Posted by: @leonardo1123

@noweare IT WORKS! I added a 5-failure timeout for transmission that totally solved the problem.

Also check out your library documentation... you may well find member functions to consider in your design, such as: auto ack, crc check, etc...

Cheers.

Thanks for sticking with me through this thread, I'm off to try to make a rudimentary sonar, I shall return in another thread if need be!

Once again, because I don't think it could be enough, Thank you. 

I imagine what I need to do is either find a more concrete way to make sure their roles are opposite or else adding a way for them to be able to switch roles if their current role is failing but I don't know how I would implement that in a way that wouldn't leave it possible for both to flip from both false, to both true, etc. 

Attached is a picture of the serial monitor of one of the devices.

I'm super confused because the "reverse role" statement only happens when a transmission or reception occurs successfully, I don't know how they could be falling into the same role. 

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

RF24 radio(8, 10);

uint8_t address[] = {"1Node", "2Node"};
bool radioNumber = 0; // this is set to 1 on the other device
bool role = false;  // this is set to true on the other device
float payload = 0.0;

void setup() {

  Serial.begin(115200);

  radio.begin();
  radio.setPALevel(RF24_PA_LOW);
  radio.setPayloadSize(sizeof(payload));
  radio.openWritingPipe(address);
  radio.openReadingPipe(1, address);

} // setup

void loop() {
  if (role) {
    // This device is a TX node
    radio.stopListening();

    unsigned long start_timer = micros();
    bool report = radio.write(&payload, sizeof(float));
    unsigned long end_timer = micros();

    if (report) {
      Serial.print(F("Transmission successful! "));
      Serial.print(F("Time to transmit = "));
      Serial.print(end_timer - start_timer);
      Serial.print(F(" us. Sent: "));
      Serial.println(payload);
      payload += 0.01;

      role = !role;
    } else {
      Serial.println(F("Transmission failed or timed out"));
    }

    delay(1000); // slow transmissions down by 1 second

  } else {
    // This device is a RX node

    radio.startListening();
    uint8_t pipe;
    if (radio.available(&pipe)) {
      uint8_t bytes = radio.getPayloadSize();
      radio.read(&payload, bytes);
      Serial.print(F("Received "));
      Serial.print(bytes);
      Serial.print(F(" bytes on pipe "));
      Serial.print(pipe);
      Serial.print(F(": "));
      Serial.println(payload);

      role = !role;
    }
  } // role

} // loop

local is set to TX, remote is set to RX. So local sends something and if no error occurred local changes to RX.

When the remote RX recieves it changes to TX. So they go back and forth without them being in the same state i.e. both RX or TX

Thanks again for all the help.

I said strip-out but you can just start another project and copy the code from your current file to your new file. Then you'll end up with projects that do one thing and they can be used for future projects.

So I did what @noweare suggested and went at it on my own, and I think I'm headed in the right direction, but I could use a little help.

Basically, I'm setting both devices to always listen except when data has changed on their end, in that case, they should send it. Since one device is a joystick I'm not touching, and the other is a static number in place of an actual sensor, they should each try to send their thing once and then go back to listening, but I'm just not getting the results I was hoping for. 

I know it's a lot of text, so I really appreciate any and all help, this is about 3 new terrains I'm trying to navigate haha...

Here's the code for my car which has motors and will have a ping sensor:

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

// Motor A
#define enA 6
#define in1 7
#define in2 5

// Motor B
#define enB 3
#define in3 2
#define in4 4

#define SPEED_MIN 120
#define DEADZONE 6

int j_X = 0;
int j_Y = 0;

RF24 radio(8, 10);
uint8_t address[] = {"1Node", "2Node"};
bool radioNumber = 1;

uint8_t joystick;

uint8_t pipe;

bool oldForward = true;
bool forward = true;

int left_throttle = 0;
int right_throttle = 0;

int trueLeftSpeed = 0;
int trueRightSpeed = 0;

bool received = false;

void setForward() {
  forward = true;

  digitalWrite(in1, HIGH);
  digitalWrite(in2, LOW);

  digitalWrite(in3, HIGH);
  digitalWrite(in4, LOW);
}

void setBackward() {
  forward = false;

  digitalWrite(in1, LOW);
  digitalWrite(in2, HIGH);

  digitalWrite(in3, LOW);
  digitalWrite(in4, HIGH);
}

void setThrottle() {
  j_X = 2*joystick - 255;
  j_Y = 2*joystick - 255;

  if ((abs(j_X) > DEADZONE or abs(j_Y) > DEADZONE) and received) {
    if (forward != oldForward) {
      left_throttle = 0;
      right_throttle = 0;
      if (trueLeftSpeed == 0 and trueRightSpeed == 0) { oldForward = forward; }
    } else {
      if (j_Y > 0) {
        if (forward == oldForward) { setForward(); }
        left_throttle = map(j_Y, 0, 255, SPEED_MIN, 255);
      } else {
        if (forward == oldForward) { setBackward(); }
        left_throttle = map(-j_Y, 0, 255, SPEED_MIN, 255);
      }

      right_throttle = left_throttle;

      if (-j_X > 3*DEADZONE) {
        right_throttle = map(-j_X, 3*DEADZONE, 255, left_throttle, SPEED_MIN);
      } else {
        left_throttle = map(j_X, 3*DEADZONE, 255, right_throttle, SPEED_MIN);
      }

      if (right_throttle > 255) { right_throttle = 255; }
      if (left_throttle > 255) { left_throttle = 255; }
    }

