Revision 2:75a5b58b2338, committed 2019-03-25

Comitter:

iforce2d

Date:

Mon Mar 25 07:35:02 2019 +0000

Parent:

1:5be2682710c6

Commit message:

Basic port of gcopeland nRF24L01 library

Changed in this revision

diff -r 5be2682710c6 -r 75a5b58b2338 Clock.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Clock.cpp	Mon Mar 25 07:35:02 2019 +0000
@@ -0,0 +1,65 @@
+#include <mbed.h>
+ 
+// The us ticker is a wrapping uint32_t. We insert interrupts at
+// 0, 0x40000000, 0x8000000, and 0xC0000000, rather than just 0 or just 0xFFFFFFFF because there is
+// code that calls interrupts that are "very soon" immediately and we don't
+// want that. Also because if we only use 0 and 0x80000000 then there is a chance it would
+// be considered to be in the past and executed immediately.
+ 
+class ExtendedClock : public TimerEvent
+{
+public:
+    ExtendedClock()
+    {
+        // This also starts the us ticker.
+        mTriggers = 0;
+        insert(0x40000000);
+    }
+ 
+    float read()
+    {
+        return read_us() / 1000000.0f;
+    }
+ 
+    uint64_t read_ms()
+    {
+        return read_us() / 1000;
+    }
+ 
+    uint64_t read_us()
+    {
+        return mTriggers * 0x40000000ull + (ticker_read(_ticker_data) & 0x3FFFFFFF);
+    }
+ 
+private:
+    void handler() 
+    {
+        ++mTriggers;
+        // If this is the first time we've been called (at 0x4...)
+        // then mTriggers now equals 1 and we want to insert at 0x80000000.
+        insert((mTriggers+1) * 0x40000000);
+    }
+ 
+    // The number of times the us_ticker has rolled over.
+    uint32_t mTriggers;
+};
+ 
+static ExtendedClock _GlobalClock;
+ 
+// Return the number of seconds since boot.
+float clock_s()
+{
+    return _GlobalClock.read();
+}
+ 
+// Return the number of milliseconds since boot.
+uint64_t clock_ms()
+{
+    return _GlobalClock.read_ms();
+}
+ 
+// Return the number of microseconds since boot.
+uint64_t clock_us()
+{
+    return _GlobalClock.read_us();
+}
\ No newline at end of file

diff -r 5be2682710c6 -r 75a5b58b2338 Clock.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Clock.h	Mon Mar 25 07:35:02 2019 +0000
@@ -0,0 +1,12 @@
+#pragma once
+ 
+#include <stdint.h>
+ 
+// Return the number of seconds since boot.
+float clock_s();
+ 
+// Return the number of milliseconds since boot.
+uint64_t clock_ms();
+ 
+// Return the number of microseconds since boot.
+uint64_t clock_us();
\ No newline at end of file

