uint8_t value);
+ 
+  /**
+   * Print the name and value of an 8-bit register to stdout
+   *
+   * Optionally it can print some quantity of successive
+   * registers on the same line.  This is useful for printing a group
+   * of related registers on one line.
+   *
+   * @param name Name of the register
+   * @param reg Which register. Use constants from nRF24L01.h
+   * @param qty How many successive registers to print
+   */
+  void print_byte_register(const char* name, uint8_t reg, uint8_t qty = 1);
+ 
+  /**
+   * Print the name and value of a 40-bit address register to stdout
+   *
+   * Optionally it can print some quantity of successive
+   * registers on the same line.  This is useful for printing a group
+   * of related registers on one line.
+   *
+   * @param name Name of the register
+   * @param reg Which register. Use constants from nRF24L01.h
+   * @param qty How many successive registers to print
+   */
+  void print_address_register(const char* name, uint8_t reg, uint8_t qty = 1);
+#endif
+  /**
+   * Turn on or off the special features of the chip
+   *
+   * The chip has certain 'features' which are only available when the 'features'
+   * are enabled.  See the datasheet for details.
+   */
+  void toggle_features(void);
+ 
+  /**
+   * Built in spi transfer function to simplify repeating code repeating code
+   */
+ 
+  uint8_t spiTrans(uint8_t cmd);
+  
+  #if defined (FAILURE_HANDLING) || defined (RF24_LINUX)
+    void errNotify(void);
+  #endif
+  
+  /**@}*/
+ 
+};
+ 
+ 
+/**
+ * @example GettingStarted.ino
+ * <b>For Arduino</b><br>
+ * <b>Updated: TMRh20 2014 </b><br>
+ *
+ * This is an example of how to use the RF24 class to communicate on a basic level. Configure and write this sketch to two
+ * different nodes. Put one of the nodes into 'transmit' mode by connecting with the serial monitor and <br>
+ * sending a 'T'. The ping node sends the current time to the pong node, which responds by sending the value
+ * back. The ping node can then see how long the whole cycle took. <br>
+ * @note For a more efficient call-response scenario see the GettingStarted_CallResponse.ino example.
+ * @note When switching between sketches, the radio may need to be powered down to clear settings that are not "un-set" otherwise
+ */
+ 
+ /**
+ * @example GettingStarted.cpp
+ * <b>For Raspberry Pi</b><br>
+ * <b>Updated: TMRh20 2014 </b><br>
+ *
+ * This is an example of how to use the RF24 class to communicate on a basic level. Configure and write this sketch to two
+ * different nodes. Put one of the nodes into 'transmit' mode by connecting with the serial monitor and <br>
+ * sending a 'T'. The ping node sends the current time to the pong node, which responds by sending the value
+ * back. The ping node can then see how long the whole cycle took. <br>
+ * @note For a more efficient call-response scenario see the GettingStarted_CallResponse.ino example.
+ */
+ 
+/**
+ * @example GettingStarted_CallResponse.ino
+ * <b>For Arduino</b><br>
+ * <b>New: TMRh20 2014</b><br>
+ *
+ * This example continues to make use of all the normal functionality of the radios including
+ * the auto-ack and auto-retry features, but allows ack-payloads to be written optionlly as well. <br>
+ * This allows very fast call-response communication, with the responding radio never having to
+ * switch out of Primary Receiver mode to send back a payload, but having the option to switch to <br>
+ * primary transmitter if wanting to initiate communication instead of respond to a commmunication.
+ */
+ 
+ /**
+ * @example GettingStarted_Call_Response.cpp
+ * <b>For Raspberry Pi</b><br>
+ * <b>New: TMRh20 2014</b><br>
+ *
+ * This example continues to make use of all the normal functionality of the radios including
+ * the auto-ack and auto-retry features, but allows ack-payloads to be written optionlly as well. <br>
+ * This allows very fast call-response communication, with the responding radio never having to
+ * switch out of Primary Receiver mode to send back a payload, but having the option to switch to <br>
+ * primary transmitter if wanting to initiate communication instead of respond to a commmunication.
+ */
+ 
+ /**
+ * @example GettingStarted_HandlingData.ino
+ * <b>Dec 2014 - TMRh20</b><br>
+ *
+ * This example demonstrates how to send multiple variables in a single payload and work with data. As usual, it is
+ * generally important to include an incrementing value like millis() in the payloads to prevent errors.
+ */
+ 
+/**
+ * @example Transfer.ino
+ * <b>For Arduino</b><br>
+ * This example demonstrates half-rate transfer using the FIFO buffers<br>
+ *
+ * It is an example of how to use the RF24 class.  Write this sketch to two
+ * different nodes.  Put one of the nodes into 'transmit' mode by connecting <br>
+ * with the serial monitor and sending a 'T'.  The data transfer will begin,
+ * with the receiver displaying the payload count. (32Byte Payloads) <br>
+ */
+ 
+ /**
+ * @example Transfer.cpp
+ * <b>For Raspberry Pi</b><br>
+ * This example demonstrates half-rate transfer using the FIFO buffers<br>
+ *
+ * It is an example of how to use the RF24 class.  Write this sketch to two
+ * different nodes.  Put one of the nodes into 'transmit' mode by connecting <br>
+ * with the serial monitor and sending a 'T'.  The data transfer will begin,
+ * with the receiver displaying the payload count. (32Byte Payloads) <br>
+ */
+ 
+/**
+ * @example TransferTimeouts.ino
+ * <b>New: TMRh20 </b><br>
+ * This example demonstrates the use of and extended timeout period and
+ * auto-retries/auto-reUse to increase reliability in noisy or low signal scenarios. <br>
+ *
+ * Write this sketch to two different nodes.  Put one of the nodes into 'transmit'
+ * mode by connecting with the serial monitor and sending a 'T'.  The data <br>
+ * transfer will begin, with the receiver displaying the payload count and the
+ * data transfer rate.
+ */
+ 
+/**
+ * @example starping.pde
+ *
+ * This sketch is a more complex example of using the RF24 library for Arduino.
+ * Deploy this on up to six nodes.  Set one as the 'pong receiver' by tying the
+ * role_pin low, and the others will be 'ping transmit' units.  The ping units
+ * unit will send out the value of millis() once a second.  The pong unit will
+ * respond back with a copy of the value.  Each ping unit can get that response
+ * back, and determine how long the whole cycle took.
+ *
+ * This example requires a bit more complexity to determine which unit is which.
+ * The pong receiver is identified by having its role_pin tied to ground.
+ * The ping senders are further differentiated by a byte in eeprom.
+ */
+ 
+/**
+ * @example pingpair_ack.ino
+ * <b>Update: TMRh20</b><br>
+ * This example continues to make use of all the normal functionality of the radios including
+ * the auto-ack and auto-retry features, but allows ack-payloads to be written optionlly as well.<br>
+ * This allows very fast call-response communication, with the responding radio never having to
+ * switch out of Primary Receiver mode to send back a payload, but having the option to if wanting<br>
+ * to initiate communication instead of respond to a commmunication.
