TRMNL client for Nook Simple Touch

A TRMNL client for the Nook Simple Touch (BNRV300) and Nook Simple Touch with Glowlight (BNRV350). These devices usually go for around $30 on eBay and have an 800x600 e-ink display.

Configuration screen

Fullscreen view

Menu dialog

Questions or feedback? Please open an issue.

Table of Contents

• Prerequisites
• Install
  • Easy Setup
  • Manual Setup
• Device Settings
• Features
• Deep Sleep Mode
• Aggressive Sleep
• Frames and Cases
• Gift Mode
• Roadmap
• Other Nook Models
• Development
• Disclaimer

Prerequisites

• Root the device using the Phoenix Project. I used "phase 4" (the minimal rooted install for customization). The phases were confusing because you do not need phase 1/2/3 (each is a separate backup).
• Buy a TRMNL BYOD license and grab your SSID + API key from Developer Settings after login (or use your own server).

Install

Easy Setup (recommended)

I built a web tool that handles the whole setup over USB — installs the app, configures settings, and gets you on WiFi, all from the browser. No ADB needed.

Requires Chrome or Edge (WebUSB). Your NOOK must be rooted first via the Phoenix Project phase 4 before it'll show up.

The wizard walks you through five steps:

1. Connect — Plug in your NOOK via USB, then click "Connect Device" to open the browser's USB picker. If prompted on the NOOK screen, tap Allow to authorize the connection.
2. Setup — Reads your device model, verifies the TRMNL app is installed (installing or updating it if needed), and applies any missing system settings automatically.
3. TRMNL — Sign up at trmnl.com, then enter the MAC address and Device API Key from your device's Developer Perks page. Self-hosted (BYOS) and gift mode are available under advanced options.
4. Network — If your NOOK is already on a network, this step confirms the connection and moves on. Otherwise, it scans for nearby networks and writes the credentials directly to the device.
5. Done — Your NOOK is ready. Unplug the USB cable and manage plugins and settings at trmnl.com.

The web tool configures all required device settings automatically, including those listed in Device Settings below.

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Manual Setup

1. Download the APK from GitHub Releases.
2. Connect the Nook Simple Touch over USB and copy the APK over.
3. Open the included ES File Explorer app.
4. In ES File Explorer: Favorites -> "/" -> "media" -> "My Files".
5. Tap the APK and install.
6. Connect your device to WiFi.
7. Open the app and configure the device info.

After installing manually, you'll also need to configure Device Settings.

Device Settings

In the TRMNL Device settings, set the device type to "Nook Simple Touch" as the TRMNL team was nice enough to add support for this device!

The web tool applies all of the settings below automatically. If you installed manually, configure each one by hand:

Where	Setting	Value	Purpose
Nook Settings → Display → Screensaver	Screensaver	TRMNL / 2 min timeout	Points the screensaver at the TRMNL image and ensures it activates for deep sleep
Apps → Nook Touch Mod	Hide screensaver banner	Enabled	Hides the text overlay on the screensaver
Apps → Nook Touch Mod	Disable drag to unlock	Enabled	Skips the drag-to-unlock gesture on screensaver wake
Apps → Nook Touch Mod (optional)	Home button (short press)	Launches TRMNL app	Remaps the physical Home button to open TRMNL directly
Apps → Nook Touch Mod (optional)	Home button (long press)	Opens App Drawer	Remaps long-press Home to the app drawer
TRMNL app → Settings → General	Sleep between updates	Enabled	Enables deep sleep between refresh cycles
TRMNL app → Settings → General	Aggressive sleep	Enabled	Sleeps immediately after each refresh rather than waiting for timeout

Note: Nook Touch Mod settings require Nook Mod Manager (NMM) to be installed (included in Phoenix Project phase 4). The Home button remapping rows are optional — the app works without them.

Features

• On-device config UI for device ID, API key, and API URL (BYOS)
• Fetches your screen and shows it fullscreen, bypassing the lock screen until you exit
• Respects playlist intervals to advance to the next screen
• TLS v1.2 via BouncyCastle (not included in Android 2.1)
• BYOD support for TRMNL and custom server URLs
• Reports battery voltage and Wi-Fi signal strength
• Deep sleep mode for 30+ day battery life
• Aggressive sleep for maximum battery savings (benchmarking TBD)
• Gift Mode for pre-configuring devices as gifts

Deep Sleep Mode

Without deep sleep, expect ~60 hours of battery life. With deep sleep and a 30-minute refresh rate, battery lasts 30+ days. The app writes each image to the Nook's screensaver, turns off WiFi, and sets an RTC alarm to wake for the next refresh.

To enable:

1. In the app: Enable "Sleep between updates"
2. In Nook Settings → Display → Screensaver: Set to "TRMNL" with 2-minute timeout
3. In Apps → Nook Touch Mod: Enable "Hide Screensaver Banner"

Aggressive Sleep

Aggressive sleep is an optional mode on top of deep sleep that puts the device to sleep immediately after each scheduled image refresh, rather than waiting for the screensaver timeout. This can further improve battery life, though benchmarking is still in progress — exact savings are TBD.

To enable:

1. First enable "Sleep between updates" (see Deep Sleep Mode)
2. In the app: Settings → General → Enable "Aggressive sleep"

You can also trigger a manual sleep at any time from Settings → System → "Sleep".

Frames and Cases

The Nook Simple Touch often develops sticky residue on its rubberized surfaces as it ages. iFixit has great teardown and repair guides if you need to clean or refurbish your device.

For a custom frame, I recommend this 3D-printed case on Thingiverse. It requires:

• M3x4 flush screws
• M3x5x4 threaded inserts (soldering iron required to install)
• The original screws and inserts from the Nook Simple Touch

Gift Mode

Gift Mode displays setup instructions instead of fetching content—perfect for giving a pre-configured device as a gift.

To set up:

1. Buy a BYOD license for the recipient
2. Get the friendly device code from trmnl.com/claim-a-device
3. In the app: Settings → Enable "Gift mode" → "Configure Gift Mode"
4. Enter your name, recipient's name, and the device code

Roadmap

See GitHub Issues for the roadmap and to submit feature requests.

Development

See the CI workflow for build details (build-apk.yml), and the tools/ adb scripts for build/install workflows. A development guide is coming (#8). In the meantime, the project can be built with surprisingly minimal, self-contained dependencies.

Other Nook Models

This repository targets legacy Nook devices running Android 2.1 (API 7), which requires different tooling and approaches than modern Android. For newer Nook devices like the Nook Glowlight 4, see trmnl-nook.

If you have another Nook model from this era that you'd like to test, please open an issue!

Disclaimer

AI was used to help code this repo. I have a software development background, but did not want to relearn old Java and the Android 2.1 ecosystem. Despite best-effort scanning and review, the device and/or this software may contain vulnerabilities. Use at your own risk, and if you want to be safer, run it on a guest network.