diff -r 5be2682710c6 -r 75a5b58b2338 RF24.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/RF24.cpp	Mon Mar 25 07:35:02 2019 +0000
@@ -0,0 +1,973 @@
+/*
+ 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 "nRF24L01.h"
+#include "RF24_config.h"
+#include "RF24.h"
+#include "Clock.h"
+
+#define LOW 0
+#define HIGH 1
+
+#ifndef min 
+#define min(a,b) (((a) < (b))? (a) : (b))
+#endif
+
+/****************************************************************************/
+
+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
+  do_csn = mode;
+}
+
+/****************************************************************************/
+
+void RF24::ce(int level)
+{
+  do_ce = 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;
+
+  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;
+    
+  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;
+    
+  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(Serial& serial, uint8_t status)
+{
+  serial.printf("STATUS\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) & 0x07),
+           (status & _BV(TX_FULL))?1:0
+          );
+}
+
+/****************************************************************************/
+
+void RF24::print_observe_tx(Serial& serial, uint8_t value)
+{
+  serial.printf("OBSERVE_TX=%02x: POLS_CNT=%x ARC_CNT=%x\r\n",
+           value,
+           (value >> PLOS_CNT) & 0x0F,
+           (value >> ARC_CNT) & 0x0F
+          );
+}
+
+/****************************************************************************/
+
+void RF24::print_byte_register(Serial& serial, const char* name, uint8_t reg, uint8_t qty)
+{
+  serial.printf("\t%s =",name);
+  while (qty--)
+    serial.printf(" 0x%02x",read_register(reg++));
+  serial.printf("\r\n");
+}
+
+/****************************************************************************/
+
+void RF24::print_address_register(Serial& serial, const char* name, uint8_t reg, uint8_t qty)
+{
+  serial.printf("\t%s =",name);
+
+  while (qty--)
+  {
+    uint8_t buffer[5];
+    read_register(reg++,buffer,sizeof buffer);
+
+    serial.printf(" 0x");
+    uint8_t* bufptr = buffer + sizeof buffer;
+    while( --bufptr >= buffer )
+      serial.printf("%02x",*bufptr);
+  }
+
+  serial.printf("\r\n");
+}
+
+/****************************************************************************/
+
+RF24::RF24(PinName mosi, 
+                     PinName miso, 
+                     PinName sck, 
+                     PinName csn,
+                     PinName ce) : spi(mosi, miso, sck), do_csn(csn), do_ce(ce), wide_band(true), p_variant(false), 
+  payload_size(32), ack_payload_available(false), dynamic_payloads_enabled(false),
+  pipe0_reading_address(0)
+{
+}
+
+/****************************************************************************/
+
+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[] = "LA_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(Serial& serial)
+{
+  print_status(serial, get_status());
+
+  print_address_register(serial, "RX_ADDR_P0-1",RX_ADDR_P0,2);
+  print_byte_register(serial, "RX_ADDR_P2-5",RX_ADDR_P2,4);
+  print_address_register(serial, "TX_ADDR",TX_ADDR);
+
+  print_byte_register(serial, "RX_PW_P0-6",RX_PW_P0,6);
+  print_byte_register(serial, "EN_AA",EN_AA);
+  print_byte_register(serial, "EN_RXADDR",EN_RXADDR);
+  print_byte_register(serial, "RF_CH",RF_CH);
+  print_byte_register(serial, "RF_SETUP",RF_SETUP);
+  print_byte_register(serial, "CONFIG",CONFIG);
+  print_byte_register(serial, "DYNPD/FEATURE",DYNPD,2);
+
+  serial.printf("Data Rate\t = %S\r\n",rf24_datarate_e_str_P[getDataRate()]);
+  serial.printf("Model\t\t = %S\r\n",rf24_model_e_str_P[isPVariant()]);
+  serial.printf("CRC Length\t = %S\r\n",rf24_crclength_e_str_P[getCRCLength()]);
+  serial.printf("PA Power\t = %S\r\n",rf24_pa_dbm_e_str_P[getPALevel()]);
+}
+
+/****************************************************************************/
+
+void RF24::begin(void)
+{
+  timer.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: Delay 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,(0x04 << ARD) | (0x0F << 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);
+
+  // Flush buffers
+  flush_rx();
+  flush_tx();
+}
+
+/****************************************************************************/
+
+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_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 = clock_ms();
+  const uint32_t timeout = 500; //ms to wait for timeout
+  do
+  {
+    status = read_register(OBSERVE_TX,&observe_tx,1);
+  }
+  while( ! ( status & ( _BV(TX_DS) | _BV(MAX_RT) ) ) && ( clock_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;
+
+  // Handle the ack packet
+  if ( ack_payload_available )
+  {
+    ack_payload_length = getDynamicPayloadSize();
+  }
+
+  // Yay, we are done.
+
+  // Power down
+  powerDown();
+
+  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_us(150);
+
+  // Send the payload
+  write_payload( buf, len );
+
+  // Allons!
+  ce(HIGH);
+  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!!
+
+  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 ) & 0x07;
+
+    // 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));
+}
+
+/****************************************************************************/
+
+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) );
+  }
+
+  // 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) );
+  }
+
+  //
+  // 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 & 0x07 ) );
+  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, 0x07);
+  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)) ;
+  
+  // 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( 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);
+}
+
+// vim:ai:cin:sts=2 sw=2 ft=cpp
+

