Diff: RF24.cpp

Revision:

0:bb74812ac6bb

Child:

1:00706a42491e

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/RF24.cpp	Mon Jul 06 05:10:50 2015 +0000
@@ -0,0 +1,1003 @@
+/*
+ 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.
+ */
+
+#include "RF24.h"
+
+/****************************************************************************/
+
+void RF24::csn(int mode)
+{
+  // Minimum ideal spi bus speed is 2x data rate
+  // If we assume 2Mbs data rate and 16Mhz clock, a
+  // divider of 4 is the minimum we want.
+  // CLK:BUS 8Mhz:2Mhz, 16Mhz:4Mhz, or 20Mhz:5Mhz
+//#ifdef ARDUINO
+//  spi.setBitOrder(MSBFIRST);
+//  spi.setDataMode(spi_MODE0);
+//  spi.setClockDivider(spi_CLOCK_DIV4);
+//#endif
+//  digitalWrite(csn_pin,mode);
+    csn_pin = mode;
+    
+}
+
+/****************************************************************************/
+
+void RF24::ce(int level)
+{
+  //digitalWrite(ce_pin,level);
+  ce_pin = level;
+}
+
+/****************************************************************************/
+
+uint8_t RF24::read_register(uint8_t reg, uint8_t* buf, uint8_t len)
+{
+  uint8_t status;
+
+  csn(LOW);
+  status = spi.write( R_REGISTER | ( REGISTER_MASK & reg ) );
+  while ( len-- )
+    *buf++ = spi.write(0xff);
+
+  csn(HIGH);
+
+  return status;
+}
+
+/****************************************************************************/
+
+uint8_t RF24::read_register(uint8_t reg)
+{
+  csn(LOW);
+  spi.write( R_REGISTER | ( REGISTER_MASK & reg ) );
+  uint8_t result = spi.write(0xff);
+
+  csn(HIGH);
+  return result;
+}
+
+/****************************************************************************/
+
+uint8_t RF24::write_register(uint8_t reg, const uint8_t* buf, uint8_t len)
+{
+  uint8_t status;
+
+  csn(LOW);
+  status = spi.write( W_REGISTER | ( REGISTER_MASK & reg ) );
+  while ( len-- )
+    spi.write(*buf++);
+
+  csn(HIGH);
+
+  return status;
+}
+
+/****************************************************************************/
+
+uint8_t RF24::write_register(uint8_t reg, uint8_t value)
+{
+  uint8_t status;
+
+//  IF_SERIAL_DEBUG(printf(("write_register(%02x,%02x)\r\n"),reg,value));
+
+  csn(LOW);
+  status = spi.write( W_REGISTER | ( REGISTER_MASK & reg ) );
+  spi.write(value);
+  csn(HIGH);
+
+  return status;
+}
+
+/****************************************************************************/
+
+uint8_t RF24::write_payload(const void* buf, uint8_t len)
+{
+  uint8_t status;
+
+  const uint8_t* current = reinterpret_cast<const uint8_t*>(buf);
+
+  uint8_t data_len = min(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);
+  
+  csn(LOW);
+  status = spi.write( W_TX_PAYLOAD );
+  while ( data_len-- )
+    spi.write(*current++);
+  while ( blank_len-- )
+    spi.write(0);
+  csn(HIGH);
+
+  return status;
+}
+
+/****************************************************************************/
+
+uint8_t RF24::read_payload(void* buf, uint8_t len)
+{
+  uint8_t status;
+  uint8_t* current = reinterpret_cast<uint8_t*>(buf);
+
+  uint8_t data_len = min(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);
+  
+  csn(LOW);
+  status = spi.write( R_RX_PAYLOAD );
+  while ( data_len-- )
+    *current++ = spi.write(0xff);
+  while ( blank_len-- )
+    spi.write(0xff);
+  csn(HIGH);
+
+  return status;
+}
+
+/****************************************************************************/
+
+uint8_t RF24::flush_rx(void)
+{
+  uint8_t status;
+
+  csn(LOW);
+  status = spi.write( FLUSH_RX );
+  csn(HIGH);
+
+  return status;
+}
+
+/****************************************************************************/