+ */
+ 
+/**
+ * @example pingpair_irq.ino
+ * <b>Update: TMRh20</b><br>
+ * This is an example of how to user interrupts to interact with the radio, and a demonstration
+ * of how to use them to sleep when receiving, and not miss any payloads.<br>
+ * The pingpair_sleepy example expands on sleep functionality with a timed sleep option for the transmitter.
+ * Sleep functionality is built directly into my fork of the RF24Network library<br>
+ */
+ 
+ /**
+ * @example pingpair_irq_simple.ino
+ * <b>Dec 2014 - TMRh20</b><br>
+ * This is an example of how to user interrupts to interact with the radio, with bidirectional communication.
+ */
+ 
+/**
+ * @example pingpair_sleepy.ino
+ * <b>Update: TMRh20</b><br>
+ * This is an example of how to use the RF24 class to create a battery-
+ * efficient system.  It is just like the GettingStarted_CallResponse example, but the<br>
+ * ping node powers down the radio and sleeps the MCU after every
+ * ping/pong cycle, and the receiver sleeps between payloads. <br>
+ */
+ 
+ /**
+ * @example rf24ping85.ino
+ * <b>New: Contributed by https://github.com/tong67</b><br>
+ * This is an example of how to use the RF24 class to communicate with ATtiny85 and other node. <br>
+ */
+ 
+ /**
+ * @example timingSearch3pin.ino
+ * <b>New: Contributed by https://github.com/tong67</b><br>
+ * This is an example of how to determine the correct timing for ATtiny when using only 3-pins
+ */
+  
+/**
+ * @example pingpair_dyn.ino
+ *
+ * This is an example of how to use payloads of a varying (dynamic) size on Arduino.
+ */
+ 
+ /**
+ * @example pingpair_dyn.cpp
+ *
+ * This is an example of how to use payloads of a varying (dynamic) size on Raspberry Pi.
+ */
+ 
+/**
+ * @example pingpair_dyn.py
+ *
+ * This is a python example for RPi of how to use payloads of a varying (dynamic) size.
+ */ 
+ 
+/**
+ * @example pingpair_dyn.ino
+ *
+ * This is an example of how to use payloads of a varying (dynamic) size.
+ */
+ 
+ /**
+ * @example pingpair_dyn.ino
+ *
+ * This is an example of how to use payloads of a varying (dynamic) size.
+ */
+ 
+/**
+ * @example scanner.ino
+ *
+ * Example to detect interference on the various channels available.
+ * This is a good diagnostic tool to check whether you're picking a
+ * good channel for your application.
+ *
+ * Inspired by cpixip.
+ * See http://arduino.cc/forum/index.php/topic,54795.0.html
+ */
+ 
+/**
+ * @mainpage Optimized High Speed Driver for nRF24L01(+) 2.4GHz Wireless Transceiver
+ *
+ * @section Goals Design Goals
+ *
+ * This library fork is designed to be...
+ * @li More compliant with the manufacturer specified operation of the chip, while allowing advanced users
+ * to work outside the recommended operation.
+ * @li Utilize the capabilities of the radio to their full potential via Arduino
+ * @li More reliable, responsive, bug-free and feature rich
+ * @li Easy for beginners to use, with well documented examples and features
+ * @li Consumed with a public interface that's similar to other Arduino standard libraries
+ *
+ * @section News News
+ *
+ * **Dec 2015**<br>
+ * - ESP8266 support via Arduino IDE
+ * - <a href="https://github.com/stewarthou/Particle-RF24">Particle Photon/Core</a> fork available
+ * - ATTiny2313/4313 support added
+ * - Python 3 support added
+ * - RF24 added to Arduino library manager
+ * - RF24 added to PlatformIO library manager
+ *
+ * **March 2015**<br>
+ * - Uses SPI transactions on Arduino
+ * - New layout for <a href="Portability.html">easier portability:</a> Break out defines & includes for individual platforms to RF24/utility
+ * - <a href="MRAA.html">MRAA</a> support added ( Galileo, Edison, etc)
+ * - <a href="BBB.html">BBB/Generic Linux </a> support via spidev & MRAA
+ * - Support for RPi 2 added
+ * - Major Documentation cleanup & update (Move all docs to github.io)
+ *
+ *
+ * If issues are discovered with the documentation, please report them <a href="https://github.com/TMRh20/tmrh20.github.io/issues"> here</a>
+ *
+ * <br>
+ * @section Useful Useful References
+ *
+ *
+ * @li <a href="http://tmrh20.github.io/RF24/classRF24.html"><b>RF24</b> Class Documentation</a>
+ * @li <a href="https://github.com/TMRh20/RF24/archive/master.zip"><b>Download</b></a>
+ * @li <a href="https://github.com/tmrh20/RF24/"><b>Source Code</b></a>
+ * @li <a href="http://tmrh20.blogspot.com/2014/03/high-speed-data-transfers-and-wireless.html"><b>My Blog:</b> RF24 Optimization Overview</a> 
+ * @li <a href="http://www.nordicsemi.com/files/Product/data_sheet/nRF24L01_Product_Specification_v2_0.pdf">Chip Datasheet</a>
+ *
+ * **Additional Information and Add-ons**
+ *
+ * @li <a href="http://tmrh20.github.io/RF24Network"> <b>RF24Network:</b> OSI Network Layer for multi-device communication. Create a home sensor network.</a>
+ * @li <a href="http://tmrh20.github.io/RF24Mesh"> <b>RF24Mesh:</b> Dynamic Mesh Layer for RF24Network</a>
+ * @li <a href="http://tmrh20.github.io/RF24Ethernet"> <b>RF24Ethernet:</b> TCP/IP Radio Mesh Networking (shares Arduino Ethernet API)</a>
+ * @li <a href="http://tmrh20.github.io/RF24Audio"> <b>RF24Audio:</b> Realtime Wireless Audio streaming</a>
+ * @li <a href="http://tmrh20.github.io/">All TMRh20 Documentation Main Page</a>
+ *
+ * **More Information and RF24 Based Projects**
+ *
+ * @li <a href="http://TMRh20.blogspot.com"> Project Blog: TMRh20.blogspot.com </a>
+ * @li <a href="http://maniacalbits.blogspot.ca/"> Maniacal Bits Blog</a>
+ * @li <a href="http://www.mysensors.org/">MySensors.org (User friendly sensor networks/IoT)</a>
+ * @li <a href="https://github.com/mannkind/RF24Node_MsgProto"> RF24Node_MsgProto (MQTT)</a>
+ * @li <a href="https://bitbucket.org/pjhardy/rf24sensornet/"> RF24SensorNet </a>
+ * @li <a href="http://www.homeautomationforgeeks.com/rf24software.shtml">Home Automation for Geeks</a>
+ * @li <a href="https://maniacbug.wordpress.com/2012/03/30/rf24network/"> Original Maniacbug RF24Network Blog Post</a>
+ * @li <a href="https://github.com/maniacbug/RF24"> ManiacBug on GitHub (Original Library Author)</a>
+ * 
+ *
+ * <br>
+ *
+ * @section Platform_Support Platform Support Pages
+ *
+ * @li <a href="Arduino.html"><b>Arduino</b></a> (Uno, Nano, Mega, Due, Galileo, etc)
+ * @li <a href="ATTiny.html"><b>ATTiny</b></a>
+ * @li Linux ( <a href="RPi.html"><b>RPi</b></a> , <a href="BBB.html"><b>BBB</b></a>, <a href="MRAA.html"><b>MRAA</b></a> supported boards ( Galileo, Edison, etc))
+ * @li <a href="Python.html"><b>Python</b></a> wrapper available for RPi
+ *
+ * <br>
+ * **General µC Pin layout** (See the individual board support pages for more info)
+ *
+ * The table below shows how to connect the the pins of the NRF24L01(+) to different boards.