diff -r 5be2682710c6 -r 75a5b58b2338 RF24.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/RF24.h	Mon Mar 25 07:35:02 2019 +0000
@@ -0,0 +1,829 @@
+/*
+ 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
+ */
+
+#ifndef __RF24_H__
+#define __RF24_H__
+
+#include "mbed.h"
+#include <RF24_config.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:
+  uint8_t ce_pin; /**< "Chip Enable" pin, activates the RX or TX role */
+  uint8_t csn_pin; /**< SPI Chip select */
+  bool wide_band; /* 2Mbs data rate in use? */
+  bool p_variant; /* False for RF24L01 and true for RF24L01P */
+  uint8_t payload_size; /**< Fixed size of payloads */
+  bool ack_payload_available; /**< Whether there is an ack payload waiting */
+  bool dynamic_payloads_enabled; /**< Whether dynamic payloads are enabled. */ 
+  uint8_t ack_payload_length; /**< Dynamic size of pending ack payload. */
+  uint64_t pipe0_reading_address; /**< Last address set on pipe 0 for reading. */
+
+  DigitalOut do_csn;
+  DigitalOut do_ce;
+  SPI spi;
+  Timer timer;
+
+protected:
+  /**
+   * @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(int 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(int 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);
+
+  /**
+   * 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);
+
+  /**
+   * Empty the transmit buffer
+   *
+   * @return Current value of status register
+   */
+  uint8_t flush_tx(void);
+
+  /**
+   * Retrieve the current status of the chip
+   *
+   * @return Current value of status register
+   */
+  uint8_t get_status(void);
+
+  /**
+   * 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(Serial& serial, 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(Serial& serial, 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(Serial& serial, 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(Serial& serial, const char* name, uint8_t reg, uint8_t qty = 1);
+
+  /**
+   * 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);
+  /**@}*/
+
+public:
+  /**
+   * @name Primary public interface
+   *
+   *  These are the main methods you need to operate the chip
+   */
+  /**@{*/
+
+  /**
+   * 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 csn,
+                     PinName ce);
+
+  /**
+   * Begin operation of the chip
+   *
+   * Call this in setup(), before calling any other methods.
+   */
+  void begin(void);
+
+  /**
+   * Start listening on the pipes opened for reading.
+   *
+   * Be sure to call openReadingPipe() first.  Do not call write() while
+   * in this mode, without first calling stopListening().  Call
+   * isAvailable() to check for incoming traffic, and read() to get it.
+   */
+  void startListening(void);
+
+  /**
+   * Stop listening for incoming messages
+   *
+   * Do this before calling write().
+   */
+  void stopListening(void);
+
+  /**
+   * Write to the open writing pipe
+   *
+   * 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 60ms.
+   *
+   * 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.
+   *
+   * @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 write( const void* buf, uint8_t len );
+
+  /**
+   * Test whether there are bytes available to be read
+   *
+   * @return True if there is a payload available, false if none is
+   */
+  bool available(void);
+
+  /**
+   * Read the payload
+   *
+   * Return the last payload received
+   *
+   * 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.
+   *
+   * @param buf Pointer to a buffer where the data should be written
+   * @param len Maximum number of bytes to read into the buffer
+   * @return True if the payload was delivered successfully false if not
+   */
+  bool read( void* buf, uint8_t len );
+
+  /**
+   * Open a pipe for writing
+   *
+   * Only one pipe can be open at once, but you can change the pipe
+   * you'll listen to.  Do not call this while actively listening.
+   * Remember to stopListening() first.
+   *
+   * Addresses are 40-bit hex values, e.g.:
+   *
+   * @code
+   *   openWritingPipe(0xF0F0F0F0F0);
+   * @endcode
+   *
+   * @param address The 40-bit address of the pipe to open.  This can be
+   * any value whatsoever, as long as you are the only one writing to it
+   * and only one other radio is listening to it.  Coordinate these pipe
+   * addresses amongst nodes on the network.
+   */
+  void openWritingPipe(uint64_t address);
+
+  /**
+   * Open a pipe for reading
+   *
+   * Up to 6 pipes can be open for reading at once.  Open all the
+   * reading pipes, and then call startListening().
+   *
+   * @see openWritingPipe
