serialDiscord.ino

/*
  Use a ESP32 as a Discord WebHook Serial "Modem"
  If you use an 5v Microcontroller you will need to make a voltage divider using resistor (or a level shifter)
  https://forum.arduino.cc/t/arduino-uno-serial-communication-with-esp32-using-voltage-divider/667516/14

*/

#include <Discord_WebHook.h>

Discord_Webhook discord; // Create a Discord_Webhook object
// How to get the Webhook URL
// https://support.discord.com/hc/en-us/articles/228383668-Intro-to-Webhooks
String DISCORD_WEBHOOK = "https://discord.com/api/webhooks/id/token";

void setup() {
  Serial.begin(115200);
  discord.begin(DISCORD_WEBHOOK); // Initialize the Discord_Webhook object
  discord.addWiFi("ssid","password"); // Add WiFi credentials (you can add multiples WiFi SSID)
  discord.connectWiFi(); // Connect to WiFi
}

void loop() {
  // If a message is received on the Serial Port (TX/RX)
  while (Serial.available() > 0) {
    //Read it as a String until the newline
    String command = Serial.readStringUntil('\n');

    // Check if the message start with message:
    if(command.indexOf("message:") == 0){
      // Remove message: from the String
      String message = command.substring(8);
      Serial.println("[SERIAL] Message: " + message);
      
      //Send the message
      discord.send(message);

    } else {
      Serial.println("[SERIAL] Invalid command, for example use: message:Hello World");
    }
  }
}