+ * CE and CSN are configurable.
+ *
+ * | PIN | NRF24L01 | Arduino UNO | ATtiny25/45/85 [0] | ATtiny44/84 [1] | LittleWire [2]          |    RPI     | RPi -P1 Connector |
+ * |-----|----------|-------------|--------------------|-----------------|-------------------------|------------|-------------------|
+ * |  1  |   GND    |   GND       |     pin 4          |    pin 14       | GND                     | rpi-gnd    |     (25)          |
+ * |  2  |   VCC    |   3.3V      |     pin 8          |    pin  1       | regulator 3.3V required | rpi-3v3    |     (17)          |
+ * |  3  |   CE     |   digIO 7   |     pin 2          |    pin 12       | pin to 3.3V             | rpi-gpio22 |     (15)          |
+ * |  4  |   CSN    |   digIO 8   |     pin 3          |    pin 11       | RESET                   | rpi-gpio8  |     (24)          |
+ * |  5  |   SCK    |   digIO 13  |     pin 7          |    pin  9       | SCK                     | rpi-sckl   |     (23)          |
+ * |  6  |   MOSI   |   digIO 11  |     pin 6          |    pin  7       | MOSI                    | rpi-mosi   |     (19)          |
+ * |  7  |   MISO   |   digIO 12  |     pin 5          |    pin  8       | MISO                    | rpi-miso   |     (21)          |
+ * |  8  |   IRQ    |      -      |        -           |         -       | -                       |    -       |       -           |
+ *
+ * @li [0] https://learn.sparkfun.com/tutorials/tiny-avr-programmer-hookup-guide/attiny85-use-hints
+ * @li [1] http://highlowtech.org/?p=1695
+ * @li [2] http://littlewire.cc/   
+ * <br><br><br>
+ *
+ *
+ *
+ *
+ * @page Arduino Arduino
+ * 
+ * RF24 is fully compatible with Arduino boards <br>
+ * See <b> http://www.arduino.cc/en/Reference/Board </b> and <b> http://arduino.cc/en/Reference/SPI </b> for more information
+ * 
+ * RF24 makes use of the standard hardware SPI pins (MISO,MOSI,SCK) and requires two additional pins, to control
+ * the chip-select and chip-enable functions.<br>
+ * These pins must be chosen and designated by the user, in RF24 radio(ce_pin,cs_pin); and can use any 
+ * available pins.
+ * 
+ * <br>
+ * @section ARD_DUE Arduino Due
+ * 
+ * RF24 makes use of the extended SPI functionality available on the Arduino Due, and requires one of the
+ * defined hardware SS/CS pins to be designated in RF24 radio(ce_pin,cs_pin);<br>
+ * See http://arduino.cc/en/Reference/DueExtendedSPI for more information
+ *
+ * Initial Due support taken from https://github.com/mcrosson/RF24/tree/due
+ *
+ * <br>
+ * @section Alternate_SPI Alternate SPI Support
+ *
+ * RF24 supports alternate SPI methods, in case the standard hardware SPI pins are otherwise unavailable.
+ * 
+ * <br>
+ * **Software Driven SPI**
+ *
+ * Software driven SPI is provided by the <a href=https://github.com/greiman/DigitalIO>DigitalIO</a> library
+ *
+ * Setup:<br>
+ * 1. Install the digitalIO library<br>
+ * 2. Open RF24_config.h in a text editor. Uncomment the line #define SOFTSPI<br>
+ * 3. In your sketch, add #include DigitalIO.h
+ *
+ * @note Note: Pins are listed as follows and can be modified by editing the RF24_config.h file<br>
+ *
+ *     const uint8_t SOFT_SPI_MISO_PIN = 16;
+ *     const uint8_t SOFT_SPI_MOSI_PIN = 15;
+ *     const uint8_t SOFT_SPI_SCK_PIN = 14;
+ *
+ * <br>
+ * **Alternate Hardware (UART) Driven  SPI**
+ *
+ * The Serial Port (UART) on Arduino can also function in SPI mode, and can double-buffer data, while the 
+ * default SPI hardware cannot.
+ *
+ * The SPI_UART library is available at https://github.com/TMRh20/Sketches/tree/master/SPI_UART
+ * 
+ * Enabling:
+ * 1. Install the SPI_UART library
+ * 2. Edit RF24_config.h and uncomment #define SPI_UART
+ * 3. In your sketch, add @code #include <SPI_UART.h> @endcode
+ *
+ * SPI_UART SPI Pin Connections:
+ * | NRF |Arduino Uno Pin|
+ * |-----|---------------|
+ * | MOSI| TX(0)         |
+ * | MISO| RX(1)         |
+ * | SCK | XCK(4)        |
+ * | CE  | User Specified|
+ * | CSN | User Specified|
+ *
+ *
+ * @note SPI_UART on Mega boards requires soldering to an unused pin on the chip. <br>See
+ * https://github.com/TMRh20/RF24/issues/24 for more information on SPI_UART.
