With protective case

Flipper Zero Geiger Counter Module — Radiation Detector Add-On (Beta & Gamma)

What Is This?

This is a compact, plug-in Geiger counter module designed specifically for the Flipper Zero. It transforms your Flipper into a portable radiation detector / dosimeter capable of measuring beta (β) and gamma (γ) radiation using the built-in J305 Geiger tube. The module interfaces with the Geiger counter app by nmrr for real-time readings and also supports the Atomic Dice Roller for generating true random numbers from environmental radiation signals.

Why I Made It

As an electronics enthusiast and a maker, I wanted a slim, hackable, and fully integrated Geiger counter for the Flipper Zero. Typical radiation detectors are bulky or closed-source; I wanted something open, DIY-friendly, and immediately usable in the field. Also, combining radiation sensing with hardware-based randomness (via Geiger pulses) allows fun and novel projects — hence support for the Atomic Dice Roller. I built this module to be both practical and playful.

Key Selling Points & Features

Flipper-Native Accessory: a clean, plug-in module for Flipper Zero without bulky housing — ideal for field portability.

J305 Geiger Tube: dependable detection of β and γ radiation (counts per minute). Real-Time Monitoring: works with the Geiger counter app (credit nmrr), giving live counts, dose estimates, and logging.

True RNG via Radiation: integrated support for Atomic Dice Roller app — use environmental radiation to generate genuine randomness for games or experiments.

DIY & Modder Friendly: exposed pads, clear labeling, optional connector footprints for custom installs or expansions.

Lightweight & Portable: ideal for everyday carry, field checks, or integrated projects.

Open Ecosystem: compatible with Unleashed firmware and other community forks — suitable for makers who want full control.

Practical Radiological Awareness: provides quick scans and alerts in unexpected environments, giving you immediate feedback on radiation levels.

Technical Overview & Typical Use

Detection & Measurement

Uses a J305 Geiger-Müller tube configured to detect β and γ particles.

Outputs pulse counts per minute (CPM).

The Geiger counter app translates CPM to approximate dose rate (e.g. µSv/h) using defined calibration parameters.

Supports logging over time for radiation exposure trends.

Integration with Flipper Zero

Module plugs into Flipper’s accessory interface (or designated connector).

Data is fetched via I/O interface and visualized in the Geiger counter app.

For randomness, radiation pulses act as entropy events passed to the Atomic Dice Roller logic layer.

Power & Connections

Powered from Flipper Zero’s internal 3.3 V (or compatible supply rail).

Minimal current draw during idle; pulses cause transient current.

PCB layout includes optional header pads for custom wiring or external battery feed.

Clear marking of +, GND, signal lines.

Operation Modes

Radiation monitoring mode — read counts/µSv, log, thresholds.

RNG / gaming mode — convert pulses into true random bits via dice rolling logic.

Calibration / firmware mode — advanced users can flash calibration constants or alternative firmwares.

Installation & Usage (Based on Typical Manual Workflow)

Attach the module to your Flipper Zero via the designated port or mounting area.

Launch the Geiger counter app on Flipper; configure whether pulses measure β, γ or both.

If desired, use Atomic Dice Roller app to produce randomness from pulses.

Cap or shield the unit when not in use to reduce background noise.

For safe measurements, avoid pointing it directly at known radioactive sources unless you know what you are doing.

If you upgrade firmware (e.g. Unleashed or custom builds), ensure compatibility with the module’s pulse input logic and pinouts.

Safety & Limitations

This is a hobbyist-grade detector, not a certified professional instrument. Use it for awareness and general guidance only.

It is not a substitute for safety-grade radiation survey meters in critical environments.

Background radiation (cosmic rays, soil potassium, building materials) may produce counts; calibration is approximate.

Do not use in extreme temperature, high humidity or dangerous contamination zones.

Always verify radiation readings with certified instruments or professionals when making safety decisions.

If you’re a DIY electronics enthusiast, Flipper Zero user, or a maker who loves combining utility and fun, this Flipper Zero Geiger Counter module is built for you. It’s compact, open, hackable, and designed to provide both radiation sensing and true random generation in one package. Whether you want to perform environmental radiation scans, power random games, or integrate into custom scripts, this module is a uniquely powerful tool in your maker toolkit.