Serial communication between ESP8266 and Arduino Mega

Projects Programming
1

Hi all.
8266_22_1_25.ino (2.2 KB)
Mega22_1_25.ino (2.9 KB)

I have a project that I send data (Digital) from a touch screen espnow to an esp8266 and from the esp8266 communicate via serial to the Mega 2560. I do get the data to read as expected on the esp8266 but the data on the Mega is raw data only. I fail to get the data in the ("1", "0" and digital) format. It's probably a small issue but hope somebody can help me out. The touch screen code is too big to print but the data received by the esp8266 is all good.

/ Define the data structure
typedef struct {
  int xval;
  int yval;
  int x;
  int y;
  float Slider1;
  float Slider2;
  int Value_SelectC;
  int Value_SelectCsharp;
  int Value_SelectA;
  int Value_SelectB;
  int Value_SelectBb;
  int Value_SelectD;
  int Value_SelectFb;
  int Value_SelectE;
  int Value_SelectFsharp;
  int Value_SelectG;
  float Slider_LUP;
  float Slider_LL;
  float Slider_LR;
  float Slider_RR;
  float Slider_RL;
  int Value_AutoAdjust;
  int Value_StringUP;
  int Value_StringDOWN;
  int Value_String1;
  int Value_String2;
  int Value_String3;
  int Value_String4;
  int Value_String5;
  int Value_String6;
  int Value_String7;
  int Value_String8;
  int Value_String9;
  int Value_String10;
  int Value_String11;
  int Value_String12;
} struct_message;

// Create a variable for the data structure
struct_message myData1;

void setup() {
  Serial.begin(9600);  // Debug serial
  Serial1.begin(9600);   // Communication with ESP8266
  Serial.println("Arduino Mega is ready to receive data from ESP8266");

  // Initialize motor control pins
  pinMode(9, OUTPUT);   // Motor direction pin
  pinMode(10, OUTPUT);  // Motor enable pin
  digitalWrite(9, LOW); // Ensure motor is stopped
  digitalWrite(10, LOW);
}

void loop() {

  // Check if data is available from ESP8266
  if (Serial1.available()) {
    String receivedData = "";  // Variable to store incoming data

    // Read data until a newline or timeout
    while (Serial1.available()) {
      char incomingChar = Serial1.read();
      if (incomingChar == '\n') break; // End of message
      receivedData += incomingChar;
    }

    // Parse received data into the structure
    if (receivedData.length() > 0) {
      Serial.println("Data received from ESP8266:");
      Serial.println(receivedData);

      // Parse the structure
     sscanf(receivedData.c_str(), "%d,%d,%d", 
            &myData1.Value_StringUP, 
            &myData1.Value_StringDOWN, 
            &myData1.Value_String1);

      // Debug parsed values
      Serial.print("Value_StringUP: ");
      Serial.println(myData1.Value_StringUP);
      Serial.print("Value_StringDOWN: ");
      Serial.println(myData1.Value_StringDOWN);
      Serial.print("Value_String1: ");
      Serial.println(myData1.Value_String1);

      // Control the motor based on the received data
      if (myData1.Value_StringUP == 1 && myData1.Value_String1 == 1) {
        digitalWrite(9, HIGH);  // Set direction to forward
        digitalWrite(10, HIGH); // Enable motor
        Serial.println("Motor running forward");
      } else if (myData1.Value_StringDOWN == 1 && myData1.Value_String1 == 1) {
        digitalWrite(9, LOW);   // Set direction to reverse
        digitalWrite(10, HIGH); // Enable motor
        Serial.println("Motor running reverse");
      } else {
        digitalWrite(10, LOW);  // Stop the motor
        Serial.println("Motor stopped");
      }
    }
  }


#include <ESP8266WiFi.h>
#include <espnow.h>

// Define data structure
typedef struct {
  int xval;
  int yval;
  int x;
  int y;
  float Slider1;
  float Slider2;
  int Value_SelectC;
  int Value_SelectCsharp;
  int Value_SelectA;
  int Value_SelectB;
  int Value_SelectBb;
  int Value_SelectD;
  int Value_SelectFb;
  int Value_SelectE;
  int Value_SelectFsharp;
  int Value_SelectG;
  float Slider_LUP;
  float Slider_LL;
  float Slider_LR;
  float Slider_RR;
  float Slider_RL;
  int Value_AutoAdjust;
  int Value_StringUP;
  int Value_StringDOWN;
  int Value_String1;
  int Value_String2;
  int Value_String3;
  int Value_String4;
  int Value_String5;
  int Value_String6;
  int Value_String7;
  int Value_String8;
  int Value_String9;
  int Value_String10;
  int Value_String11;
  int Value_String12;
} struct_message;

struct_message myData1;

void onDataRecv(uint8_t *mac, uint8_t *incomingData, uint8_t len) {
    memcpy(&myData1, incomingData, sizeof(myData1));
    Serial.println("Data received:");
    Serial.print("Value_StringUP: ");
    Serial.println(myData1.Value_StringUP);
    Serial.print("Value_StringDOWN: ");
    Serial.println(myData1.Value_StringDOWN);
    Serial.print("Value_String1: ");
    Serial.println(myData1.Value_String1);

    // Send data to Arduino Mega via Serial1
    Serial1.print(myData1.Value_StringUP);
    Serial1.print(",");
    Serial1.print(myData1.Value_StringDOWN);
    Serial1.print(",");
    Serial1.println(myData1.Value_String1);
}

void setup() {
    Serial.begin(115200);  // Debug serial
    Serial1.begin(9600);   // Communication with Arduino Mega (adjust baud rate as needed)

    // Initialize WiFi
    WiFi.mode(WIFI_STA);
    Serial.println(WiFi.macAddress());

    // Initialize ESP-NOW
    if (esp_now_init() != 0) {
        Serial.println("ESP-NOW initialization failed");
        return;
    }

    // Set ESP-NOW receive callback
    esp_now_set_self_role(ESP_NOW_ROLE_SLAVE);
    esp_now_register_recv_cb(onDataRecv);

    Serial.println("ESP-NOW receiver initialized");
}

void loop() {
    // Receiver is event-driven, so no need to handle logic here
}
2

Is it too difficult for you to post the program code right here on the forum?

3

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