+ * 
+ * @page ATTiny ATTiny
+ *
+ * ATTiny support is built into the library, so users are not required to include SPI.h in their sketches<br>
+ * See the included rf24ping85 example for pin info and usage
+ * 
+ * Some versions of Arduino IDE may require a patch to allow use of the full program space on ATTiny<br>
+ * See https://github.com/TCWORLD/ATTinyCore/tree/master/PCREL%20Patch%20for%20GCC for ATTiny patch
+ *
+ * ATTiny board support initially added from https://github.com/jscrane/RF24
+ *
+ * @section Hardware Hardware Configuration
+ * By tong67 ( https://github.com/tong67 )
+ * 
+ *    **ATtiny25/45/85 Pin map with CE_PIN 3 and CSN_PIN 4**
+ * @code
+ *                                 +-\/-+
+ *                   NC      PB5  1|o   |8  Vcc --- nRF24L01  VCC, pin2 --- LED --- 5V
+ *    nRF24L01  CE, pin3 --- PB3  2|    |7  PB2 --- nRF24L01  SCK, pin5
+ *    nRF24L01 CSN, pin4 --- PB4  3|    |6  PB1 --- nRF24L01 MOSI, pin6
+ *    nRF24L01 GND, pin1 --- GND  4|    |5  PB0 --- nRF24L01 MISO, pin7
+ *                                 +----+ 
+ * @endcode
+ *
+ * <br>
+ *    **ATtiny25/45/85 Pin map with CE_PIN 3 and CSN_PIN 3** => PB3 and PB4 are free to use for application <br>
+ *    Circuit idea from http://nerdralph.blogspot.ca/2014/01/nrf24l01-control-with-3-attiny85-pins.html <br>
+ *   Original RC combination was 1K/100nF. 22K/10nF combination worked better.                          <br>
+ *  For best settletime delay value in RF24::csn() the timingSearch3pin.ino sketch can be used.         <br>
+ *    This configuration is enabled when CE_PIN and CSN_PIN are equal, e.g. both 3                      <br>
+ *    Because CE is always high the power consumption is higher than for 5 pins solution                <br>
+ * @code
+ *                                                                                           ^^         
+ *                                 +-\/-+           nRF24L01   CE, pin3 ------|              //         
+ *                           PB5  1|o   |8  Vcc --- nRF24L01  VCC, pin2 ------x----------x--|<|-- 5V    
+ *                   NC      PB3  2|    |7  PB2 --- nRF24L01  SCK, pin5 --|<|---x-[22k]--|  LED         
+ *                   NC      PB4  3|    |6  PB1 --- nRF24L01 MOSI, pin6  1n4148 |                       
+ *    nRF24L01 GND, pin1 -x- GND  4|    |5  PB0 --- nRF24L01 MISO, pin7         |                       
+ *                        |        +----+                                       |                       
+ *                        |-----------------------------------------------||----x-- nRF24L01 CSN, pin4  
+ *                                                                      10nF                            
+ * @endcode
+ *
+ * <br>
+ *    **ATtiny24/44/84 Pin map with CE_PIN 8 and CSN_PIN 7** <br>
+ *  Schematic provided and successfully tested by Carmine Pastore (https://github.com/Carminepz) <br>
+ * @code
+ *                                  +-\/-+                                                              
+ *    nRF24L01  VCC, pin2 --- VCC  1|o   |14 GND --- nRF24L01  GND, pin1
+ *                            PB0  2|    |13 AREF
+ *                            PB1  3|    |12 PA1
+ *                            PB3  4|    |11 PA2 --- nRF24L01   CE, pin3
+ *                            PB2  5|    |10 PA3 --- nRF24L01  CSN, pin4
+ *                            PA7  6|    |9  PA4 --- nRF24L01  SCK, pin5
+ *    nRF24L01 MISO, pin7 --- PA6  7|    |8  PA5 --- nRF24L01 MOSI, pin6
+ *                                  +----+
+ *  @endcode                     
+ *  
+ * <br>
+ *    **ATtiny2313/4313 Pin map with CE_PIN 12 and CSN_PIN 13** <br>
+ * @code
+ *                                  +-\/-+                                                              
+ *                            PA2  1|o   |20 VCC --- nRF24L01  VCC, pin2
+ *                            PD0  2|    |19 PB7 --- nRF24L01  SCK, pin5
+ *                            PD1  3|    |18 PB6 --- nRF24L01 MOSI, pin6
+ *                            PA1  4|    |17 PB5 --- nRF24L01 MISO, pin7
+ *                            PA0  5|    |16 PB4 --- nRF24L01  CSN, pin4
+ *                            PD2  6|    |15 PB3 --- nRF24L01   CE, pin3
+ *                            PD3  7|    |14 PB2
+ *                            PD4  8|    |13 PB1
+ *                            PD5  9|    |12 PB0
+ *    nRF24L01  GND, pin1 --- GND 10|    |11 PD6
+ *                                  +----+
+ *  @endcode                     
+ *
+ * <br><br><br>
+ *
+ *
+ * 
+ * 
+ *
+ *
+ * @page BBB BeagleBone Black
+ *
+ * BeagleBone Black is supported via MRAA or SPIDEV.
+ *
+ *  @note The SPIDEV option should work with most Linux systems supporting SPIDEV. <br>
+ *  Users may need to edit the RF24/utility/BBB/spi.cpp file to configure the spi device. (Defaults: "/dev/spidev1.0";  or  "/dev/spidev1.1"; )
+ *
+ * <br>
+ * @section AutoInstall Automated Install 
+ *(**Designed & Tested on RPi** - Defaults to SPIDEV on BBB)
+ *
+ * 
+ * 1. Download the install.sh file from http://tmrh20.github.io/RF24Installer/RPi/install.sh
+ * @code wget http://tmrh20.github.io/RF24Installer/RPi/install.sh @endcode
+ * 2. Make it executable:
+ * @code chmod +x install.sh @endcode
+ * 3. Run it and choose your options
+ * @code ./install.sh @endcode
+ * 4. Run an example from one of the libraries
+ * @code 
+ * cd rf24libs/RF24/examples_RPi  
+ * @endcode
+ * Edit the gettingstarted example, to set your pin configuration
+ * @code nano gettingstarted.cpp
+ * make  
+ * sudo ./gettingstarted  
+ * @endcode
+ *
+ * <br>
+ * @section ManInstall Manual Install
+ * 1. Make a directory to contain the RF24 and possibly RF24Network lib and enter it: 
+ * @code
+ *  mkdir ~/rf24libs 
+ *  cd ~/rf24libs
+*  @endcode
+ * 2. Clone the RF24 repo:
+ *    @code git clone https://github.com/tmrh20/RF24.git RF24 @endcode
+ * 3. Change to the new RF24 directory
+ *    @code cd RF24 @endcode
+ * 4. Build the library, and run an example file: 
+ * **Note:** See the <a href="http://iotdk.intel.com/docs/master/mraa/index.html">MRAA </a> documentation for more info on installing MRAA
+ *    @code sudo make install  OR  sudo make install RF24_MRAA=1 @endcode
+ * @code
+ * cd examples_RPi  
+ * @endcode
+ * Edit the gettingstarted example, to set your pin configuration
+ * @code nano gettingstarted.cpp 
+ * make 
+ * sudo ./gettingstarted
+ * @endcode
+ *
+ * <br><br>
+ *   
+ * @page MRAA MRAA
+ *  
+ * MRAA is a Low Level Skeleton Library for Communication on GNU/Linux platforms <br>
+ * See http://iotdk.intel.com/docs/master/mraa/index.html for more information
+ *
+ * RF24 supports all MRAA supported platforms, but might not be tested on each individual platform due to the wide range of hardware support:<br>
+ * <a href="https://github.com/TMRh20/RF24/issues">Report an RF24 bug or issue </a>
+ *
+ * @section Setup Setup
+ * 1. Install the MRAA lib
+ * 2. As per your device, SPI may need to be enabled
+ * 
+ * @section MRAA_Install Install 
+ *
+ * 1. Make a directory to contain the RF24 and possibly RF24Network lib and enter it: 
+ * @code
+ *  mkdir ~/rf24libs 
+ *  cd ~/rf24libs
+*  @endcode
+ * 2. Clone the RF24 repo:
+ *    @code git clone https://github.com/tmrh20/RF24.git RF24 @endcode
+ * 3. Change to the new RF24 directory
+ *    @code cd RF24 @endcode
+ * 4. Build the library: 
+ *    @code sudo make install -B RF24_MRAA=1 @endcode
+ * 5. Configure the correct pins in gettingstarted.cpp (See http://iotdk.intel.com/docs/master/mraa/index.html )
+ *    @code
+ *    cd examples_RPi  
+ *    nano gettingstarted.cpp 
+ *    @endcode
+ * 6. Build an example
+ *    @code
+ *    make  
+ *    sudo ./gettingstarted
+ *    @endcode
+ *
+ * <br><br><br>
+ *
+ * 
+ *
+ *
+ * @page RPi Raspberry Pi
+ *
+ * RF24 supports a variety of Linux based devices via various drivers. Some boards like RPi can utilize multiple methods
+ * to drive the GPIO and SPI functionality.