+   *
+   * @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().
+   *
+   * @todo Enforce the restriction that pipes 1-5 must share the top 32 bits
+   *
+   * @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);
+
+  /**@}*/
+  /**
+   * @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 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, 0-127
+   */
+  void setChannel(uint8_t channel);
+
+  /**
+   * 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
+   *
+   * @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.
+   *
+   * @see examples/pingpair_pl/pingpair_pl.pde
+   */
+  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.
+   *
+   * @see examples/pingpair_pl/pingpair_dyn.pde
+   */
+  void enableDynamicPayloads(void);
+
+  /**
+   * 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.
+   * Relative mnemonics have been used to allow for future PA level
+   * changes. According to 6.5 of the nRF24L01+ specification sheet,
+   * they translate to: RF24_PA_MIN=-18dBm, RF24_PA_LOW=-12dBm,
+   * RF24_PA_MED=-6dBM, and RF24_PA_HIGH=0dBm.
+   *
+   * @param level Desired PA level.
+   */
+  void setPALevel( rf24_pa_dbm_e level ) ;
+
+  /**
+   * Fetches the current PA level.
+   *
+   * @return Returns a value from the rf24_pa_dbm_e enum describing
+   * the current PA setting. Please remember, all values represented
+   * by the enum mnemonics are negative dBm. See setPALevel for
+   * return value descriptions.
+   */
+  rf24_pa_dbm_e 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
+   *
+   * @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
+   *
+   * @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
+   *
+   */
+  void disableCRC( void ) ;
+
+  /**@}*/
+  /**
+   * @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
+   */
+  void printDetails(Serial& serial);
+
+  /**
+   * Enter low-power mode
+   *
+   * To return to normal power mode, either write() some data or
+   * startListening, or powerUp().
+   */
+  void powerDown(void);
+
+  /**
+   * Leave low-power mode - making radio more responsive
+   *
+   * To return to low power mode, call powerDown().
+   */
+  void powerUp(void) ;
+
+  /**
+   * Test whether there are bytes available to be read
+   *
+   * Use this version to discover on which pipe the message
+   * arrived.
+   *
+   * @param[out] pipe_num Which pipe has the payload available
+   * @return True if there is a payload available, false if none is
+   */
+  bool available(uint8_t* pipe_num);
+
+  /**
+   * 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 whatHappened()
+   *
+   * @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
+   */
+  void startWrite( const void* buf, uint8_t len );
+
+  /**
+   * 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.
+   *
+   * @warning According to the data sheet, only three of these can be pending
+   * at any time.  I have not tested this.
+   *
+   * @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().
+   *
+   * Call read() to retrieve the ack payload.
+   *
+   * @warning Calling this function clears the internal flag which indicates
+   * a payload is available.  If it returns true, you must read the packet
+   * out as the very next interaction with the radio, or the results are
+   * undefined.
+   *
+   * @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);
+
+  /**
+   * 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.
+   *
+   * @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; } 
+
+  /**@}*/
+};
+
+/**
+ * @example GettingStarted.pde
+ *
+ * This is an example which corresponds to my "Getting Started" blog post:
+ * <a style="text-align:center" href="http://maniacbug.wordpress.com/2011/11/02/getting-started-rf24/">Getting Started with nRF24L01+ on Arduino</a>. 
+ *
+ * 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 
+ * with the serial monitor and 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.
+ */
+
+/**
+ * @example nordic_fob.pde
+ *
+ * This is an example of how to use the RF24 class to receive signals from the
+ * Sparkfun Nordic FOB.  See http://www.sparkfun.com/products/8602 .
+ * Thanks to Kirk Mower for providing test hardware.
+ */
+
+/**
+ * @example led_remote.pde
+ *
+ * This is an example of how to use the RF24 class to control a remote
+ * bank of LED's using buttons on a remote control.
+ *
+ * Every time the buttons change on the remote, the entire state of
+ * buttons is send to the led board, which displays the state.
+ */
+
+/**
+ * @example pingpair.pde
+ *
+ * This is an example of how to use the RF24 class.  Write this sketch to two
