ESP 32 Esp Now comunication

Question

I am trying to set up one way communication with esp now thrue arduino ide. I am not really a programmer so I found some code and explanations on youtube. But I am not able to make it work even though I have copyied the programme. Not sure what I supposed to do. I tried updating boards , different tutorials,tweaked settings and yet nothing seems to work.

Here is the code:

    //>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> One-way communication ESP32 Sender
/*
  Rui Santos
  Complete project details at https://RandomNerdTutorials.com/esp-now-two-way-communication-esp32/
  
  Permission is hereby granted, free of charge, to any person obtaining a copy
  of this software and associated documentation files.
  
  The above copyright notice and this permission notice shall be included in all
  copies or substantial portions of the Software.
*/

//----------------------------------------Load libraries
#include <esp_now.h>
#include <WiFi.h>
//----------------------------------------

uint8_t broadcastAddress[] = {0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF}; //--> REPLACE WITH THE MAC Address of your receiver / ESP32 Receiver.

//----------------------------------------Variables to accommodate the data to be sent.
int send_rnd_val_1;
int send_rnd_val_2;
//----------------------------------------

String success; //--> Variable to store if sending data was successful.

//----------------------------------------Structure example to send data
// Must match the receiver structure
typedef struct struct_message {
    int rnd_1;
    int rnd_2;
} struct_message;

struct_message send_Data; //--> Create a struct_message to send data.
//----------------------------------------

//++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Callback when data is sent
void OnDataSent(const uint8_t *mac_addr, esp_now_send_status_t status) {
  Serial.print("\r\nLast Packet Send Status:\t");
  Serial.println(status == ESP_NOW_SEND_SUCCESS ? "Delivery Success" : "Delivery Fail");
  if (status ==0){
    success = "Delivery Success :)";
  }
  else{
    success = "Delivery Fail :(";
  }
  Serial.println(">>>>>");
}
//++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

//++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ VOID SETUP
void setup() {
  Serial.begin(115200);
 
  WiFi.mode(WIFI_STA); //--> Set device as a Wi-Fi Station.

  //----------------------------------------Init ESP-NOW
  if (esp_now_init() != ESP_OK) {
    Serial.println("Error initializing ESP-NOW");
    return;
  }
  //----------------------------------------
  
  //----------------------------------------Once ESPNow is successfully Init, we will register for Send CB to
  // get the status of Trasnmitted packet
  esp_now_register_send_cb(OnDataSent);
  //----------------------------------------
  
  //----------------------------------------Register peer
  esp_now_peer_info_t peerInfo;
  memcpy(peerInfo.peer_addr, broadcastAddress, 6);
  peerInfo.channel = 0;  
  peerInfo.encrypt = false;
  //----------------------------------------
  
  //----------------------------------------Add peer        
  if (esp_now_add_peer(&peerInfo) != ESP_OK){
    Serial.println("Failed to add peer");
    return;
  }
  //----------------------------------------
}
//++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

//++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ VOID LOOP
void loop() {
  //----------------------------------------Set values to send
  send_rnd_val_1 = random(0, 255);
  send_rnd_val_2 = random(0, 255);
  send_Data.rnd_1 = send_rnd_val_1;
  send_Data.rnd_2 = send_rnd_val_2;
  //----------------------------------------
  
  Serial.println();
  Serial.print(">>>>> ");
  Serial.println("Send data");

  //----------------------------------------Send message via ESP-NOW
  esp_err_t result = esp_now_send(broadcastAddress, (uint8_t *) &send_Data, sizeof(send_Data));
   
  if (result == ESP_OK) {
    Serial.println("Sent with success");
  }
  else {
    Serial.println("Error sending the data");
  }
  //----------------------------------------
  
  delay(5000);
}
//++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
//<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<






//>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> One-way communication ESP32 Receiver
/*
  Rui Santos
  Complete project details at https://RandomNerdTutorials.com/esp-now-two-way-communication-esp32/
  
  Permission is hereby granted, free of charge, to any person obtaining a copy
  of this software and associated documentation files.
  
  The above copyright notice and this permission notice shall be included in all
  copies or substantial portions of the Software.
*/

//----------------------------------------Load libraries
#include <esp_now.h>
#include <WiFi.h>
//----------------------------------------

//----------------------------------------Define variables to store incoming readings
int receive_rnd_val_1;
int receive_rnd_val_2;
//----------------------------------------

//----------------------------------------Structure example to receive data
// Must match the sender structure
typedef struct struct_message {
    int rnd_1;
    int rnd_2;
} struct_message;

struct_message receive_Data; //--> Create a struct_message to receive data.
//----------------------------------------

//++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Callback when data is received
void OnDataRecv(const uint8_t * mac, const uint8_t *incomingData, int len) {
  memcpy(&receive_Data, incomingData, sizeof(receive_Data));
  Serial.println();
  Serial.println("<<<<< Receive Data:");
  Serial.print("Bytes received: ");
  Serial.println(len);
  receive_rnd_val_1 = receive_Data.rnd_1;
  receive_rnd_val_2 = receive_Data.rnd_2;
  Serial.println("Receive Data: ");
  Serial.println(receive_rnd_val_1);
  Serial.println(receive_rnd_val_2);
  Serial.println("<<<<<");
}
//++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

//+

    +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ VOID SETUP
    void setup() {
      Serial.begin(115200);
      
      WiFi.mode(WIFI_STA); //--> Set device as a Wi-Fi Station
    
      //----------------------------------------Init ESP-NOW
      if (esp_now_init() != ESP_OK) {
        Serial.println("Error initializing ESP-NOW");
        return;
      }
      //----------------------------------------
      
      esp_now_register_recv_cb(OnDataRecv); //--> Register for a callback function that will be called when data is received
    }
    //++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
    
    //++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ VOID LOOP
    void loop() {
      
    }
    //++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
    //<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<

It downloads normally on to an ESP but it is not able to "Add pear"¨

Could anybody help please?

Answer 1

Looks like you forgot to update the broadcast MAC Address in your code (line 18). Recommend you update that and re-try.