+ *
+ * <br>
+ * @section PreConfig Potential PreConfiguration
+ *
+ * If SPI is not already enabled, load it on boot:
+ * @code sudo raspi-config  @endcode
+ * A. Update the tool via the menu as required<br>
+ * B. Select **Advanced** and **enable the SPI kernel module** <br>
+ * C. Update other software and libraries:
+ * @code sudo apt-get update @endcode
+ * @code sudo apt-get upgrade @endcode 
+ * <br>
+ * @section AutoInstall Automated Install
+ *
+ * 1. Download the install.sh file from http://tmrh20.github.io/RF24Installer/RPi/install.sh
+ * @code wget http://tmrh20.github.io/RF24Installer/RPi/install.sh @endcode
+ * 2. Make it executable:
+ * @code chmod +x install.sh @endcode
+ * 3. Run it and choose your options
+ * @code ./install.sh @endcode
+ * 4. Run an example from one of the libraries
+ * @code 
+ * cd rf24libs/RF24/examples_RPi  
+ * make  
+ * sudo ./gettingstarted  
+ * @endcode
+ * <br><br>
+ * @section ManInstall Manual Install
+ * 1. Make a directory to contain the RF24 and possibly RF24Network lib and enter it: 
+ * @code
+ *  mkdir ~/rf24libs 
+ *  cd ~/rf24libs
+*  @endcode
+ * 2. Clone the RF24 repo:
+ *    @code git clone https://github.com/tmrh20/RF24.git RF24 @endcode
+ * 3. Change to the new RF24 directory
+ *    @code cd RF24 @endcode
+ * 4. Build the library, and run an example file: 
+ * @code sudo make install
+ * cd examples_RPi  
+ * make  
+ * sudo ./gettingstarted
+ * @endcode
+ *
+ * <br><br>
+ * @section Build Build Options
+ * The default build on Raspberry Pi utilizes the included **BCM2835** driver from http://www.airspayce.com/mikem/bcm2835
+ * 1. @code sudo make install -B @endcode
+ *
+ * Build using the **MRAA** library from http://iotdk.intel.com/docs/master/mraa/index.html <br>
+ * MRAA is not included. See the <a href="MRAA.html">MRAA</a> platform page for more information.
+ *
+ * 1. Install, and build MRAA:
+ * @code
+ * git clone https://github.com/intel-iot-devkit/mraa.git
+ * cd mraa
+ * mkdir build
+ * cd build
+ * cmake .. -DBUILDSWIGNODE=OFF
+ * sudo make install
+ * @endcode
+ *
+ * 2. Complete the install <br>
+ * @code nano /etc/ld.so.conf @endcode
+ * Add the line @code /usr/local/lib/arm-linux-gnueabihf @endcode
+ * Run @code sudo ldconfig @endcode
+ *
+ * 3. Install RF24, using MRAA
+ * @code sudo make install -B RF24_MRAA=1 @endcode
+ * See the gettingstarted example for an example of pin configuration
+ *
+ * Build using **spidev**:
+ *
+ * 1. Edit the RF24/utility/BBB/spi.cpp file
+ * 2. Change the default device definition to @code this->device = "/dev/spidev0.0";; @endcode
+ * 3. Run @code sudo make install -B RF24_SPIDEV=1 @endcode
+ * 4. See the gettingstarted example for an example of pin configuration
+ *
+ * <br>
+ * @section Pins Connections and Pin Configuration
+ *
+ *
+ * Using pin 15/GPIO 22 for CE, pin 24/GPIO8 (CE0) for CSN
+ *
+ * Can use either RPi CE0 or CE1 pins for radio CSN.<br>
+ * Choose any RPi output pin for radio CE pin.
+ *
+ * **BCM2835 Constructor:**
+ * @code
+ *  RF24 radio(RPI_V2_GPIO_P1_15,BCM2835_SPI_CS0, BCM2835_SPI_SPEED_8MHZ);
+ *   or
+ *  RF24 radio(RPI_V2_GPIO_P1_15,BCM2835_SPI_CS1, BCM2835_SPI_SPEED_8MHZ);
+ *  
+ *  RPi B+:
+ *  RF24 radio(RPI_BPLUS_GPIO_J8_15,RPI_BPLUS_GPIO_J8_24, BCM2835_SPI_SPEED_8MHZ);
+ *  or
+ *  RF24 radio(RPI_BPLUS_GPIO_J8_15,RPI_BPLUS_GPIO_J8_26, BCM2835_SPI_SPEED_8MHZ);
+ *
+ *  General:
+ *  RF24 radio(22,0);
+ *  or
+ *  RF24 radio(22,1);
+ *
+ * @endcode
+ * See the gettingstarted example for an example of pin configuration
+ *
+ * See http://www.airspayce.com/mikem/bcm2835/index.html for BCM2835 class documentation.
+ * <br><br>
+ * **MRAA Constructor:**
+ *
+ * @code RF24 radio(15,0); @endcode
+ *
+ * See http://iotdk.intel.com/docs/master/mraa/rasppi.html
+ * <br><br>
+ * **SPI_DEV Constructor**
+ *
+ * @code RF24 radio(22,0); @endcode
+ *
+ * See http://pi.gadgetoid.com/pinout
+ *
+ * **Pins:**  
+ *
+ * | PIN | NRF24L01 |    RPI     | RPi -P1 Connector |
+ * |-----|----------|------------|-------------------|
+ * |  1  |   GND    | rpi-gnd    |     (25)          |
+ * |  2  |   VCC    | rpi-3v3    |     (17)          |
+ * |  3  |   CE     | rpi-gpio22 |     (15)          |
+ * |  4  |   CSN    | rpi-gpio8  |     (24)          |
+ * |  5  |   SCK    | rpi-sckl   |     (23)          |
+ * |  6  |   MOSI   | rpi-mosi   |     (19)          |
+ * |  7  |   MISO   | rpi-miso   |     (21)          |
+ * |  8  |   IRQ    |    -       |       -           |
+ *   
+ *   
+ *  
+ *  
+ * <br><br>
+ ****************
+ *   
+ * Based on the arduino lib from J. Coliz <maniacbug@ymail.com>  <br>
+ * the library was berryfied by Purinda Gunasekara <purinda@gmail.com> <br>  
+ * then forked from github stanleyseow/RF24 to https://github.com/jscrane/RF24-rpi  <br>
+ * Network lib also based on https://github.com/farconada/RF24Network
+ *
+ * 
+ *
+ * 
+ * <br><br><br>
+ * 
+ *
+ *  
+ * @page Python Python Wrapper (by https://github.com/mz-fuzzy)
+ * 
+ * @section Install Installation:  
+ * 
+ * Install the boost libraries:  (Note: Only the python libraries should be needed, this is just for simplicity)
+ *
+ * @code sudo apt-get install libboost1.50-all @endcode
+ *
+ * Build the library:  
+ *
+ * @code ./setup.py build   @endcode
+ *
+ * Install the library 
+ *
+ * @code sudo ./setup.py install  @endcode
+ *
+ * 
+ * See the additional <a href="pages.html">Platform Support</a> pages for information on connecting your hardware  <br>
+ * See the included <a href="pingpair_dyn_8py-example.html">example </a> for usage information.   