+ * different nodes, connect the role_pin to ground on one.  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.
+ */
+
+/**
+ * @example pingpair_maple.pde 
+ *
+ * This is an example of how to use the RF24 class on the Maple.  For a more
+ * detailed explanation, see my blog post:
+ * <a href="http://maniacbug.wordpress.com/2011/12/14/nrf24l01-running-on-maple-3/">nRF24L01+ Running on Maple</a>
+ *
+ * It will communicate well to an Arduino-based unit as well, so it's not for only Maple-to-Maple communication.
+ * 
+ * Write this sketch to two different nodes,
+ * connect the role_pin to ground on one.  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.
+ */
+
+/**
+ * @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_pl.pde
+ *
+ * This is an example of how to do two-way communication without changing
+ * transmit/receive modes.  Here, a payload is set to the transmitter within
+ * the Ack packet of each transmission.  Note that the payload is set BEFORE
+ * the sender's message arrives.
+ */
+
+/**
+ * @example pingpair_irq.pde
+ *
+ * This is an example of how to user interrupts to interact with the radio.
+ * It builds on the pingpair_pl example, and uses ack payloads.
+ */
+
+/**
+ * @example pingpair_sleepy.pde
+ *
+ * This is an example of how to use the RF24 class to create a battery-
+ * efficient system.  It is just like the pingpair.pde example, but the
+ * ping node powers down the radio and sleeps the MCU after every
+ * ping/pong cycle.
+ */
+
+/**
+ * @example scanner.pde
+ *
+ * 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 Driver for nRF24L01(+) 2.4GHz Wireless Transceiver
+ *
+ * @section Goals Design Goals
+ * 
+ * This library is designed to be...
+ * @li Maximally compliant with the intended operation of the chip
+ * @li Easy for beginners to use
+ * @li Consumed with a public interface that's similiar to other Arduino standard libraries
+ *
+ * @section News News
+ * 
+ * NOW COMPATIBLE WITH ARDUINO 1.0 - The 'master' branch and all examples work with both Arduino 1.0 and earlier versions.  
+ * Please <a href="https://github.com/maniacbug/RF24/issues/new">open an issue</a> if you find any problems using it with any version of Arduino.
+ *
+ * NOW COMPATIBLE WITH MAPLE - RF24 has been tested with the 
+ * <a href="http://leaflabs.com/store/#Maple-Native">Maple Native</a>, 
+ * and should work with any Maple board.  See the pingpair_maple example.
+ * Note that only the pingpair_maple example has been tested on Maple, although
+ * the others can certainly be adapted.
+ *
+ * @section Useful Useful References
+ * 
+ * Please refer to:
+ *
+ * @li <a href="http://maniacbug.github.com/RF24/">Documentation Main Page</a>
+ * @li <a href="http://maniacbug.github.com/RF24/classRF24.html">RF24 Class Documentation</a>
+ * @li <a href="https://github.com/maniacbug/RF24/">Source Code</a>
+ * @li <a href="https://github.com/maniacbug/RF24/archives/master">Downloads Page</a>
+ * @li <a href="http://www.nordicsemi.com/files/Product/data_sheet/nRF24L01_Product_Specification_v2_0.pdf">Chip Datasheet</a>
+ *
+ * This chip uses the SPI bus, plus two chip control pins.  Remember that pin 10 must still remain an output, or
+ * the SPI hardware will go into 'slave' mode.
+ *
+ * @section More More Information
+ *
+ * @subpage FAQ
+ *
+ * @section Projects Projects
+ *
+ * Stuff I have built with RF24
+ *
+ * <img src="http://farm7.staticflickr.com/6044/6307669179_a8d19298a6_m.jpg" width="240" height="160" alt="RF24 Getting Started - Finished Product">
+ *
+ * <a style="text-align:center" href="http://maniacbug.wordpress.com/2011/11/02/getting-started-rf24/">Getting Started with nRF24L01+ on Arduino</a> 
+ *
+ * <img src="http://farm8.staticflickr.com/7159/6645514331_38eb2bdeaa_m.jpg" width="240" height="160" alt="Nordic FOB and nRF24L01+">
+ *
+ * <a style="text-align:center" href="http://maniacbug.wordpress.com/2012/01/08/nordic-fob/">Using the Sparkfun Nordic FOB</a> 
+ *
+ * <img src="http://farm7.staticflickr.com/6097/6224308836_b9b3b421a3_m.jpg" width="240" height="160" alt="RF Duinode V3 (2V4)">
+ *
+ * <a href="http://maniacbug.wordpress.com/2011/10/19/sensor-node/">Low-Power Wireless Sensor Node</a>
+ *
+ * <img src="http://farm8.staticflickr.com/7012/6489477865_b56edb629b_m.jpg" width="240" height="161" alt="nRF24L01+ connected to Leaf Labs Maple Native">
+ *
+ * <a href="http://maniacbug.wordpress.com/2011/12/14/nrf24l01-running-on-maple-3/">nRF24L01+ Running on Maple</a>
+ */
+
+#endif // __RF24_H__
+// vim:ai:cin:sts=2 sw=2 ft=cpp
+

