Every TRMNL has 2 immutable characteristics -- a Mac Address, and a Serial.
Mac Addresses are generated by our manufacturer, and Serial values are printed directly on the PCB (circuit board).
In some cases, TRMNL may need to know one of these values to help debug a connection issue. But instead of disassembling your device, we suggest looking up your Mac Address instead.
Option A - WiFi Router settings
Pending your local network setup, you may have access to a wireless router settings interface. If you're using TRMNL at home, this would show al ist of devices such as your phone, television, computers, and so on.
If you have access to this, look for a device whose name starts with "ESP_", followed by a few random characters. Select that device and you should see a "MAC" value such as AB:4D:CA:FF:Q1.
Option B - WiFi Portal Footer
Put your TRMNL in "pairing mode" by turning it on, waiting for it to boot, then holding the button on the back (next to the on/off switch) for 5-6 seconds.
Let go of the button, then wait for TRMNL to show a WiFi setup screen like this:
Connect to the WiFi network named "TRMNL," and you should see a screen like this:
Select your local network, input a password, then coick "Connect." Within 1-2 seconds you should see a grey footer, "Connecting to SSID, MAC address:"
This screen usually disappears after 2-3 seconds, so it's easiest if you take a screenshot when you see the grey bar. The MAC address will be at the bottom of the footer area.