+ * 
+ * Running the Example:  
+ * 
+ * Edit the pingpair_dyn.py example to configure the appropriate pins per the above documentation:  
+ *
+ * @code nano pingpair_dyn.py   @endcode
+ *
+ * Configure another device, Arduino or RPi with the <a href="pingpair_dyn_8py-example.html">pingpair_dyn</a> example  
+ *
+ * Run the example  
+ *
+ * @code sudo ./pingpair_dyn.py  @endcode
+ *
+ * <br><br><br>
+ *
+ *
+ * @page Portability RF24 Portability
+ *
+ * The RF24 radio driver mainly utilizes the <a href="http://arduino.cc/en/reference/homePage">Arduino API</a> for GPIO, SPI, and timing functions, which are easily replicated
+ * on various platforms. <br>Support files for these platforms are stored under RF24/utility, and can be modified to provide 
+ * the required functionality.
+ * 
+ * <br>
+ * @section Hardware_Templates Basic Hardware Template
+ *
+ * **RF24/utility**
+ *
+ * The RF24 library now includes a basic hardware template to assist in porting to various platforms. <br> The following files can be included
+ * to replicate standard Arduino functions as needed, allowing devices from ATTiny to Raspberry Pi to utilize the same core RF24 driver.
+ *
+ * | File               |                   Purpose                                                    | 
+ * |--------------------|------------------------------------------------------------------------------| 
+ * | RF24_arch_config.h | Basic Arduino/AVR compatibility, includes for remaining support files, etc   | 
+ * | includes.h         | Linux only. Defines specific platform, include correct RF24_arch_config file | 
+ * | spi.h              | Provides standardized SPI ( transfer() ) methods                         | 
+ * | gpio.h             | Provides standardized GPIO ( digitalWrite() ) methods                        | 
+ * | compatibility.h    | Provides standardized timing (millis(), delay()) methods                     | 
+ * | your_custom_file.h | Provides access to custom drivers for spi,gpio, etc                          | 
+ *
+ * <br>
+ * Examples are provided via the included hardware support templates in **RF24/utility** <br>
+ * See the <a href="modules.html">modules</a> page for examples of class declarations 
+ *
+ *<br>
+ * @section Device_Detection Device Detection
+ *
+ * 1. The main detection for Linux devices is done in the Makefile, with the includes.h from the proper hardware directory copied to RF24/utility/includes.h <br>
+ * 2. Secondary detection is completed in RF24_config.h, causing the include.h file to be included for all supported Linux devices <br>
+ * 3. RF24.h contains the declaration for SPI and GPIO objects 'spi' and 'gpio' to be used for porting-in related functions.
+ *
+ * <br>
+ * @section Ported_Code Code
+ * To have your ported code included in this library, or for assistance in porting, create a pull request or open an issue at https://github.com/TMRh20/RF24
+ * 
+ *
+ *<br><br><br>
+ */
+ 
+#endif // __RF24_H__
+
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/RF24_config.h	Sat Dec 03 08:21:37 2022 +0000
@@ -0,0 +1,68 @@
+/*
+ Copyright (C) 2011 J. Coliz <maniacbug@ymail.com>
+ This program is free software; you can redistribute it and/or
+ modify it under the terms of the GNU General Public License
+ version 2 as published by the Free Software Foundation.
+ */
+ 
+/*
+ * Mbed support added by Akash Vibhute <akash.roboticist@gmail.com>
+ * Porting completed on Nov/05/2015
+ *
+ * Updated 1: Synced with TMRh20's RF24 library on Nov/04/2015 from https://github.com/TMRh20
+ * Updated 2: Synced with TMRh20's RF24 library on Apr/18/2015 from https://github.com/TMRh20
+ *
+ */
+ 
+ 
+#ifndef __RF24_CONFIG_H__
+#define __RF24_CONFIG_H__
+ 
+/*** USER DEFINES:  ***/
+//#define FAILURE_HANDLING
+//#define SERIAL_DEBUG
+//#define MINIMAL
+/**********************/
+#define rf24_max(a,b) (a>b?a:b)
+#define rf24_min(a,b) (a<b?a:b)
+ 
+ 
+#include <mbed.h>
+ 
+// RF modules support 10 Mhz SPI bus speed
+const uint32_t RF_SPI_SPEED = 10000000;
+ 
+#define HIGH 1
+#define LOW 0
+ 
+//#include <stdint.h>
+//#include <stdio.h>
+//#include <string.h>
+ 
+#define _BV(x) (1<<(x))
+#define _SPI SPI
+ 
+#ifdef SERIAL_DEBUG
+#define IF_SERIAL_DEBUG(x) ({x;})
+#else
+#define IF_SERIAL_DEBUG(x)
+#endif
+ 
+//#define printf_P printf
+#define printf_P
+//#define _BV(bit) (1<<(bit))
+#define pgm_read_byte(addr) (*(const unsigned char *)(addr))
+ 
+typedef uint16_t prog_uint16_t;
+#define PSTR(x) (x)
+  #define sprintf(...) os_sprintf( __VA_ARGS__ )
+  //#define printf_P printf
+  #define printf_P
+  #define strlen_P strlen  
+  #define PROGMEM
+  #define pgm_read_byte(addr) (*(const unsigned char *)(addr))
+  #define pgm_read_word(p) (*(p))
+  #define PRIPSTR "%s"
+ 
+#endif // __RF24_CONFIG_H__
+
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp	Sat Dec 03 08:21:37 2022 +0000
@@ -0,0 +1,210 @@
+#include "mbed.h"
+#include "nRF24L01.h"
+#include "RF24.h"
+#include "RF24_config.h"
+
+Serial pc(PB_6, PB_7); //D5, D4 //PB_6, PB_7
+I2C i2c(PA_10, PA_9); //sda, scl PA_10, PA_9 D0, D1
+//(PinName mosi, PinName miso, PinName sck, PinName _cepin, PinName _csnpin)
+RF24 NRF24L01(PB_5, PB_4, PB_3, PA_12, PA_11);
+//RF24 NRF24L01(D11, D12, D13, D2, D10);
+
+AnalogIn JOYPIN1(PA_0); //A0
+AnalogIn JOYPIN2(PA_1); //A1
+AnalogIn JOYPIN3(PA_3); //A2
+AnalogIn JOYPIN4(PA_4); //A3
+
+AnalogIn POT1(PA_7); //A6
+AnalogIn POT2(PA_6); //A5
+AnalogIn POT3(PA_5); //A4
+
+DigitalIn BUTTON1(PA_2); //A7
+DigitalIn BUTTON2(PA_8); //D9
+
+DigitalOut MCU_LED(PB_0); //D3
+DigitalOut MCU_LED2(PB_1); //D6
+
+//MPU
+float mpu_temp_read;
+int32_t t_fine;
+int16_t gyro_raw[3], acc_raw[3], mag_raw[3];
