Optimized High Speed NRF24L01+ Driver Class Documenation  V1.0
TMRh20 2014 - Optimized Fork of NRF24L01+ Driver

Update: TMRh20
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.
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

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.
Update 2014 - TMRh20
#include <SPI.h>
#include "nRF24L01.h"
#include "RF24.h"
#include "printf.h"
// Hardware configuration
RF24 radio(7,8); // Set up nRF24L01 radio on SPI bus plus pins 7 & 8
const short role_pin = 5; // sets the role of this unit in hardware. Connect to GND to be the 'pong' receiver
// Leave open to be the 'ping' transmitter
// Demonstrates another method of setting up the addresses
byte address[][5] = { 0xCC,0xCE,0xCC,0xCE,0xCC , 0xCE,0xCC,0xCE,0xCC,0xCE};
// Role management
// Set up role. This sketch uses the same software for all the nodes in this
// system. Doing so greatly simplifies testing. The hardware itself specifies
// which node it is.
// This is done through the role_pin
typedef enum { role_sender = 1, role_receiver } role_e; // The various roles supported by this sketch
const char* role_friendly_name[] = { "invalid", "Sender", "Receiver"}; // The debug-friendly names of those roles
role_e role; // The role of the current running sketch
static uint32_t message_count = 0;
/********************** Setup *********************/
void setup(){
pinMode(role_pin, INPUT); // set up the role pin
digitalWrite(role_pin,HIGH); // Change this to LOW/HIGH instead of using an external pin
delay(20); // Just to get a solid reading on the role pin
if ( digitalRead(role_pin) ) // read the address pin, establish our role
role = role_sender;
role = role_receiver;
Serial.print(F("\n\rRF24/examples/pingpair_irq\n\rROLE: "));
// Setup and configure rf radio
radio.enableAckPayload(); // We will be using the Ack Payload feature, so please enable it
radio.enableDynamicPayloads(); // Ack payloads are dynamic payloads
// Open pipes to other node for communication
if ( role == role_sender ) { // This simple sketch opens a pipe on a single address for these two nodes to
radio.openWritingPipe(address[0]); // communicate back and forth. One listens on it, the other talks to it.
radio.writeAckPayload( 1, &message_count, sizeof(message_count) ); // Add an ack packet for the next time around. This is a simple
radio.printDetails(); // Dump the configuration of the rf unit for debugging
attachInterrupt(0, check_radio, LOW); // Attach interrupt handler to interrupt #0 (using pin 2) on BOTH the sender and receiver
/********************** Main Loop *********************/
void loop() {
if (role == role_sender) { // Sender role. Repeatedly send the current time
unsigned long time = millis(); // Take the time, and send it.
Serial.print(F("Now sending "));
radio.startWrite( &time, sizeof(unsigned long) ,0);
delay(2000); // Try again soon
if(role == role_receiver){ // Receiver does nothing except in IRQ
/********************** Interrupt *********************/
void check_radio(void) // Receiver role: Does nothing! All the work is in IRQ
bool tx,fail,rx;
radio.whatHappened(tx,fail,rx); // What happened?
if ( tx ) { // Have we successfully transmitted?
if ( role == role_sender ){ Serial.println(F("Send:OK")); }
if ( role == role_receiver ){ Serial.println(F("Ack Payload:Sent")); }
if ( fail ) { // Have we failed to transmit?
if ( role == role_sender ){ Serial.println(F("Send:Failed")); }
if ( role == role_receiver ){ Serial.println(F("Ack Payload:Failed")); }
if ( rx || radio.available()){ // Did we receive a message?
if ( role == role_sender ) { // If we're the sender, we've received an ack payload
Serial.print(F("Ack: "));
if ( role == role_receiver ) { // If we're the receiver, we've received a time message
static unsigned long got_time; // Get this payload and dump it
radio.read( &got_time, sizeof(got_time) );
Serial.print(F("Got payload "));
radio.writeAckPayload( 1, &message_count, sizeof(message_count) ); // Add an ack packet for the next time around. This is a simple
++message_count; // packet counter