TagTinker V2.1

Infrared ESL Research Toolkit for Flipper Zero
_{Protocol study • Signal analysis • Digital Art}

→ Launch the TagTinker Image Prep web app ←

Overview

TagTinker is a Flipper Zero app for exploring infrared electronic shelf-label (ESL) protocols. It allows you to transmit custom images and text to supported graphics tags. A companion web image preparer runs entirely in the browser and lets you drop, dither and download Flipper-ready BMPs without any install.

As the Flipper Zero team notes:

"FYI: this is pure infrared signal, same that you use in TV remotes. The whole security was relying on obscurity of protocol."

This tool is built for IoT security curiosity, learning about obscure protocols, and displaying digital art on e-ink hardware.

Warning

Hardware Warning: Many infrared ESL tags store their firmware, address, and display data in volatile RAM to save cost and energy. If you remove the battery or let it fully discharge, the tag will lose all programming and become unresponsive ("dead"). It usually cannot be recovered without the original base station.

Which tags work

TagTinker only transmits infrared, through the Flipper's IR LED. It works with infrared ESLs whose type code is in the app's profile table. The type code is digits 13 to 16 of the 17-character barcode, and the image preparer lists the graphics types.

TagTinker has no way to drive ESLs that are updated over radio, whatever their barcode or NFC tag says. For example:

• SES-imagotag's VUSION access points talk to their labels over a proprietary 2.4 GHz radio, and in 2023 SES-imagotag announced Bluetooth LE support for the platform.
• Hanshow documents labels such as the Stellar Pro-266 and Nebular Pro-346 as RF devices working at 2402 to 2480 MHz.

What + Scan NFC tells you

The scan only reads the tag's NFC data. It cannot sense whether the display listens for infrared or radio.

Message	What the Flipper found
Tag actions open	The NFC link carries an ID TagTinker decodes. Show Tag Info shows the model, or Model: Unknown when the type code is not in the profile table.
Likely radio tag	No decodable ID, and the NFC link points to nfc.imagotag.com, the host in the public VUSION label dump. The link alone does not prove the model.
Unrecognized tag	The chip was read, but its NFC data holds no ID TagTinker can decode. Everyday NFC cards land here too. For an infrared tag, try + Type Barcode.
Unreadable chip	An NFC-A chip answered, but no page could be read. The scan reads only NTAG/Ultralight chips; other chip types give this or "Unrecognized tag", depending on how they answer. If the tag moved during the read, take it away and present it again.
Target list full	All 16 target slots are in use. Delete a saved tag first.
Nothing happens	No NFC-A chip answered. The tag may have no NFC chip, or one of a type the scan does not look for.

Only test tags you own or are allowed to test.

Features

• TagTinker Flipper App: High-performance RLE streaming IR engine.

• TagTinker Image Prep (web): Single-file, dependency-free HTML page that lists every supported tag profile, runs a full image pipeline (tone, contrast, detail, sharpen, dither, photo-grade Oklab 3-colour quantisation) and exports a Flipper-ready BMP. Hosted at i12bp8.github.io/TagTinker (source: web-image-prep/).

• Drop-folder image flow: Drop a prepared BMP into apps_data/tagtinker/dropped/ on the Flipper SD card, then open Targeted Payloads → <tag> → Set Image and pick it. The Flipper rescales the 1-bit and two-plane BMPs that the image preparer exports, so one file can be sent to graphics tags of other sizes and to any page. Type 1626 (SmartTAG Color 2.6) targets only accept files up to 24 KB.

• NFC Tag Scan: Add a target by scanning the tag's NFC chip instead of typing its barcode. This works when the tag's NFC data carries an ID TagTinker can decode; otherwise use + Type Barcode.

• WiFi Plugins (optional): Plug a Flipper WiFi Dev Board (ESP32-S2) into the GPIO header to unlock live, network-rendered tag designs — crypto price cards, weather tiles, identicons, and more — auto-discovered by the FAP. New plugins live entirely on the cloud worker; the Flipper firmware never has to be re-flashed to add one. The dev board firmware talks to the worker named by CONFIG_TT_CLOUD_URL, so you can point it at your own deployment of cloud-plugins/ instead.

• Display text and custom images.

