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

This is an example of how to use payloads of a varying (dynamic) size on Linux.

/*
TMRh20 2014 - Optimized RF24 Library Fork
*/
#include <cstdlib>
#include <iostream>
#include <sstream>
#include <string>
#include "./RF24.h"
using namespace std;
//
// Hardware configuration
// Configure the appropriate pins for your connections
/****************** Raspberry Pi ***********************/
// Radio CE Pin, CSN Pin, SPI Speed
// See http://www.airspayce.com/mikem/bcm2835/group__constants.html#ga63c029bd6500167152db4e57736d0939 and the related enumerations for pin information.
// Setup for GPIO 22 CE and CE0 CSN with SPI Speed @ 4Mhz
//RF24 radio(RPI_V2_GPIO_P1_22, BCM2835_SPI_CS0, BCM2835_SPI_SPEED_4MHZ);
// NEW: Setup for RPi B+
//RF24 radio(RPI_BPLUS_GPIO_J8_15,RPI_BPLUS_GPIO_J8_24, BCM2835_SPI_SPEED_8MHZ);
// Setup for GPIO 15 CE and CE0 CSN with SPI Speed @ 8Mhz
RF24 radio(RPI_V2_GPIO_P1_15, RPI_V2_GPIO_P1_24, BCM2835_SPI_SPEED_8MHZ);
/*** RPi Alternate ***/
//Note: Specify SPI BUS 0 or 1 instead of CS pin number.
// See http://tmrh20.github.io/RF24/RPi.html for more information on usage
//RPi Alternate, with MRAA
//RF24 radio(15,0);
//RPi Alternate, with SPIDEV - Note: Edit RF24/arch/BBB/spi.cpp and set 'this->device = "/dev/spidev0.0";;' or as listed in /dev
//RF24 radio(22,0);
/****************** Linux (BBB,x86,etc) ***********************/
// See http://tmrh20.github.io/RF24/pages.html for more information on usage
// See http://iotdk.intel.com/docs/master/mraa/ for more information on MRAA
// See https://www.kernel.org/doc/Documentation/spi/spidev for more information on SPIDEV
// Setup for ARM(Linux) devices like BBB using spidev (default is "/dev/spidev1.0" )
//RF24 radio(115,0);
//BBB Alternate, with mraa
// CE pin = (Header P9, Pin 13) = 59 = 13 + 46
//Note: Specify SPI BUS 0 or 1 instead of CS pin number.
//RF24 radio(59,0);
/**************************************************************/
// Radio pipe addresses for the 2 nodes to communicate.
const uint64_t pipes[2] = { 0xF0F0F0F0E1LL, 0xF0F0F0F0D2LL };
const int min_payload_size = 4;
const int max_payload_size = 32;
const int payload_size_increments_by = 1;
int next_payload_size = min_payload_size;
char receive_payload[max_payload_size+1]; // +1 to allow room for a terminating NULL char
int main(int argc, char** argv){
bool role_ping_out = 1, role_pong_back = 0;
bool role = 0;
// Print preamble:
cout << "RF24/examples/pingpair_dyn/\n";
// Setup and configure rf radio
radio.begin();
radio.enableDynamicPayloads();
radio.setRetries(5,15);
radio.printDetails();
/********* Role chooser ***********/
printf("\n ************ Role Setup ***********\n");
string input = "";
char myChar = {0};
cout << "Choose a role: Enter 0 for receiver, 1 for transmitter (CTRL+C to exit) \n>";
getline(cin,input);
if(input.length() == 1) {
myChar = input[0];
if(myChar == '0'){
cout << "Role: Pong Back, awaiting transmission " << endl << endl;
}else{ cout << "Role: Ping Out, starting transmission " << endl << endl;
role = role_ping_out;
}
}
/***********************************/
if ( role == role_ping_out ) {
radio.openWritingPipe(pipes[0]);
radio.openReadingPipe(1,pipes[1]);
} else {
radio.openWritingPipe(pipes[1]);
radio.openReadingPipe(1,pipes[0]);
radio.startListening();
}
// forever loop
while (1)
{
if (role == role_ping_out)
{
// The payload will always be the same, what will change is how much of it we send.
static char send_payload[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZ789012";
// First, stop listening so we can talk.
radio.stopListening();
// Take the time, and send it. This will block until complete
printf("Now sending length %i...",next_payload_size);
radio.write( send_payload, next_payload_size );
// Now, continue listening
radio.startListening();
// Wait here until we get a response, or timeout
unsigned long started_waiting_at = millis();
bool timeout = false;
while ( ! radio.available() && ! timeout )
if (millis() - started_waiting_at > 500 )
timeout = true;
// Describe the results
if ( timeout )
{
printf("Failed, response timed out.\n\r");
}
else
{
// Grab the response, compare, and send to debugging spew
uint8_t len = radio.getDynamicPayloadSize();
radio.read( receive_payload, len );
// Put a zero at the end for easy printing
receive_payload[len] = 0;
// Spew it
printf("Got response size=%i value=%s\n\r",len,receive_payload);
}
// Update size for next time.
next_payload_size += payload_size_increments_by;
if ( next_payload_size > max_payload_size )
next_payload_size = min_payload_size;
// Try again 1s later
delay(100);
}
//
// Pong back role. Receive each packet, dump it out, and send it back
//
if ( role == role_pong_back )
{
// if there is data ready
if ( radio.available() )
{
// Dump the payloads until we've gotten everything
uint8_t len;
while (radio.available())
{
// Fetch the payload, and see if this was the last one.
len = radio.getDynamicPayloadSize();
radio.read( receive_payload, len );
// Put a zero at the end for easy printing
receive_payload[len] = 0;
// Spew it
printf("Got payload size=%i value=%s\n\r",len,receive_payload);
}
// First, stop listening so we can talk
radio.stopListening();
// Send the final one back.
radio.write( receive_payload, len );
printf("Sent response.\n\r");
// Now, resume listening so we catch the next packets.
radio.startListening();
}
}
}
}