TRMNL for OpenFrame / O2 Joggler

A lightweight TRMNL display client for the OpenFrame / O2 Joggler — an Intel Atom-based 7" touchscreen appliance with an 800×480 display.

Polls the TRMNL cloud API and writes the dashboard image directly to the Linux framebuffer. No X11, no desktop environment — minimal footprint designed to fit on the device's 1GB internal flash.

Requirements

• Debian Trixie (or compatible) base OS
• A TRMNL account with a BYOD licence
• Your TRMNL API key

Installation

curl -sS https://raw.githubusercontent.com/birdslikewires/openframe-trmnl/main/install.sh | sudo bash

The installer will:

• Prompt for your TRMNL API key and write it to /etc/trmnl.conf
• Install dependencies (python3-pil, curl, jq) if not already present
• Install the client scripts to /opt/trmnl/
• Install and enable a systemd service that starts on boot

Updating

sudo bash /opt/trmnl/install.sh

Configuration

Edit /etc/trmnl.conf:

TRMNL_API_KEY="your_api_key_here"

Device model

When setting up your BYOD device in the TRMNL dashboard, select:

Inky Impression 7.3 - 800×480

This is the closest match currently available — same resolution, full colour PNG output. An OpenFrame-specific entry may be added in future.

Useful commands

journalctl -u trmnl -f      # live logs
systemctl restart trmnl     # restart the client
systemctl stop trmnl        # stop the client

How it works

The client polls https://usetrmnl.com/api/display with your API key, receives a PNG image URL and a refresh interval, downloads the image, and writes it directly to /dev/fb0 using a small Python script (display.py). It then sleeps for the instructed interval before polling again.

Acknowledgements

Built for the Joggler community. TRMNL is developed by usetrmnl.com.