TRMNL 7.5" DIY Kit Setup Guide

Follow these steps to connect your TRMNL device to your BYOS server

Important: Your BYOS server URL is: https://your-app.vercel.app
You'll need this URL in Step 4.

Assemble Your Hardware

Connect the display, battery, and driver board

Connect the FPC cable to the XIAO ePaper Display Board

Metal side of the FPC cable should face upwards

Connect the battery to the JST connector

Red wire to +, black wire to -

(Optional) Assemble the enclosure

Use open-source designs from Printables or Thingiverse

Flash the TRMNL Firmware

Install the latest firmware on your device

Visit the TRMNL Web Flasher

usetrmnl.com/flasher

Connect your device via USB-C

Use a data-capable USB cable (not just charging)

Select firmware version 1.5.12 or newer

Follow the on-screen instructions to flash

Tip: If the web flasher doesn't work, you can build and flash from source using theTRMNL firmware repository

Connect to WiFi

Configure your device's network connection

Power on your device

The device will create a WiFi access point

Connect to the TRMNL WiFi network

Look for a network named "TRMNL-XXXX" on your phone or computer

Open the captive portal

Your browser should automatically open the configuration page

Select your home WiFi network and enter the password

The device will connect and restart

Configure BYOS Server URL

This is the most important step!

Reconnect to the TRMNL WiFi network

After WiFi setup, the device creates the access point again briefly

Open the captive portal settings

Look for "Server Settings" or "Base URL" option

Enter your BYOS server URL:

https://your-app.vercel.app

Make sure to include https:// and remove any trailing slashes

Save the settings

The device will restart and connect to your server

Verify Connection

Check that your device is registered

Wait for the device to boot up

This may take 30-60 seconds

Check your dashboard

Your device should appear in the device list

Note your device UUID

This is displayed on the device screen as a 6-digit Friendly ID

Create Your First Screen

Start displaying content on your device

Click on your device in the dashboard

Click "Create New Screen"

Choose a screen type (Clock, Weather, Quote, or Custom)

Configure and save

Your device will display the screen on its next refresh

Troubleshooting

Device not appearing in dashboard?

Verify the BYOS server URL is correct (no trailing slash)
Check that your device has internet connectivity
Look at the device screen for error messages
Try power cycling the device

Can't connect to TRMNL WiFi network?

Make sure the device is powered on and the battery is charged
The access point only stays active for a few minutes
Try resetting the device by holding the reset button

Screen not updating?

Check that at least one screen is marked as "active"
Verify the device is checking in (look at "Last Seen" time)
Check the logs page for error messages
Try manually refreshing the device (button press if available)

Need more help?

Visit the TRMNL documentation or check the firmware repository

Additional Resources

TRMNL BYOD/S Documentation Seeed Studio Hardware Guide TRMNL Firmware Repository TRMNL Web Flasher