The IoT Geiger Counter v3.1 is a DIY ESP32-based project that counts pulses from a Geiger–Müller tube and publishes one-minute counts over Wi-Fi using MQTT. Its example data path runs from an MQTT broker through Telegraf to InfluxDB, with Grafana for charts. It is a maker-oriented logging project—not a calibrated or certified radiation-safety instrument—and its author reported that the high-voltage supply was not stable enough.
What the IoT Geiger Counter v3.1 does
The v3.1 design uses an ESP32 to count events detected by a Geiger–Müller tube, manage the tube’s high-voltage supply, and send readings over Wi-Fi. The project author describes using it to “silently log[] radiation levels” in an attic. The practical aim is local monitoring and time-series logging, rather than a finished commercial product.
The project write-up was published on July 7, 2022. It links schematic and board-design material, but at publication the author said the source code was “not yet, coming later.” The available write-up therefore should not be treated as evidence of a maintained, turnkey software package or a complete tested kit. See the project write-up by g3gg0 and the Hackster.io hardware overview.
How readings move from the tube to Grafana
- Detect: The Geiger–Müller tube generates electrical pulses when it detects ionizing events.
- Count: The ESP32 counts pulses during a one-minute interval.
- Publish: The device sends the interval count over Wi-Fi via MQTT. The author also describes sending current environmental-sensor measurements and a voltage measurement.
- Store and visualize: In the author’s example, Telegraf ingests the data, InfluxDB stores it, and Grafana displays the time series.
The 2022 project write-up does not specify MQTT topic names, payload format, broker setup, quality-of-service level, or security settings. Those implementation details should not be assumed when recreating the project; they need to be established for the particular build and broker.
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- 【Nuclear radiation detector】GQ GMC-800 is the latest upgraded model of USA GQ Electronics Geiger Counters. Portable, personal & group use. Detect ionizing nuclear radiation Beta, Garma, X-ray. Quick, sensitive, precise & Easy-to-use. Simply power-on, reading instantly shows at screen. One press shortcut key transit among four function screens. Readable under the sun, suitable indoor & outdoor.
- 【Multifunctional】Traditional Geiger counter function to find the instantaneous radiation flux on a location/spot; Real-time & timeframe measuring function to display radiation data; Dosimeter function to obtain the real-time & accumulated radiation on human body; Radiation monitoring function to monitor radiation over time at a location.
- 【The measurement accuracy】is ensured via compliant design meets USA national standard (NIST & NRC). The calibration is done to further strengthen the accuracy and data quality. Easy access rechargeable & replaceable battery. Type C data transfer & charging cable. Light, thin & anti-drop. Handheld, stand on both sides, or lay down at the surface.
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- 【User Friendly Interface UI】Shorten learning curve, easy- to-navigate. The larger clear TFT color LCD display. Fast speed, immediate reading. Main screen simultaneously show reading in dosimeter units. User selectable color change scheme, customized light/dark mode for user preferences & visual comfort; Graphic, large font mode.
Tube options: SBM-20 and SBM-19
The documented build centers on an SBM-20-style tube. The author presents the physically larger SBM-19 as a more sensitive alternative, but also a more expensive one. The prices below are figures the author reported in 2022, not current quotes.
| Tube | Size and sensitivity | Author-reported price |
|---|---|---|
| SBM-20 | Common choice for this type of build; smaller and less sensitive than the SBM-19, according to the project author. | 20–25 € in the author’s 2022 write-up. |
| SBM-19 | Physically larger and more sensitive than the SBM-20, according to the project author. | 40 € in the author’s 2022 write-up. |
These are qualitative comparisons from the project author, not independent performance measurements. Confirm present-day availability, suitability, and pricing before choosing a tube.
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- Dosimeter mode, CPM count mode, Graph mode
Other documented hardware and design caveats
The ESP32 controls a boost converter that supplies the voltage needed by the tube. Hackster’s approximately 2022 overview describes the design as generating 400 V. That figure is a design description, not proof that a particular replica will produce a stable or correctly regulated output. The project author explicitly said the high voltage was “not very stable” and that its control implementation needed more work.
Other components described in the project sources include a CCS811 volatile-organic-compound sensor, a BME280 temperature and humidity sensor, WS2812 RGB LEDs, and an optional 5.83-inch e-paper display. The author noted that temperature readings needed improvement and that the e-paper visualization was still rough. An inductor for the boost converter was among the sourcing challenges discussed. These details describe the published design; they do not establish that every component is required for a minimal MQTT counter.
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- 【Multifunctional】Traditional Geiger counter function to find the instantaneous radiation flux on a location/spot; Real-time & timeframe measuring function to display radiation data; Dosimeter function to obtain the real-time & accumulated radiation on human body; Radiation monitoring function to monitor radiation over time at a location.
- 【The measurement accuracy】is ensured via compliant design meets USA national standard (NIST & NRC). The calibration is done to further strengthen the accuracy and data quality. Easy access rechargeable & replaceable battery. Type C data transfer & charging cable. Light, thin & anti-drop. Handheld, stand on both sides, or lay down at the surface.
- 【Five types of radiation alarms】Visual LED, Audio, Vibration, Voice. Four alarm types provide everyone including vision-impaired & hearing-impaired users. The alarm level threshold can be set by users. Exclusive Advanced Features are integrated in. Built-in Clock, Memory for data storage up to 10 years. Free data processing software & firmware updates & open protocol & online data storage & history data preview. Navigate menu & submenu to explore.
- 【User Friendly Interface UI】Shorten learning curve, easy- to-navigate. The larger clear TFT color LCD display. Fast speed, immediate reading. Main screen simultaneously show reading in dosimeter units. User selectable color change scheme, customized light/dark mode for user preferences & visual comfort; Graphic, large font mode.
What the readings can—and cannot—tell you
The documented output is a count accumulated over one minute. The reviewed project sources do not provide a calibration against a reference instrument, a validated conversion from counts to dose rate for this specific tube and circuit, measurement uncertainty, or evidence of regulatory compliance. They also do not validate the device as an exposure-warning instrument.
Use the project as an experimental counter and logging system, and describe its output as counts or counter readings unless the specific build has been properly calibrated. The reported high-voltage instability is an additional reason not to rely on it for safety decisions. For exposure assessment or radiation-safety decisions, use an appropriately validated instrument and follow qualified guidance.
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- Nuclear Radiation Detector: The AEGTEST Radar-5633 Radiation Detector utilizes cutting-edge semiconductor sensors to rapidly and accurately detect ionizing radiation, including Beta, Gamma and X-rays. It features an energy response range of 33 keV to 3 MeV with an accuracy of -17% to +20% (for ¹³⁷Cs γ). The cumulative dose range spans 0.1 μSv to 9999 mSv, making it ideal for both professional use and everyday radiation protection
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- History Data Logging & Powerful Battery: With a timed measurement function, the geiger counter automatically stores historical data after each session, allowing you to efficiently track and review radiation levels over time. Plus, the convenient Type-C charging supports an impressive battery life of up to 18 days (particle sound turned off) on a single charge
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What to check before building
- Review the author’s schematic and board-design references and verify that the files you intend to use are currently available and complete.
- Confirm the tube, boost-converter components, and inductor are compatible with the intended circuit and their electrical ratings.
- Plan and verify the high-voltage section carefully; the project author identified stability and controller work as unresolved issues.
- Choose whether you need the additional environmental sensors, LEDs, or optional display; these add hardware and are not evidence of improved radiation-measurement accuracy.
- Define your own MQTT topics, payload, broker configuration, and security because the project write-up does not document them.
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