How to get MAC adderesses of the boards

An important step to set up our device is to get the MAC address of our microcontrollers. This is necessary to connect the boards using their wireless communication standard: esp-now. In this way our boards will know the “ID” of the board they have to connect with.

To obtain the MAC address of our boards we can upload a very simple code, the following one is for the D1 mini with the ESP8266 microcontroller:

#include <Arduino.h>
#include <ESP8266WiFi.h>

void setup() {
Serial.begin(115200);
WiFi.disconnect();
ESP.eraseConfig();

// Wifi STA Mode
WiFi.mode(WIFI_STA);

// Get Mac Add
Serial.println();
Serial.print("Mac Address: ");
Serial.print(WiFi.macAddress());
}


void loop() {
// the loop does nothing
}

This will print the mac address of the device on the serial monitor, which you can open by clicking on its icon on the top-right of the IDE, or by going to Tools -> Serial Monitor, or with the shortcut Ctrl + Maiusc + M.

In this case the MAC address is 48:55:19:C6:6E:30

since the network controller of the microcontrollers are managed differently due to the different hardware resources we have to repeat the process with the dongle board but with a slightly different code, since the board we are using is based on the ESP32:

#include <Arduino.h>
#include <WiFi.h>

void setup() {
Serial.begin(115200);

// Set device as a Wi-Fi Station
WiFi.mode(WIFI_STA);

// Get Mac Add
Serial.println();
Serial.print("Mac Address: ");
Serial.println(WiFi.macAddress());
}

void loop() {
// the loop does nothing
}

In this case the MAC address is 78:E3:6D:0B:24:04