+float gyro_offset[3], acc_offset[3];
+float mag_factory[3];
+int16_t angle[2];
+
+//magnetometer
+float x_offset = -1320.5, y_offset = 0, z_offset = -633.25;
+//float x_offset = -1320.5, y_offset = 1301.8, z_offset = -633.25;
+float x_scale = 0.9819, y_scale = 0.9957, z_scale = 1.0233;
+
+//RF
+const uint64_t pipe = 0x1212121212LL;
+float PITCH2 = 0, ROLL2 = 0, YAW2 = 0, THROTTLE2 = 0;
+int16_t PITCH = 0, ROLL = 0, YAW = 0, THROTTLE = 0;
+int8_t recv[30];
+int8_t trans[30];
+int8_t ackMessage[30];
+int16_t ackMessage2[30];
+uint32_t ackMessage3;
+int32_t ackMessage4[4];
+int8_t ackMessage5[3];
+
+//Timer Loop
+Timer timer1;
+
+int8_t TEMP_BUTTON1, TEMP_BUTTON2;
+int8_t temp_led = 1, temp_led2 = -1;
+int loop_count = 0, loop_count2 = 0, loop_count3 = 0, loop_count4 = 0, loop_count5 = 0; 
+int loop_count4_max = 50;
+float OFFSET1, OFFSET2, OFFSET3;
+
+int8_t current_mode = 0;
+
+int8_t toggle_mode = 1;
+
+//rf ack
+int8_t ack_count = 0;
+uint8_t cnt = 0;
+
+int32_t temp_time;
+uint8_t temp_time2;
+
+//-----------------------------------------------------------------------------------------
+
+int16_t constrain_int16(int16_t x, int16_t min, int16_t max)
+{
+    if (x > max) x = max;
+    else if (x < min) x = min;
+    
+    return x;
+}
+
+int32_t constrain_int32(int32_t x, int32_t min, int32_t max)
+{
+    if (x > max) x = max;
+    else if (x < min) x = min;
+    
+    return x;
+}
+
+float constrain_float(float x, float min, float max)
+{
+    if (x > max) x = max;
+    else if (x < min) x = min;
+    
+    return x;
+}
+
+//------------------------------------------------------------------------------------------------
+int main() {
+    
+    //disableDebugPorts();
+    //pc.baud(230400); //115200
+    //i2c.frequency(400000);
+
+    //RF
+    NRF24L01.begin();
+    NRF24L01.setDataRate(RF24_2MBPS); //RF24_2MBPS
+    NRF24L01.setChannel(22);
+    NRF24L01.setPayloadSize(28); //28
+    NRF24L01.setAddressWidth(5);
+    NRF24L01.setRetries(2,4); //1,3 2,8
+    
+    NRF24L01.enableAckPayload();
+    NRF24L01.openWritingPipe(pipe);
+    pc.printf("start\n\r");
+    int counta=0;
+    timer1.start();
+    
+//------------------------------------------------------------------------------------------------
+    while(1) {
+  
+    loop_count = loop_count + 1;
+    loop_count2 = loop_count2 + 1;
+    loop_count4 = loop_count4 + 1;
+
+    TEMP_BUTTON1 = (int8_t)BUTTON1;
+    TEMP_BUTTON2 = (int8_t)BUTTON2;
+
+        THROTTLE2 = JOYPIN1.read(); //left side vertical
+        PITCH2 = JOYPIN3.read() - 0.5f; //65536 //up positive
+        ROLL2 = JOYPIN4.read() - 0.5f; //right positive
+        YAW2 = JOYPIN2.read() - 0.5f; // right positive
+        
+        OFFSET1 = POT1.read() - 0.5f; //left //reduce value counter-clockwise
+        OFFSET2 = POT2.read() - 0.5f; //middle
+        OFFSET3 = POT3.read() - 0.5f; //right
+        //pc.printf("%f, %f, %f\n\r", OFFSET1, OFFSET2, OFFSET3);
+        
+        THROTTLE = (int16_t)(THROTTLE2 * 1024 * 1.15f);
+        THROTTLE = constrain_int16(THROTTLE, 0, 1500);
+        
+        PITCH = -(int16_t)((PITCH2 * 1024  / 2 - OFFSET2 * 1024 / 4)); //-
+        ROLL = -(int16_t)((ROLL2 * 1024 / 2 - OFFSET1 * 1024 / 4)); //-
+        YAW = (int16_t)((- YAW2 * 1024 / 6 + OFFSET3 * 1024 / 2));
+        
+    if (loop_count >= 4){
+        
+        trans[0] = ((char *)&ROLL)[0];
+        trans[1] = ((char *)&ROLL)[1];
+        trans[2] = ((char *)&PITCH)[0]; //0;//
+        trans[3] = ((char *)&PITCH)[1];
+        trans[4] = ((char *)&YAW)[0];
+        trans[5] = ((char *)&YAW)[1];
+        trans[6] = ((char *)&THROTTLE)[0];
+        trans[7] = ((char *)&THROTTLE)[1];
+        trans[8] = (char)BUTTON1;
+        trans[9] = (char)BUTTON2;
+        printf("transmit\t%d",counta);
+        counta++;
+        NRF24L01.powerUp();
+        NRF24L01.write(trans, 10);
+        
+/*       
+        if (NRF24L01.isAckPayloadAvailable()){
+            NRF24L01.read(ackMessage, 14); //28 23
+            
+            ackMessage2[0] = *(int16_t*)(&ackMessage[0]); 
+            ackMessage2[1] = *(int16_t*)(&ackMessage[2]); 
+            ackMessage2[2] = *(int16_t*)(&ackMessage[4]); 
+            
+            ackMessage2[3] = *(int16_t*)(&ackMessage[6]);
+            ackMessage2[4] = *(int16_t*)(&ackMessage[8]);
+            
+            ackMessage2[5] = *(int16_t*)(&ackMessage[10]);
+            ackMessage2[6] = *(int16_t*)(&ackMessage[12]);
+            
+            temp_time2 = (uint8_t)(temp_time / 100); //1000
+            
+            temp_time = 0;
+  
+        }    
+*/
+
+    loop_count = 0;
+    }
+
+    if (loop_count4 >= loop_count4_max){
+        
+        if (temp_led == 1) {
+            MCU_LED = 1;
+            //MCU_LED2 = 0;
+            }
+        if (temp_led == -1) {
+            MCU_LED = 0;
+            //MCU_LED2 = 1;
+            }
+        temp_led = -1 * temp_led;  
+        loop_count4 = 0;
+    }
+
+        while (timer1.read_us() < 2500); //400 Hz
+        
+        temp_time = temp_time + timer1.read_us();
+        
+        timer1.reset();
+        
+    }
+    
+}
+
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mbed.bld	Sat Dec 03 08:21:37 2022 +0000
@@ -0,0 +1,1 @@
+https://os.mbed.com/users/mbed_official/code/mbed/builds/a330f0fddbec
\ No newline at end of file
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mbed_config.h	Sat Dec 03 08:21:37 2022 +0000
@@ -0,0 +1,45 @@
+/*
+ * mbed SDK
+ * Copyright (c) 2017 ARM Limited
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+// Automatically generated configuration file.
+// DO NOT EDIT, content will be overwritten.
