How to retrieve and format wifi MAC address in MicroPython on ESP32? - esp32

Question

I have the following MicroPython code running on an ESP32:
import network
wlan_sta = network.WLAN(network.STA_IF)
wlan_sta.active(True)
wlan_mac = wlan_sta.config('mac')
print("MAC Address:", wlan_mac) # Show MAC for peering
The output looks like this:
MAC Address: b'0\xae\xa4z\xa7$'
I would like to display it in the more familiar format of six pairs of hex digits, like this:
MAC Address: AABBCC112233
After searching for a solution on the internet, I've tried:
print("MAC Address:", str(wlan_mac)) but it displays the same as when not using str()
print("MAC Address:", hex(wlan_mac)) but it results in TypeError: can't convert bytes to int
print("MAC Address:", wlan_mac.hex()) but it says AttributeError: 'bytes' object has no attribute 'hex'
I am also a little suspicious of the bytes retrieved from wlan_sta.config('mac'). I would have expected something that looked more like b'\xaa\xbb\xcc\x11\x22\x33' instead of b'0\xae\xa4z\xa7$'. The z and the $ seem very out of place for something that should be hexadecimal and it seems too short for what should be six pairs of digits.
So my question is two-fold:
Am I using the correct method to get the MAC address?
If it is correct, how can I format it as six pairs of hex digits?

Answer 1

I am also a little suspicious of the bytes retrieved from wlan_sta.config('mac'). I would have expected something that looked more like b'\xaa\xbb\xcc\x11\x22\x33' instead of b'0\xae\xa4z\xa7$'. The z and the $ seem very out of place for something that should be hexadecimal and it seems too short for what should be six pairs of digits.
You're not getting back a hexadecimal string, you're getting a byte string. So if the MAC address contains the value 7A, then the byte string will contain z (which has ASCII value 122 (hex 7A)).
Am I using the correct method to get the MAC address?
You are!
If it is correct, how can I format it as six pairs of hex digits?
If you want to print the MAC address as a hex string, you can use the
ubinascii.hexlify method:
>>> import ubinascii
>>> import network
>>> wlan_sta = network.WLAN(network.STA_IF)
>>> wlan_sta.active(True)
>>> wlan_mac = wlan_sta.config('mac')
>>> print(ubinascii.hexlify(wlan_mac).decode())
30aea47aa724
Or maybe:
>>> print(ubinascii.hexlify(wlan_mac).decode().upper())
30AEA47AA724

Answer 2

You can use:
def wifi_connect(ssid, pwd):
sta_if = None
import network
sta_if = network.WLAN(network.STA_IF)
if not sta_if.isconnected():
print("connecting to network...")
sta_if.active(True)
sta_if.connect(ssid, pwd)
while not sta_if.isconnected():
pass
print("----------------------------------------")
print("network config:", sta_if.ifconfig())
print("----------------------------------------")
get_my_mac_addr(sta_if)
Then:
def get_my_mac_addr(sta_if):
import ubinascii
import network
wlan_mac = sta_if.config('mac')
my_mac_addr = ubinascii.hexlify(wlan_mac).decode()
my_mac_addr = format_mac_addr(my_mac_addr)
Then:
def format_mac_addr(addr):
mac_addr = addr
mac_addr = mac_addr.upper()
new_mac = ""
for i in range(0, len(mac_addr),2):
#print(mac_addr[i] + mac_addr[i+1])
if (i == len(mac_addr) - 2):
new_mac = new_mac + mac_addr[i] + mac_addr[i+1]
else:
new_mac = new_mac + mac_addr[i] + mac_addr[i+1] + ":"
print("----------------------------------------")
print("My MAC Address:" + new_mac)
print("----------------------------------------")
return new_mac
Return:
----------------------------------------
My MAC Address:xx:xx:xx:xx:xx:xx
----------------------------------------