diff -r 5be2682710c6 -r 75a5b58b2338 RF24_config.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/RF24_config.h	Mon Mar 25 07:35:02 2019 +0000
@@ -0,0 +1,18 @@
+
+/*
+ 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.
+ */
+
+#ifndef __RF24_CONFIG_H__
+#define __RF24_CONFIG_H__
+
+
+
+#define _BV(x) (1<<(x))
+
+#endif // __RF24_CONFIG_H__
+// vim:ai:cin:sts=2 sw=2 ft=cpp

diff -r 5be2682710c6 -r 75a5b58b2338 main.cpp
--- a/main.cpp	Wed Jan 19 23:53:19 2011 +0000
+++ b/main.cpp	Mon Mar 25 07:35:02 2019 +0000
@@ -1,75 +1,42 @@
 #include "mbed.h"
-#include "nRF24L01P.h"
+#include "nRF24L01.h"
+#include "RF24.h"
 
-Serial pc(USBTX, USBRX); // tx, rx
+//Serial pc(USBTX, USBRX); // tx, rx
+Serial pc(PA_9, PA_10);
+
+RF24 radio(PB_5, PB_4, PB_3, PB_7, PB_6); // mosi, miso, sck, csn, ce
 
-nRF24L01P my_nrf24l01p(p5, p6, p7, p8, p9, p10);    // mosi, miso, sck, csn, ce, irq
+struct MyData {
+  float voltage;
+  float current;
+};
+
+MyData data;
 
-DigitalOut myled1(LED1);
-DigitalOut myled2(LED2);
+void resetData() 
+{
+  data.voltage = 12;
+  data.current = 34;
+}
+
+const uint64_t pipeOut =  0xE8E8F0F0E1LL;
 
 int main() {
-
-// The nRF24L01+ supports transfers from 1 to 32 bytes, but Sparkfun's
-//  "Nordic Serial Interface Board" (http://www.sparkfun.com/products/9019)
-//  only handles 4 byte transfers in the ATMega code.
-#define TRANSFER_SIZE   4
-
-    char txData[TRANSFER_SIZE], rxData[TRANSFER_SIZE];
-    int txDataCnt = 0;
-    int rxDataCnt = 0;
-
-    my_nrf24l01p.powerUp();
+    
+    resetData();  
+    
+    radio.begin();
+    radio.setAutoAck(false);
+    radio.setDataRate(RF24_250KBPS);
+    radio.openWritingPipe(pipeOut);
 