  } else {
    forward = true;
    left_throttle = 0;
    right_throttle = 0;
  } 
}

void setTrueSpeed() {
  if (trueRightSpeed < right_throttle and trueRightSpeed < SPEED_MIN) {trueRightSpeed = SPEED_MIN; }
  if (trueRightSpeed > right_throttle and trueRightSpeed < SPEED_MIN) {trueRightSpeed = 0; }
  if (trueLeftSpeed < left_throttle and trueLeftSpeed < SPEED_MIN) {trueLeftSpeed = SPEED_MIN; }
  if (trueLeftSpeed > left_throttle and trueLeftSpeed < SPEED_MIN) {trueLeftSpeed = 0; }

  if (trueLeftSpeed < left_throttle) { trueLeftSpeed++; }
  if (trueLeftSpeed > left_throttle) { trueLeftSpeed--; }
  if (trueRightSpeed < right_throttle) { trueRightSpeed++; }
  if (trueRightSpeed > right_throttle) { trueRightSpeed--; }
}

void debugInfo() {
  Serial.print("Left Throttle: ");
  Serial.print(left_throttle); 
  Serial.print(", Right Throttle: ");
  Serial.print(right_throttle);
  Serial.print(", True Left: ");
  Serial.print(trueLeftSpeed);
  Serial.print(", True Right: ");
  Serial.print(trueRightSpeed); 
  Serial.print(", Forward?: ");
  Serial.print(forward); 
  Serial.print(", Old Forward?: ");
  Serial.println(oldForward); 
}

void setMotors() {
  analogWrite(enA, trueLeftSpeed);
  analogWrite(enB, trueRightSpeed);
}

void getJoystick() {
  uint8_t bytes = radio.getPayloadSize(); // get the size of the payload
  radio.read(&joystick, bytes); // fetch payload from FIFO
  received = true;
}

uint8_t oldSensors;
uint8_t sensors;

void sendSensors() {
  radio.stopListening(); // put radio in TX mode

  bool report = radio.write(&sensors, sizeof(sensors)); // transmit & save the report

  if (report) {
    Serial.print(F("Sensor 1: "));
    Serial.print(sensors); // print payload sent
    Serial.print(F(", Sensor 2: "));
    Serial.println(sensors);

    oldSensors = sensors;
    oldSensors = sensors;
  } else {
    Serial.println(F("Transmission failed or timed out")); // payload was not delivered
  }
  radio.startListening(); // put radio in RX mode
}


void setup() {

  Serial.begin(115200);

  radio.begin();

  radioNumber = 0;

  radio.setPALevel(RF24_PA_LOW); 
  radio.setPayloadSize(sizeof(joystick)); 
  radio.openWritingPipe(address); 
  radio.openReadingPipe(1, address);

  radio.stopListening();

  setForward();

  sensors = 5;
  sensors = 8;

} // setup

void loop() {
  radio.startListening(); 
  if (radio.available(&pipe)) { // is there a payload? get the pipe number that recieved it
    getJoystick();
    radio.stopListening();
    setThrottle();
  }
  setTrueSpeed();
  if (trueLeftSpeed != left_throttle or trueRightSpeed != right_throttle) {
    debugInfo();
  }
  setMotors();
  if (oldSensors != sensors or oldSensors != sensors) {
    sendSensors();
  }
} // loop

And here's my code for the controller, which has a joystick and will have a display:

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

#define JOYSTICK_X A0
#define JOYSTICK_Y A1

RF24 radio(8, 10); // using pin 7 for the CE pin, and pin 8 for the CSN pin

uint8_t address[] = {"1Node", "2Node"};

bool radioNumber = 1; // 0 uses address to transmit, 1 uses address to transmit

bool role = false; // true = TX role, false = RX role

uint8_t joystick;
uint8_t oldJoystick;

uint8_t pipe;

void readJoystick() {
  joystick = map(analogRead(JOYSTICK_X), 0, 1023, 0, 255);
  joystick = map(analogRead(JOYSTICK_Y), 0, 1023, 0, 255);
}

  void sendJoystick() {
  radio.stopListening(); // put radio in TX mode

  bool report = radio.write(&joystick, sizeof(joystick)); // transmit & save the report

  if (report) {
    Serial.print(F("Joystick_X: "));
    Serial.print(joystick); // print payload sent
    Serial.print(F(", Joystick_Y: "));
    Serial.println(joystick);

    oldJoystick = joystick;
    oldJoystick = joystick;
  } else {
    Serial.println(F("Transmission failed or timed out")); // payload was not delivered
  }
  radio.startListening(); // put radio in RX mode
}

uint8_t sensors;

void getSensors() {
  uint8_t bytes = radio.getPayloadSize(); // get the size of the payload
  radio.read(&sensors, bytes); // fetch payload from FIFO
}

void setup() {

  Serial.begin(115200);

  radio.begin();

  radio.setPALevel(RF24_PA_LOW);
  radio.setPayloadSize(sizeof(joystick));
  radio.openWritingPipe(address);
  radio.openReadingPipe(1, address); // using pipe 1

} // setup

void loop() {
  readJoystick();

  if (oldJoystick != joystick or oldJoystick != joystick) {
    sendJoystick();
  }

  radio.startListening(); 
  if (radio.available(&pipe)) { // is there a payload? get the pipe number that recieved it
    getSensors();
    radio.stopListening();
  }

} // loop