• Support for monochrome and accent-color (red/yellow) graphics tags.

Getting Started

1. Build the Flipper app from this repository and install it via ufbt. The first launch creates apps_data/tagtinker/dropped/ on your SD card.
2. Open i12bp8.github.io/TagTinker in any browser, pick your tag profile, drop an image, tweak, and download the BMP.
3. Copy the BMP into apps_data/tagtinker/dropped/ on the SD card (over qFlipper, USB MTP, or whatever you use).
4. On the Flipper open Targeted Payloads → <your tag> → Set Image, pick the BMP, choose a page, send.

Development

The repo holds three build products plus the static web tool. A root Makefile wraps every toolchain and works with the stock make on macOS (GNU Make 3.81) as well as GNU Make 4.x. Run make with no arguments to list all targets.

Prerequisites

• Python 3 — make setup creates .venv/ and installs ufbt into it for the Flipper app.
• Node.js 22+ (LTS) — for the Cloudflare worker in cloud-plugins/.
• ESP-IDF v5.2 (optional) — only needed to build or flash the WiFi devboard firmware in esp32-wifi-fw/. Install it at ~/esp/esp-idf or pass IDF_PATH=/path/to/esp-idf. ESP-IDF's export.sh expects a Python virtualenv matching the python3 on your PATH; if exactly one ~/.espressif/python_env/idf5.2_py*_env exists the Makefile points ESP-IDF at it automatically, otherwise pass IDF_PYTHON_ENV_PATH=... yourself.

Make targets

Target	What it does
make setup	One-time: create .venv/ with ufbt, download the Flipper SDK, npm ci the worker
make build-all	Build the FAP, the worker and the ESP32 firmware
make build-fap	Build the Flipper app → dist/tagtinker.fap
make launch	Build, install and run the FAP on a USB-connected Flipper (port auto-detected)
make build-worker	Type-check and bundle the worker → cloud-plugins/dist/index.js
make build-esp	Build the ESP32-S2 firmware → esp32-wifi-fw/build/tagtinker_wifi.bin
make flash-esp ESP_PORT=/dev/cu.usbserial-XXXX	Build and flash the devboard (omit ESP_PORT to auto-detect)
make serve-web	Serve the Image Prep tool at http://localhost:8000/
make lint	Advisory ufbt lint; it currently fails on deliberately column-aligned code and is not a CI gate
make clean	Remove build outputs only (keeps .venv/, node_modules/ and sdkconfig)

CI (build.yml) builds all three components — FAP, worker and ESP32 firmware — on every pull request and every push to main; the web tool deploys to GitHub Pages from main.

FAQ

Does this require a Flipper Zero?

This app does. The IR protocol itself is simple enough to drive from other cheap microcontroller hardware, such as an ESP32 and an IR LED, but this repository only contains the Flipper implementation. The Flipper Zero just happens to be my favorite security research tool, which is why I built the app for this platform.

Where is the .fap release?

The Flipper app is source-first. Build the .fap yourself from this repository with ufbt so it matches your firmware and local toolchain.

What if it crashes or behaves oddly?

If you are using a custom firmware branch, custom asset packs, or a heavily modified device setup, start by testing from a clean baseline firmware.

Credits & Background

This project is deeply indebted to the incredible public reverse-engineering work by furrtek. To understand the underlying protocol, signal structure, and history, please read his research:

• Furrtek’s ESL research: https://www.furrtek.org/?a=esl
• PrecIR reference implementation: https://github.com/furrtek/PrecIR

NFC tag decoding contributed by 7h30th3r0n3.

Disclaimer

Caution

STRICTLY PROHIBITED FOR ILLEGAL USE

TagTinker is an independent project intended strictly for educational research, security curiosity, and displaying digital art on hardware that you legally own.

Under no circumstances is this software allowed to be used for illegal activities. You are strictly prohibited from using TagTinker to alter retail displays, modify electronic shelf labels in stores, interfere with third-party infrastructure, or cause any form of vandalism or financial harm.

The creator of TagTinker assumes absolutely no liability for any misuse of this software. By using this software, you agree to take full responsibility for your actions and use it responsibly and legally.

License

Licensed under the GNU General Public License v3.0 (GPL-3.0). See the LICENSE file for details.