-    // Display the (default) setup of the nRF24L01+ chip
-    pc.printf( "nRF24L01+ Frequency    : %d MHz\r\n",  my_nrf24l01p.getRfFrequency() );
-    pc.printf( "nRF24L01+ Output power : %d dBm\r\n",  my_nrf24l01p.getRfOutputPower() );
-    pc.printf( "nRF24L01+ Data Rate    : %d kbps\r\n", my_nrf24l01p.getAirDataRate() );
-    pc.printf( "nRF24L01+ TX Address   : 0x%010llX\r\n", my_nrf24l01p.getTxAddress() );
-    pc.printf( "nRF24L01+ RX Address   : 0x%010llX\r\n", my_nrf24l01p.getRxAddress() );
-
-    pc.printf( "Type keys to test transfers:\r\n  (transfers are grouped into %d characters)\r\n", TRANSFER_SIZE );
-
-    my_nrf24l01p.setTransferSize( TRANSFER_SIZE );
-
-    my_nrf24l01p.setReceiveMode();
-    my_nrf24l01p.enable();
+    radio.printDetails(pc);
 
     while (1) {
-
-        // If we've received anything over the host serial link...
-        if ( pc.readable() ) {
-
-            // ...add it to the transmit buffer
-            txData[txDataCnt++] = pc.getc();
-
-            // If the transmit buffer is full
-            if ( txDataCnt >= sizeof( txData ) ) {
-
-                // Send the transmitbuffer via the nRF24L01+
-                my_nrf24l01p.write( NRF24L01P_PIPE_P0, txData, txDataCnt );
-
-                txDataCnt = 0;
-            }
-
-            // Toggle LED1 (to help debug Host -> nRF24L01+ communication)
-            myled1 = !myled1;
-        }
-
-        // If we've received anything in the nRF24L01+...
-        if ( my_nrf24l01p.readable() ) {
-
-            // ...read the data into the receive buffer
-            rxDataCnt = my_nrf24l01p.read( NRF24L01P_PIPE_P0, rxData, sizeof( rxData ) );
-
-            // Display the receive buffer contents via the host serial link
-            for ( int i = 0; rxDataCnt > 0; rxDataCnt--, i++ ) {
-
-                pc.putc( rxData[i] );
-            }
-
-            // Toggle LED2 (to help debug nRF24L01+ -> Host communication)
-            myled2 = !myled2;
-        }
+    
+        radio.write( (char*)&data, sizeof(data) );
+        
+        //wait( 0.01 );
     }
 }

diff -r 5be2682710c6 -r 75a5b58b2338 mbed.bld
--- a/mbed.bld	Wed Jan 19 23:53:19 2011 +0000
+++ b/mbed.bld	Mon Mar 25 07:35:02 2019 +0000
@@ -1,1 +1,1 @@
-http://mbed.org/users/mbed_official/code/mbed/builds/e2ac27c8e93e
+http://mbed.org/users/mbed_official/code/mbed/builds/d75b3fe1f5cb
\ No newline at end of file

diff -r 5be2682710c6 -r 75a5b58b2338 nRF24L01.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/nRF24L01.h	Mon Mar 25 07:35:02 2019 +0000
@@ -0,0 +1,125 @@
+/*
+    Copyright (c) 2007 Stefan Engelke <mbox@stefanengelke.de>
+
+    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.
+*/
+
+/* Memory Map */
+#define 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 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
+
+/* P model bit Mnemonics */
+#define RF_DR_LOW   5
+#define RF_DR_HIGH  3
+#define RF_PWR_LOW  1
+#define RF_PWR_HIGH 2

diff -r 5be2682710c6 -r 75a5b58b2338 nRF24L01P.lib
--- a/nRF24L01P.lib	Wed Jan 19 23:53:19 2011 +0000
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,1 +0,0 @@
-http://mbed.org/users/Owen/code/nRF24L01P/#8ae48233b4e4