Trying to find MAC address on ESP32 and failing

Projects Networking, Protocols, and Devices
1

Hello everyone,

I'm having a persistent issue where I cannot get the MAC address from any of my ESP32 boards. I'm hoping someone has seen this specific problem before.

The Problem:
When I run a basic sketch to get the MAC address, the Serial Monitor always outputs 00:00:00:00:00:00. This happens even on a known-good board that can run other complex sketches (like controlling a FastLED strip).

The Code:
This is the minimal code I am using for the test. I have also tried the esp_base_mac_addr_get() function, but the IDE gives a "not declared in this scope" error.

codeC++

#include "WiFi.h"

void setup(){
  Serial.begin(115200);
  
  WiFi.mode(WIFI_STA);
  
  Serial.println();
  Serial.print("My MAC Address is: ");
  Serial.println(WiFi.macAddress());
}

void loop(){
}

The Output:
This is the full output from the Serial Monitor after pressing the RST button:

codeCode

ets Jun  8 2016 00:22:57

rst:0x1 (POWERON_RESET),boot:0x13 (SPI_FAST_FLASH_BOOT)
configsip: 0, SPIWP:0xee
clk_drv:0x00,q_drv:0x00,d_drv:0x00,cs0_drv:0x00,hd_drv:0x00,wp_drv:0x00
mode:DIO, clock div:1
load:0x3fff0030,len:4980
load:0x40078000,len:16612
load:0x40080400,len:3480
entry 0x400805b4

My MAC Address is: 00:00:00:00:00:00

What I Have Already Tried:

  • I have tested this on two different ESP32 boards.

  • I have used multiple different USB cables and multiple different USB ports on my computer.

  • In the Arduino IDE Boards Manager, I have completely uninstalled and reinstalled the "esp32 by Espressif Systems" package (using version 3.3.3).

  • I have confirmed that "ESP32 Dev Module" is selected under the Tools > Board menu.

  • I have confirmed the correct COM port is selected and that the upload completes successfully.

My System Information:

  • *Operating System: (Windows 11) *

  • *Arduino IDE Version: (2.3.6) *

Does anyone have any idea what could be causing the Wi-Fi hardware to fail to initialize in this way across multiple boards? Thank you in advance for your help.

2

You might want to check the outstanding issues on the ESP32 core for previous reports and workaround or solutions.

1 Like
3

I have had similar problems, but using the following may help to show MAC address in the Serial Monitor, works for me on ESP32:

  auto stringhexcode = Network.macAddress();
  Serial.println("Uppercase MAC address=");
    stringhexcode.toUpperCase();
  Serial.println(stringhexcode);
4

Sometimes you need a small delay to allow wifi to initialize

#include <WiFi.h>

void setup(){

 Serial.begin(115200);

  WiFi.mode(WIFI_MODE_STA);
  while (WiFi.status()==WL_STOPPED){}
  Serial.print("My MAC Address is: ");
  Serial.println(WiFi.macAddress());

}

void loop()
{

}