+
+uint8_t RF24::flush_tx(void)
+{
+  uint8_t status;
+
+  csn(LOW);
+  status = spi.write( FLUSH_TX );
+  csn(HIGH);
+
+  return status;
+}
+
+/****************************************************************************/
+
+uint8_t RF24::get_status(void)
+{
+  uint8_t status;
+
+  csn(LOW);
+  status = spi.write( NOP );
+  csn(HIGH);
+
+  return status;
+}
+
+/****************************************************************************/
+
+void RF24::print_status(uint8_t status)
+{
+  printf(("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) & 7),
+           (status & _BV(TX_FULL))?1:0
+          );
+}
+
+/****************************************************************************/
+
+void RF24::print_observe_tx(uint8_t value)
+{
+  printf(("OBSERVE_TX=%02x: POLS_CNT=%x ARC_CNT=%x\r\n"),
+           value,
+           (value >> PLOS_CNT) & 15,
+           (value >> ARC_CNT) & 15
+          );
+}
+
+/****************************************************************************/
+
+void RF24::print_byte_register(const char* name, uint8_t reg, uint8_t qty)
+{
+//  char extra_tab = strlen(name) < 8 ? '\t' : 0;
+  printf("%s =",name);
+  while (qty--)
+    printf((" 0x%02x"),read_register(reg++));
+  printf(("\r\n"));
+}
+
+/****************************************************************************/
+
+void RF24::print_address_register(const char* name, uint8_t reg, uint8_t qty)
+{
+//  char extra_tab = strlen_P(name) < 8 ? '\t' : 0;
+  printf("%s =",name);
+
+  while (qty--)
+  {
+    uint8_t buffer[5];
+    read_register(reg++,buffer,sizeof buffer);
+
+    printf((" 0x"));
+    uint8_t* bufptr = buffer + sizeof buffer;
+    while( --bufptr >= buffer )
+      printf(("%02x"),*bufptr);
+  }
+
+  printf(("\r\n"));
+}
+
+/****************************************************************************/
+
+RF24::RF24(PinName mosi, PinName miso, PinName sck, PinName _csnpin, PinName _cepin):
+  ce_pin(_cepin), csn_pin(_csnpin), wide_band(true), p_variant(false), 
+  payload_size(32), ack_payload_available(false), dynamic_payloads_enabled(false),
+  pipe0_reading_address(0), spi(mosi, miso, sck)
+{
+    spi.frequency(10000000/5);     // 2Mbit, 1/5th the maximum transfer rate for the spi bus
+    spi.format(8,0);                                   // 8-bit, ClockPhase = 0, ClockPolarity = 0
+    wait_ms(100);
+}
+
+/****************************************************************************/
+
+void RF24::setChannel(uint8_t channel)
+{
+  // TODO: This method could take advantage of the 'wide_band' calculation
+  // done in setChannel() to require certain channel spacing.
+
+  const uint8_t max_channel = 127;
+  write_register(RF_CH,min(channel,max_channel));
+}
+
+/****************************************************************************/
+
+void RF24::setPayloadSize(uint8_t size)
+{
+  const uint8_t max_payload_size = 32;
+  payload_size = min(size,max_payload_size);
+}
+
+/****************************************************************************/
+
+uint8_t RF24::getPayloadSize(void)
+{
+  return payload_size;
+}
+
+/****************************************************************************/
+
+static const char rf24_datarate_e_str_0[]  = "1MBPS";
+static const char rf24_datarate_e_str_1[]  = "2MBPS";
+static const char rf24_datarate_e_str_2[]  = "250KBPS";
+static const char * const rf24_datarate_e_str_P[]  = {
+  rf24_datarate_e_str_0,
+  rf24_datarate_e_str_1,
+  rf24_datarate_e_str_2,
+};
+static const char rf24_model_e_str_0[]  = "nRF24L01";
+static const char rf24_model_e_str_1[]  = "nRF24L01+";
