The FlipperHeimer is a compact Geiger counter add-on module designed to work with the Flipper Zero. It allows users to monitor beta and gamma radiation levels using the Flipper’s display and power source, making it a portable device to detect radiation.
Built around a J305 Geiger–Müller tube, the FlippenHeimer provides real-time data logging, visual feedback via graphs. Other than that, it features “atomic dice roller” functionality that uses the random nature of radioactive decay to generate unpredictable outcomes. Key components of this device include 555 timers, LM358 op-amps, 2N3904 and MPSA42 transistors, inductors, and high-voltage capacitors. These features make this device useful for applications such as environmental awareness, hobbyist radiation monitoring, and generating random values.
FlippenHeimer Specifications:
- Main interface – Connects to Flipper Zero via GPIO/UART (plug-and-play with GPIO header)
- Detection device – J305 Geiger-Müller glass tube, suitable for gamma and beta radiation
- Radiation detection:
- Detects beta and gamma radiation
- Clicks/counts via onboard piezo buzzer and LED
- Display – Uses Flipper Zero display for live CPM/µSv readout (via community app)
- Feedback – Audible clicker and visual LED indicator for real-time detection
- Power
- Tube Operating voltage – 400V DC generated via onboard boost converter
- Main power – Powered by Flipper Zero (no external power required)
- Dimensions – 117 x 28.9 x 17.7 mm (with enclosure)
- Enclosure – Optional 3D-printable case available
This Geiger counter module for Flipper Zero works with custom firmware forks like RogueMaster and Unleashed, which provide real-time readouts of radiation levels in counts per minute (CPM) and microsieverts per hour (µSv/h), which are displayed clearly on the device’s LCD screen. Users can monitor radiation levels visually or audibly through clicks and LED indicators. The project is completely open-sourced, and all the details, including schematic, app compatibility details, calibration steps, and required electronic components, can be found on FlipperHeimer’s GitHub repository.
Previously, we have written about various addon boards for the Flipper Zero, including the Flipper Blackhat open-source dual-band Wi-Fi card running Linux and designed for penetration testing, cybersecurity research, and wireless network analysis, Sacred Labs’ FlipMods Combo is a 3-in-1 expansion module which combines an ESP32, CC1101 Sub-GHz wireless microcontroller, and a GPS module that comes with preinstalled Marauder firmware. We also wrote about Geiger counter solutions for smartphones.
The FlippenHeimer module comes in three versions – the Ultimate (fully assembled with a 3D-printed case), the El Handy KIT (DIY kit excluding 3D parts), and Poverty (only the PCB with SMDs pre-soldered). The kit is priced at $37.34 on the Tindie Store. While searching for more details about the product, I found another DIY Geiger counter kit on AliExpress, which costs around $25 and can work with the flipper module, ESP32 boards, etc…
Debashis Das is a technical content writer and embedded engineer with over five years of experience in the industry. With expertise in Embedded C, PCB Design, and SEO optimization, he effectively blends difficult technical topics with clear communication
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This project shares the same design flaws with many other Geiger counters (including the kits from China):
Use a better design or make your own. It’s actually pretty easy to use a premade (powerful) high voltage converter and add voltage measurement and regulation.