+
+#ifndef __MBED_CONFIG_DATA__
+#define __MBED_CONFIG_DATA__
+
+// Configuration parameters
+#define CLOCK_SOURCE                                USE_PLL_MSI                             // set by target:NUCLEO_L432KC
+#define LPTICKER_DELAY_TICKS                        0                                       // set by target:NUCLEO_L432KC
+#define MBED_CONF_PLATFORM_DEFAULT_SERIAL_BAUD_RATE 9600                                    // set by library:platform
+#define MBED_CONF_PLATFORM_STDIO_BAUD_RATE          9600                                    // set by library:platform
+#define MBED_CONF_PLATFORM_STDIO_CONVERT_NEWLINES   0                                       // set by library:platform
+#define MBED_CONF_PLATFORM_STDIO_FLUSH_AT_EXIT      1                                       // set by library:platform
+#define MBED_CONF_TARGET_BOOT_STACK_SIZE            0x400                                   // set by target:MCU_STM32_BAREMETAL
+#define MBED_CONF_TARGET_CONSOLE_UART               1                                       // set by target:Target
+#define MBED_CONF_TARGET_DEEP_SLEEP_LATENCY         4                                       // set by target:MCU_STM32
+#define MBED_CONF_TARGET_DEFAULT_ADC_VREF           NAN                                     // set by target:Target
+#define MBED_CONF_TARGET_INIT_US_TICKER_AT_BOOT     1                                       // set by target:MCU_STM32
+#define MBED_CONF_TARGET_LPTICKER_LPTIM             1                                       // set by target:NUCLEO_L432KC
+#define MBED_CONF_TARGET_LPTICKER_LPTIM_CLOCK       1                                       // set by target:MCU_STM32
+#define MBED_CONF_TARGET_LPUART_CLOCK_SOURCE        USE_LPUART_CLK_LSE|USE_LPUART_CLK_PCLK1 // set by target:MCU_STM32
+#define MBED_CONF_TARGET_LSE_AVAILABLE              1                                       // set by target:MCU_STM32
+#define MBED_CONF_TARGET_MPU_ROM_END                0x0fffffff                              // set by target:Target
+#define MBED_CONF_TARGET_TICKLESS_FROM_US_TICKER    0                                       // set by target:Target
+#define MBED_CONF_TARGET_XIP_ENABLE                 0                                       // set by target:Target
+
+#endif
+
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/nRF24L01.h	Sat Dec 03 08:21:37 2022 +0000
@@ -0,0 +1,137 @@
+/*
+    Copyright (c) 2007 Stefan Engelke <mbox@stefanengelke.de>
+    Portions Copyright (C) 2011 Greg Copeland
+ 
+    Permission is hereby granted, free of charge, to any person
+    obtaining a copy of this software and associated documentation
+    files (the "Software"), to deal in the Software without
+    restriction, including without limitation the rights to use, copy,
+    modify, merge, publish, distribute, sublicense, and/or sell copies
+    of the Software, and to permit persons to whom the Software is
+    furnished to do so, subject to the following conditions:
+ 
+    The above copyright notice and this permission notice shall be
+    included in all copies or substantial portions of the Software.
+ 
+    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+    EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+    MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+    NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
+    HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+    WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+    OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+    DEALINGS IN THE SOFTWARE.
+*/
+ 
+/*
+ * Mbed support added by Akash Vibhute <akash.roboticist@gmail.com>
+ * Porting completed on Nov/05/2015
+ *
+ * Updated 1: Synced with TMRh20's RF24 library on Nov/04/2015 from https://github.com/TMRh20
+ * Updated 2: Synced with TMRh20's RF24 library on Apr/18/2015 from https://github.com/TMRh20
+ *
+ */
+ 
+/* Memory Map */
+#define NRF_CONFIG      0x00
+#define EN_AA       0x01
+#define EN_RXADDR   0x02
+#define SETUP_AW    0x03
+#define SETUP_RETR  0x04
+#define RF_CH       0x05
+#define RF_SETUP    0x06
+#define NRF_STATUS  0x07
+#define OBSERVE_TX  0x08
+#define CD          0x09
+#define RX_ADDR_P0  0x0A
+#define RX_ADDR_P1  0x0B
+#define RX_ADDR_P2  0x0C
+#define RX_ADDR_P3  0x0D
+#define RX_ADDR_P4  0x0E
+#define RX_ADDR_P5  0x0F
+#define TX_ADDR     0x10
+#define RX_PW_P0    0x11
+#define RX_PW_P1    0x12
+#define RX_PW_P2    0x13
+#define RX_PW_P3    0x14
+#define RX_PW_P4    0x15
+#define RX_PW_P5    0x16
+#define FIFO_STATUS 0x17
+#define DYNPD       0x1C
+#define FEATURE     0x1D
+ 
+/* Bit Mnemonics */
+#define MASK_RX_DR  6
+#define MASK_TX_DS  5
+#define MASK_MAX_RT 4
+#define EN_CRC      3
+#define CRCO        2
+#define PWR_UP      1
+#define PRIM_RX     0
+#define ENAA_P5     5
+#define ENAA_P4     4
+#define ENAA_P3     3
+#define ENAA_P2     2
+#define ENAA_P1     1
+#define ENAA_P0     0
+#define ERX_P5      5
+#define ERX_P4      4
+#define ERX_P3      3
+#define ERX_P2      2
+#define ERX_P1      1
+#define ERX_P0      0
+#define AW          0
+#define ARD         4
+#define ARC         0
+#define PLL_LOCK    4
+#define RF_DR       3
+#define RF_PWR      6
+#define RX_DR       6
+#define TX_DS       5
+#define MAX_RT      4
+#define RX_P_NO     1
+#define TX_FULL     0
+#define PLOS_CNT    4
+#define ARC_CNT     0
+#define TX_REUSE    6
+#define FIFO_FULL   5
+#define TX_EMPTY    4
+#define RX_FULL     1
+#define RX_EMPTY    0
+#define DPL_P5      5
+#define DPL_P4      4
+#define DPL_P3      3
+#define DPL_P2      2
+#define DPL_P1      1
+#define DPL_P0      0
+#define EN_DPL      2
+#define EN_ACK_PAY  1
+#define EN_DYN_ACK  0
+ 
+/* Instruction Mnemonics */
+#define R_REGISTER    0x00
+#define W_REGISTER    0x20
+#define REGISTER_MASK 0x1F
+#define ACTIVATE      0x50
+#define R_RX_PL_WID   0x60
+#define R_RX_PAYLOAD  0x61
+#define W_TX_PAYLOAD  0xA0
+#define W_ACK_PAYLOAD 0xA8
+#define FLUSH_TX      0xE1
+#define FLUSH_RX      0xE2
+#define REUSE_TX_PL   0xE3
+#define NOP           0xFF
+ 
+/* Non-P omissions */
+#define LNA_HCURR   0
+ 
+/* P model memory Map */
+#define RPD         0x09
+#define W_TX_PAYLOAD_NO_ACK  0xB0
+ 
+/* P model bit Mnemonics */
+#define RF_DR_LOW   5
+#define RF_DR_HIGH  3
+#define RF_PWR_LOW  1
+#define RF_PWR_HIGH 2
+