+static const char * const rf24_model_e_str_P[]  = {
+  rf24_model_e_str_0,
+  rf24_model_e_str_1,
+};
+static const char rf24_crclength_e_str_0[]  = "Disabled";
+static const char rf24_crclength_e_str_1[]  = "8 bits";
+static const char rf24_crclength_e_str_2[]  = "16 bits" ;
+static const char * const rf24_crclength_e_str_P[]  = {
+  rf24_crclength_e_str_0,
+  rf24_crclength_e_str_1,
+  rf24_crclength_e_str_2,
+};
+static const char rf24_pa_dbm_e_str_0[]  = "PA_MIN";
+static const char rf24_pa_dbm_e_str_1[]  = "PA_LOW";
+static const char rf24_pa_dbm_e_str_2[]  = "PA_MED";
+static const char rf24_pa_dbm_e_str_3[]  = "PA_HIGH";
+static const char * const rf24_pa_dbm_e_str_P[]  = { 
+  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(("RX_ADDR_P0-1"),RX_ADDR_P0,2);
+  print_byte_register(("RX_ADDR_P2-5"),RX_ADDR_P2,4);
+  print_address_register(("TX_ADDR"),TX_ADDR);
+
+  print_byte_register(("RX_PW_P0-6"),RX_PW_P0,6);
+  print_byte_register(("EN_AA"),EN_AA);
+  print_byte_register(("EN_RXADDR"),EN_RXADDR);
+  print_byte_register(("RF_CH"),RF_CH);
+  print_byte_register(("RF_SETUP"),RF_SETUP);
+  print_byte_register(("CONFIG"),CONFIG);
+  print_byte_register(("DYNPD/FEATURE"),DYNPD,2);
+
+  printf(("Data Rate\t = %s\r\n"), rf24_datarate_e_str_P[getDataRate()]);
+  printf(("Model\t\t = %s\r\n"), rf24_model_e_str_P[isPVariant()]);
+  printf(("CRC Length\t = %s\r\n"),rf24_crclength_e_str_P[getCRCLength()]);
+  printf(("PA Power\t = %s\r\n"),rf24_pa_dbm_e_str_P[getPALevel()]);
+}
+
+/****************************************************************************/
+
+void RF24::begin(void)
+{
+  // Initialize pins
+//  pinMode(ce_pin,OUTPUT);
+//  pinMode(csn_pin,OUTPUT);
+
+  // Initialize spi bus
+  //spi.begin();
+  mainTimer.start();
+
+  ce(LOW);
+  csn(HIGH);
+
+  // 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: wait_ms is based on P-variant whereby non-P *may* require different timing.
+  wait_ms( 5 ) ;
+
+  // 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.
+  write_register(SETUP_RETR,(4 << ARD) | (15 << ARC));
+
+  // Restore our default PA level
+  setPALevel( RF24_PA_MAX ) ;
+
+  // Determine if this is a p or non-p RF24 module and then
+  // reset our data rate back to default value. This works
+  // because a non-P variant won't allow the data rate to
+  // be set to 250Kbps.
+  if( setDataRate( RF24_250KBPS ) )
+  {
+    p_variant = true ;
+  }
+  
+  // Then set the data rate to the slowest (and most reliable) speed supported by all
+  // hardware.
+  setDataRate( RF24_1MBPS ) ;
+
+  // Initialize CRC and request 2-byte (16bit) CRC
+  setCRCLength( RF24_CRC_16 ) ;
+  
+  // Disable dynamic payloads, to match dynamic_payloads_enabled setting
+  write_register(DYNPD,0);
+
+  // Reset current status
+  // Notice reset and flush is the last thing we do
+  write_register(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);
+  setChannel(90);
+
+  // Flush buffers
+  flush_rx();
+  flush_tx();
+  
+  // set EN_RXADDRR to 0 to fix pipe 0 from receiving
+  write_register(EN_RXADDR, 0);
+}
+
+/****************************************************************************/
+
+void RF24::startListening(void)
+{
+  write_register(CONFIG, read_register(CONFIG) | _BV(PWR_UP) | _BV(PRIM_RX));
+  write_register(STATUS, _BV(RX_DR) | _BV(TX_DS) | _BV(MAX_RT) );
+
+  // Restore the pipe0 adddress, if exists
+  if (pipe0_reading_address)
+    write_register(RX_ADDR_P0, reinterpret_cast<const uint8_t*>(&pipe0_reading_address), 5);
+
+  // Flush buffers
+  flush_rx();
+  flush_tx();
+
+  // Go!
