Skip to main content
Arduino

Return to Question

added 354 characters in body
Source Link
StrudzonyWedrowiec
StrudzonyWedrowiec
  • 13
  • 2

EDIT: Ok after running sizeof(data) on both devices, I notice that structs have different size 4 bytes for arduino and 8 for raspberry. So change on raspberry side to

typedef struct{
  uint16_t id = 100;
  uintt16_t temperature = 100;
}
temp;

And this is working but, may I ask why int have various size on arduino and raspberry?

EDIT: Ok after running sizeof(data) on both devices, I notice that structs have different size 4 bytes for arduino and 8 for raspberry. So change on raspberry side to

typedef struct{
  uint16_t id = 100;
  uintt16_t temperature = 100;
}
temp;

And this is working but, may I ask why int have various size on arduino and raspberry?

Source Link
StrudzonyWedrowiec
StrudzonyWedrowiec
  • 13
  • 2

Sending data struct with 2 int fields from Arduino to Raspberry via NRF24L01

I'm trying to do wireless thermometer on max31865 arduino and nrf24l01 but I'm having problem sending whole data struct I can send int or char arrays but when I try to send whole struct I got output as

id: 131073 temperature: 0

Is there error in my code or there is some issue with differences in how arduino and raspberry store data? I don't really have experience in this so my question is how do I send struct that contain two fields of int or there is some better way? I need to transmit id and temperature in one package.

Transmitter code(Arduino)

#include <SPI.h>
#include "RF24.h"
#include <Adafruit_MAX31865.h>

#define RREF      430.0
#define RNOMINAL  100.0

typedef struct{
  int id = 100;
  int temperature = 100;
}
temp;

temp data;

bool radioNumber = 0;
int i =0;
Adafruit_MAX31865 thermo = Adafruit_MAX31865(10, 11, 12, 13);
RF24 radio(7,8);

byte addresses[][6] = {"1Node","2Node"};
bool role = 0;

void setup() {
  Serial.begin(115200);
  thermo.begin(MAX31865_3WIRE);
  radio.begin();
  radio.setChannel(125);
  radio.setPALevel(RF24_PA_MIN);
  radio.powerUp();
  radio.setDataRate(RF24_1MBPS);
  if(radioNumber){
    radio.openWritingPipe(addresses[1]);
    radio.openReadingPipe(1,addresses[0]);
  }else{
    radio.openWritingPipe(addresses[0]);
    radio.openReadingPipe(1,addresses[1]);
  }
  radio.stopListening();
}

void loop() {
      data.id = 1;
      data.temperature = 2;                                   
    //int temp = 2; //thermo.temperature(RNOMINAL, RREF);
    Serial.println(temp);   
    if (!radio.write( &data, sizeof(data) )){
        Serial.println(F("failed"));
     }
     delay(1000);
}

Receiver code(Raspberry pi b3+)

#include <cstdlib>
#include <iostream>
#include <sstream>
#include <string>
#include <unistd.h>
#include <RF24/RF24.h>

using namespace std;

typedef struct{
        int id = 99;   // debug value
        int temperature = 99;
}
temp;

RF24 radio(22,0);
temp data;

bool radioNumber = 1;
const uint8_t pipes[][6] = {"1Node", "2Node"};

int main(int argc, char** argv)
{
    radio.begin();
    radio.setChannel(125);
    radio.setPALevel(RF24_PA_MIN);
    radio.setDataRate(RF24_1MBPS);
    radio.setRetries(15, 15);
    radio.printDetails();
    if (!radioNumber) {
        radio.openWritingPipe(pipes[0]);
        radio.openReadingPipe(1, pipes[1]);
    } else {
        radio.openWritingPipe(pipes[1]);
        radio.openReadingPipe(1, pipes[0]);
    }

    radio.startListening();

    while (1) {
            if (radio.available()) {
                int tem = 0;
                while (radio.available()) {
                    radio.read(&data, sizeof(data));
                }
                cout << tem  << "  " << "id: "<< data.id<< " temperatura: " << data.temperature << endl;
                delay(925);

            }
        }
    return 0;
}