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

Dec 2014 - TMRh20

This example demonstrates how to send multiple variables in a single payload and work with data. As usual, it is generally important to include an incrementing value like millis() in the payloads to prevent errors.

/*
* Getting Started example sketch for nRF24L01+ radios
* This is an example of how to send data from one node to another using data structures
* Updated: Dec 2014 by TMRh20
*/
#include <SPI.h>
#include "RF24.h"
byte addresses[][6] = {"1Node","2Node"};
/****************** User Config ***************************/
/*** Set this radio as radio number 0 or 1 ***/
bool radioNumber = 1;
/* Hardware configuration: Set up nRF24L01 radio on SPI bus plus pins 7 & 8 */
RF24 radio(7,8);
/**********************************************************/
// Used to control whether this node is sending or receiving
bool role = 0;
struct dataStruct{
unsigned long _micros;
float value;
}myData;
void setup() {
Serial.begin(115200);
Serial.println(F("RF24/examples/GettingStarted_HandlingData"));
Serial.println(F("*** PRESS 'T' to begin transmitting to the other node"));
radio.begin();
// Set the PA Level low to prevent power supply related issues since this is a
// getting_started sketch, and the likelihood of close proximity of the devices. RF24_PA_MAX is default.
radio.setPALevel(RF24_PA_LOW);
// Open a writing and reading pipe on each radio, with opposite addresses
if(radioNumber){
radio.openWritingPipe(addresses[1]);
radio.openReadingPipe(1,addresses[0]);
}else{
radio.openWritingPipe(addresses[0]);
radio.openReadingPipe(1,addresses[1]);
}
myData.value = 1.22;
// Start the radio listening for data
radio.startListening();
}
void loop() {
/****************** Ping Out Role ***************************/
if (role == 1) {
radio.stopListening(); // First, stop listening so we can talk.
Serial.println(F("Now sending"));
myData._micros = micros();
if (!radio.write( &myData, sizeof(myData) )){
Serial.println(F("failed"));
}
radio.startListening(); // Now, continue listening
unsigned long started_waiting_at = micros(); // Set up a timeout period, get the current microseconds
boolean timeout = false; // Set up a variable to indicate if a response was received or not
while ( ! radio.available() ){ // While nothing is received
if (micros() - started_waiting_at > 200000 ){ // If waited longer than 200ms, indicate timeout and exit while loop
timeout = true;
break;
}
}
if ( timeout ){ // Describe the results
Serial.println(F("Failed, response timed out."));
}else{
// Grab the response, compare, and send to debugging spew
radio.read( &myData, sizeof(myData) );
unsigned long time = micros();
// Spew it
Serial.print(F("Sent "));
Serial.print(time);
Serial.print(F(", Got response "));
Serial.print(myData._micros);
Serial.print(F(", Round-trip delay "));
Serial.print(time-myData._micros);
Serial.print(F(" microseconds Value "));
Serial.println(myData.value);
}
// Try again 1s later
delay(1000);
}
/****************** Pong Back Role ***************************/
if ( role == 0 )
{
if( radio.available()){
// Variable for the received timestamp
while (radio.available()) { // While there is data ready
radio.read( &myData, sizeof(myData) ); // Get the payload
}
radio.stopListening(); // First, stop listening so we can talk
myData.value += 0.01; // Increment the float value
radio.write( &myData, sizeof(myData) ); // Send the final one back.
radio.startListening(); // Now, resume listening so we catch the next packets.
Serial.print(F("Sent response "));
Serial.print(myData._micros);
Serial.print(F(" : "));
Serial.println(myData.value);
}
}
/****************** Change Roles via Serial Commands ***************************/
if ( Serial.available() )
{
char c = toupper(Serial.read());
if ( c == 'T' && role == 0 ){
Serial.print(F("*** CHANGING TO TRANSMIT ROLE -- PRESS 'R' TO SWITCH BACK"));
role = 1; // Become the primary transmitter (ping out)
}else
if ( c == 'R' && role == 1 ){
Serial.println(F("*** CHANGING TO RECEIVE ROLE -- PRESS 'T' TO SWITCH BACK"));
role = 0; // Become the primary receiver (pong back)
radio.startListening();
}
}
} // Loop