+  ce(HIGH);
+
+  // wait for the radio to come up (130us actually only needed)
+//  wait_msMicroseconds(130);
+    wait_us(130);
+}
+
+/****************************************************************************/
+
+void RF24::stopListening(void)
+{
+  ce(LOW);
+  flush_tx();
+  flush_rx();
+}
+
+/****************************************************************************/
+
+void RF24::powerDown(void)
+{
+  write_register(CONFIG,read_register(CONFIG) & ~_BV(PWR_UP));
+}
+
+/****************************************************************************/
+
+void RF24::powerUp(void)
+{
+  write_register(CONFIG,read_register(CONFIG) | _BV(PWR_UP));
+}
+
+/******************************************************************/
+
+bool RF24::write( const void* buf, uint8_t len )
+{
+  bool result = false;
+
+  // Begin the write
+  startWrite(buf,len);
+
+  // ------------
+  // At this point we could return from a non-blocking write, and then call
+  // the rest after an interrupt
+
+  // Instead, we are going to block here until we get TX_DS (transmission completed and ack'd)
+  // or MAX_RT (maximum retries, transmission failed).  Also, we'll timeout in case the radio
+  // is flaky and we get neither.
+
+  // IN the end, the send should be blocking.  It comes back in 60ms worst case, or much faster
+  // if I tighted up the retry logic.  (Default settings will be 1500us.
+  // Monitor the send
+  uint8_t observe_tx;
+  uint8_t status;
+  uint32_t sent_at = mainTimer.read_ms();
+  const uint32_t timeout = 500; //ms to wait for timeout
+  do
+  {
+    status = read_register(OBSERVE_TX,&observe_tx,1);
+//    IF_SERIAL_DEBUG(Serial.print(observe_tx,HEX));
+  }
+  while( ! ( status & ( _BV(TX_DS) | _BV(MAX_RT) ) ) && ( mainTimer.read_ms() - sent_at < timeout ) );
+
+  // The part above is what you could recreate with your own interrupt handler,
+  // and then call this when you got an interrupt
+  // ------------
+
+  // Call this when you get an interrupt
+  // The status tells us three things
+  // * The send was successful (TX_DS)
+  // * The send failed, too many retries (MAX_RT)
+  // * There is an ack packet waiting (RX_DR)
+  bool tx_ok, tx_fail;
+  whatHappened(tx_ok,tx_fail,ack_payload_available);
+  
+  //printf("%u%u%u\r\n",tx_ok,tx_fail,ack_payload_available);
+
+  result = tx_ok;
+//  IF_SERIAL_DEBUG(Serial.print(result?"...OK.":"...Failed"));
+
+  // Handle the ack packet
+  if ( ack_payload_available )
+  {
+    ack_payload_length = getDynamicPayloadSize();
+//    IF_SERIAL_DEBUG(Serial.print("[AckPacket]/"));
+//    IF_SERIAL_DEBUG(Serial.println(ack_payload_length,DEC));
+  }
+
+  // Yay, we are done.
+
+  // Power down
+//  powerDown();
+
+  // Flush buffers (Is this a relic of past experimentation, and not needed anymore?
+//  flush_tx();
+
+  return result;
+}
+/****************************************************************************/
+
+void RF24::startWrite( const void* buf, uint8_t len )
+{
+  // Transmitter power-up
+  write_register(CONFIG, ( read_register(CONFIG) | _BV(PWR_UP) ) & ~_BV(PRIM_RX) );
+//  wait_msMicroseconds(150);
+    wait_us(130);
+
+  // Send the payload
+  write_payload( buf, len );
+
+  // Allons!
+  ce(HIGH);
+//  wait_msMicroseconds(15);
+    wait_us(15); 
+  ce(LOW);
+}
+
+/****************************************************************************/
+
+uint8_t RF24::getDynamicPayloadSize(void)
+{
+  uint8_t result = 0;
+
+  csn(LOW);
+  spi.write( R_RX_PL_WID );
+  result = spi.write(0xff);
+  csn(HIGH);
+
+  return result;
+}
+
+/****************************************************************************/
+
+bool RF24::available(void)
+{
+  return available(NULL);
+}
+
+/****************************************************************************/
+
+bool RF24::available(uint8_t* pipe_num)
+{
+  uint8_t status = get_status();
+
+  // Too noisy, enable if you really want lots o data!!
