nRF24L01 send and receive data at the same time

hi i'm mattia,
i think topic interesting , useful because didn't find informations it.
i have 2 arduino uno , 2 nrf24l01, , want sand , receive data @ same time. have problems when receiver changes mode , have send response message

this sketch of sending arduino

code: [select]


#include <wire.h>

#include <nrf24l01.h>                    
#include <rf24.h>
#include <spi.h>

#define in 1
#define out 2

int role = out;
bool answer = false;

rf24 radio(7, 8);                                     //nrf address

const byte txaddr[6] = "00001";
const byte rxaddr[6] = "00002";

int yellow = 3, red = 4;

int const x = 1;
int pin = 6, button;

char ans[5];
int anslen = sizeof(ans);



void setup() {

  serial.begin(9600);

  radio.begin();
  radio.setautoack(1);                    // ensure autoack enabled
  radio.enableackpayload();               // allow optional ack payloads
  radio.setretries(0, 15);                // smallest time between retries, max no. of retries
  radio.setpayloadsize(1);                // here sending 1-byte payloads test call-response speed
  radio.openwritingpipe(txaddr);        // both radios listen on same pipes default, , switch when writing
  //radio.openreadingpipe(1, rxaddr);
  radio.startlistening();                 // start listening
  radio.printdetails();
  //***transmitting data

  /*radio.begin();

    radio.openwritingpipe(rxaddr);
    radio.openreadingpipe(0, rxaddr);

    //radio.enableackpayload();

    radio.setretries(3, 5);*/

  pinmode(yellow, output);                //led giallo
  pinmode(red, output);                   //led rosso
  pinmode(pin, input_pullup);             //pulsante
}



void loop () {

  if (role == out)                        //role stabilisce se arduino trasmette o riceve
    radio.stoplistening();                // in qusto sta inviando

  button = digitalread(pin);
  delay(200);

  if (!button) {                            //quando viene premuto il pulsante

    if (radio.write(&x, sizeof(x)))           // viene semplicemente inviato x e viene fatto il controllo sull'effettivo invio con un if
      serial.println("inviato\n\n");

    while ( !answer) {                      //answer è una variabile booleana che verifica se la risposta è arrivata
      serial.println(answer);
      ledy();  

      if (role == out)                      // cambia role, in ricevente
        change_mode(in);

      if (radio.available()) {
        serial.println("ricevuto");            

        radio.read(ans, anslen);            //riceve il messaggio di ritorno dall'altro arduino

        if (strcmp(ans, "ok") == 0) {         // lo confronta con il messaggio che dovrebbe essere
          ledr();
          answer = true;                  //cambia la variabile per uscire dal while
        }
      }
    }

    answer = false;                   // ritorno alle condizioni iniziali
    change_mode(out);


  }

}


void change_mode(int x) {             // funzione che scambia ruoli fra ricevente e trasmettente
  
  switch (x) {
    case in:
      role = in;
      radio.openreadingpipe(1, rxaddr);
      radio.startlistening();
      serial.println ("sto ricevendo");
      break;

    case out:
      role = out;
      radio.stoplistening();
      radio.openwritingpipe(txaddr);
      break;
  }

  return;

}

void ledy() {

  digitalwrite(red, low);
  digitalwrite(yellow, high);
  delay(300);
  digitalwrite(yellow, low);
  delay(300);
  return;
}

void ledr() {

  digitalwrite(yellow, low);
  digitalwrite(red, high);
  delay(1500);
  return;
}




this sketch of receiving arduino

code: [select]


#include <wire.h>

#include <nrf24l01.h>
#include <rf24.h>
#include <spi.h>

#define in 1
#define out 2

int role = in;

char ackmex[] = "ok";
char answer[5];

rf24 radio(7, 8);                                     //nrf address

const byte rxaddr[6] = "00001";
const byte txaddr[6] = "00002";

int yellow = 3, green = 4;

int const x = 1;






void setup() {
  serial.begin(9600);

  pinmode(yellow, output);
  pinmode(green, output);

  radio.begin();
  radio.setautoack(1);                    // ensure autoack enabled
  radio.enableackpayload();               // allow optional ack payloads
  radio.setretries(0, 15);                // smallest time between retries, max no. of retries
  radio.setpayloadsize(1);                // here sending 1-byte payloads test call-response speed
  //radio.openwritingpipe(rxaddr);        // both radios listen on same pipes default, , switch when writing
  radio.openreadingpipe(1, rxaddr);
  radio.startlistening();                 // start listening
  radio.printdetails();

  /*
    radio.begin();

    radio.openwritingpipe(rxaddr);
    radio.openreadingpipe(1, rxaddr);

    radio.setretries(3, 5);

    //radio.enableackpayload();

    //radio.writeackpayload(0, ack, acklen);

    serial.println("sto ricevendo");

    radio.startlistening();
  */



}



void loop() {

  digitalwrite(yellow, low);
  digitalwrite(green, low);

  if (radio.available()) {            //si prepara ricevere il messaggio

    serial.println("ricevuto");

    ledg();

    radio.read(answer, sizeof(answer));         //legge il valore

    if (role == in)         //cambia il suo ruolo in trasmettente
      change_mode(out);

    serial.println(ackmex);



    radio.write(ackmex, sizeof(ackmex));        //invia il segnale di risposta



    delay(100);

    if (role == out)
      change_mode(in);              //cambia il valore in ricevente, = condizioni iniziali

  }
  ledy();


}

void change_mode(int x) {           //funzione per cambiare da ricevente trasmettente

  switch (x) {
    case in:
      role = in;
      radio.openreadingpipe(1, rxaddr);
      radio.startlistening();
      serial.println("sto ricevendo");
      break;

    case out:
      role = out;
      radio.stoplistening();
      radio.openwritingpipe(txaddr);
      serial.println("sto trasmettndo");
      break;
  }

  return;

}

void ledg() {

  digitalwrite(yellow, low);
  digitalwrite(green, high);
  delay(3000);
  return;
}

void ledy() {
  digitalwrite(green, low);
  digitalwrite(yellow, high);
  delay(300);
  digitalwrite(yellow, low);
  delay(300);
  return;
}



please edit original post , correct reference nrf24l01 in title.

you can't send , receive @ same time - although can close together.

you need tell problem having. have managed communication working?



i got nrf24s working tutorial

i suggest use tmrh20 version of rf24 library - solves problems maniacbug version

the pair of programs in this link may useful.

...r

Arduino Forum > Using Arduino > Networking, Protocols, and Devices (Moderator: fabioc84) > nRF24L01 send and receive data at the same time

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