+  //IF_SERIAL_DEBUG(print_status(status));
+
+  bool result = ( status & _BV(RX_DR) );
+
+  if (result)
+  {
+    // If the caller wants the pipe number, include that
+    if ( pipe_num )
+      *pipe_num = ( status >> RX_P_NO ) & 7;
+
+    // Clear the status bit
+
+    // ??? Should this REALLY be cleared now?  Or wait until we
+    // actually READ the payload?
+
+    write_register(STATUS,_BV(RX_DR) );
+
+    // Handle ack payload receipt
+    if ( status & _BV(TX_DS) )
+    {
+      write_register(STATUS,_BV(TX_DS));
+    }
+  }
+
+  return result;
+}
+
+/****************************************************************************/
+
+bool RF24::read( void* buf, uint8_t len )
+{
+  // Fetch the payload
+  read_payload( buf, len );
+
+  // was this the last of the data available?
+  return read_register(FIFO_STATUS) & _BV(RX_EMPTY);
+}
+
+/****************************************************************************/
+
+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(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), 5);
+  write_register(TX_ADDR, reinterpret_cast<uint8_t*>(&value), 5);
+
+  const uint8_t max_payload_size = 32;
+  write_register(RX_PW_P0,min(payload_size,max_payload_size));
+  
+  flush_tx();
+}
+
+/****************************************************************************/
+
+static const uint8_t child_pipe[]  =
+{
+  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[]  =
+{
+  RX_PW_P0, RX_PW_P1, RX_PW_P2, RX_PW_P3, RX_PW_P4, RX_PW_P5
+};
+static const uint8_t child_pipe_enable[]  =
+{
+  ERX_P0, ERX_P1, ERX_P2, ERX_P3, ERX_P4, ERX_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)
+    pipe0_reading_address = address;
+
+  if (child <= 6)
+  {
+    // For pipes 2-5, only write the LSB
+    if ( child < 2 )
+      write_register(child_pipe[child], reinterpret_cast<const uint8_t*>(&address), 5);
+    else
+      write_register(child_pipe[child], reinterpret_cast<const uint8_t*>(&address), 1);
+
+    write_register(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(child_pipe_enable[child]));
+  }
+}
+
+/****************************************************************************/
+
+void RF24::toggle_features(void)
+{
+  csn(LOW);
+  spi.write( ACTIVATE );
+  spi.write( 0x73 );
+  csn(HIGH);
+}
+
+/****************************************************************************/
+
+void RF24::enableDynamicPayloads(void)
+{
+  // Enable dynamic payload throughout the system
+  write_register(FEATURE,read_register(FEATURE) | _BV(EN_DPL) );
+
+  // If it didn't work, the features are not enabled
+  if ( ! read_register(FEATURE) )
+  {
+    // So enable them and try again
+    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
+  //
+
+  write_register(FEATURE,read_register(FEATURE) | _BV(EN_ACK_PAY) | _BV(EN_DPL) );
+
+  // If it didn't work, the features are not enabled
+  if ( ! read_register(FEATURE) )
+  {
+    // So enable them and try again
+    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));
+}
+
+/****************************************************************************/
+
+void RF24::writeAckPayload(uint8_t pipe, const void* buf, uint8_t len)
+{
+  const uint8_t* current = reinterpret_cast<const uint8_t*>(buf);
+
+  csn(LOW);
+  spi.write( W_ACK_PAYLOAD | ( pipe & 7 ) );
+  const uint8_t max_payload_size = 32;
+  uint8_t data_len = min(len,max_payload_size);
+  while ( data_len-- )
+    spi.write(*current++);
+
+  csn(HIGH);
+}
+
+/****************************************************************************/
+
+bool RF24::isAckPayloadAvailable(void)
+{
+  bool result = ack_payload_available;
+  ack_payload_available = false;
+  return result;
+}
+
+/****************************************************************************/
+
+bool RF24::isPVariant(void)
+{
+  return p_variant ;
+}
+
+/****************************************************************************/
+
+void RF24::setAutoAck(bool enable)
+{
+  if ( enable )
+    write_register(EN_AA, 63);
+  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(rf24_pa_dbm_e level)
+{
+  uint8_t setup = read_register(RF_SETUP) ;
+  setup &= ~(_BV(RF_PWR_LOW) | _BV(RF_PWR_HIGH)) ;
+
+  // switch uses RAM (evil!)
+  if ( level == RF24_PA_MAX )
+  {
+    setup |= (_BV(RF_PWR_LOW) | _BV(RF_PWR_HIGH)) ;
+  }
+  else if ( level == RF24_PA_HIGH )
+  {
+    setup |= _BV(RF_PWR_HIGH) ;
+  }
+  else if ( level == RF24_PA_LOW )
+  {
+    setup |= _BV(RF_PWR_LOW);
+  }
+  else if ( level == RF24_PA_MIN )
+  {
+    // nothing
+  }
+  else if ( level == RF24_PA_ERROR )
+  {
+    // On error, go to maximum PA
+    setup |= (_BV(RF_PWR_LOW) | _BV(RF_PWR_HIGH)) ;
+  }
+
+  write_register( RF_SETUP, setup ) ;
+}
+
+/****************************************************************************/
+
+rf24_pa_dbm_e RF24::getPALevel(void)
+{
+  rf24_pa_dbm_e result = RF24_PA_ERROR ;
+  uint8_t power = read_register(RF_SETUP) & (_BV(RF_PWR_LOW) | _BV(RF_PWR_HIGH)) ;
+
+  // switch uses RAM (evil!)
+  if ( power == (_BV(RF_PWR_LOW) | _BV(RF_PWR_HIGH)) )
+  {
+    result = RF24_PA_MAX ;
+  }
+  else if ( power == _BV(RF_PWR_HIGH) )
+  {
+    result = RF24_PA_HIGH ;
+  }
+  else if ( power == _BV(RF_PWR_LOW) )
+  {
+    result = RF24_PA_LOW ;
+  }
+  else
+  {
+    result = RF24_PA_MIN ;
+  }
+
+  return result ;
+}
+
+/****************************************************************************/
+
+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
+  wide_band = false ;
+  setup &= ~(_BV(RF_DR_LOW) | _BV(RF_DR_HIGH)) ;
+  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'.
+    wide_band = false ;
+    setup |= _BV( RF_DR_LOW ) ;
+  }
+  else
+  {
+    // Set 2Mbs, RF_DR (RF_DR_HIGH) is set 1
+    // Making it '01'
+    if ( speed == RF24_2MBPS )
+    {
+      wide_band = true ;
+      setup |= _BV(RF_DR_HIGH);
+    }
+    else
+    {
+      // 1Mbs
+      wide_band = false ;
+    }
+  }
+  write_register(RF_SETUP,setup);
+
+  // Verify our result
+  if ( read_register(RF_SETUP) == setup )
+  {
+    result = true;
+  }
+  else
+  {
+    wide_band = false;
+  }
+
+  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(CONFIG) & ~( _BV(CRCO) | _BV(EN_CRC)) ;
+ 
+  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( CONFIG, config ) ;
+}
+
+/****************************************************************************/
+
+rf24_crclength_e RF24::getCRCLength(void)
+{
+  rf24_crclength_e result = RF24_CRC_DISABLED;
+  uint8_t config = read_register(CONFIG) & ( _BV(CRCO) | _BV(EN_CRC)) ;
+
+  if ( config & _BV(EN_CRC ) )
+  {
+    if ( config & _BV(CRCO) )
+      result = RF24_CRC_16;
+    else
+      result = RF24_CRC_8;
+  }
+
+  return result;
+}
+
+/****************************************************************************/
+
+void RF24::disableCRC( void )
+{
+  uint8_t disable = read_register(CONFIG) & ~_BV(EN_CRC) ;
+  write_register( CONFIG, disable ) ;
+}
+
+/****************************************************************************/
+void RF24::setRetries(uint8_t delay, uint8_t count)
+{
+ write_register(SETUP_RETR,(delay&0xf)<<ARD | (count&0xf)<<ARC);
+}
+
+uint8_t RF24::min(uint8_t a, uint8_t b)
+{
+    if(a < b)
+        return a;
+    else
+        return b;
+}