Our Idea

Over the past few years, we’ve encountered situations where a Geiger counter needed to be used simply and quickly, without specialized knowledge or experience, without connecting additional devices, and without complex communication. Of course, you could just count pulses and time them with a stopwatch. But we thought, why not create a convenient app for this? And we did.

Benefits of Using GGreg20_V3 with This App

• Affordable Solution: No need for a controller like Arduino, ESP8266, ESP32, or Raspberry Pi.
• Ease of Use: No programming skills required.
• Wireless: No need to solder or connect cables.
• Quick Start: No need to search for or pair a new device.
• Broadcasting: If needed, one Geiger counter can be used simultaneously by many users.

Who This App Is For

While this app isn’t precise and, paired with GGreg20_V3, isn’t a finished device, users who can’t or don’t want to program can immediately use the GGreg20_V3 module simply by powering it and installing this app.

But remember, this is only an educational, demonstration, and testing app for beginners. Please choose appropriate tools for appropriate tasks.

This app is also convenient for quickly testing the module’s functionality, for example, when picking it up at the post office.

For Accurate Measurements

If you’re looking for accurate and reliable measurements using the GGreg20_V3 module, we recommend checking out our other companion app for GGreg20_V3, which is about to appear on Google Play. That app uses a controller with Bluetooth as the data transfer channel between the module and the smartphone.

Please note: the BLE app requires significantly more work on the DIY project – at least knowledge of ESPHome, BLE Server, and controllers like ESP32 or Raspberry Pi Pico W, etc.

How It Works

GGreg20_V3 users only need the module powered (according to documentation) and this smartphone app. Wireless data transfer from the GGreg20_V3 module to your smartphone occurs via sound signals from its built-in buzzer. The app filters sounds captured by the smartphone’s microphone, recognizing only those that match the signals from the GGreg20_V3 buzzer.

Known Limitations

Using the wireless audio channel can lead to false readings or inaccuracies in noisy environments.

Specifically:

• Although the GGreg20_V3 Geiger counter can register all pulses that tubes like J305, SBM20, or LND712 are capable of in high-radiation conditions, this app has a significant limitation. To differentiate pulses, an artificial 70-millisecond delay between the pulses the app perceives had to be implemented. This means the app can correctly process radiation levels only up to 850 CPM (or 3 uSv/hour). This is entirely sufficient for normal household conditions but will be insufficient in the event of a nuclear disaster.
• While the app effectively filters events only of a specific frequency, there’s a problem of signal clutter, for instance, from a nearby conversation. In such cases, the signals overlap, and the app ignores relevant pulses.
• We’re also aware of an echo problem with relevant signals. This occurs in enclosed spaces. You can see this effect in the video in the app description on Google Play, where the buzzer pulses once, but the app sometimes counts them twice, likely due to echo. (For shooting this video, we use a lightbox where the echo occurs.)

Important Note

This app, like the GGreg20_V3 module, is not a precise measuring device. It’s intended for personal use, hobbies, learning, and creative experiments, not as a finished product. It’s created for DIY electronics enthusiasts.

Keywords

Geiger counter, GGreg20_V3, Ionizing Radiation, Companion Application, Conversion Factor, Geiger Muller Tube, DIY, IoT, Radiation Measurement, Embedded Electronics, Electronics

This news post covers the first part of the project: the ESP32 BLE Server. We’ve developed a YAML example for ESPHome firmware. Since we already have several ESPHome examples out there, we figured it was a no-brainer to stick with this awesome, popular, and relatively straightforward technology.

The BLE Server you create using our example will be able to run completely standalone or integrate seamlessly with your Home Assistant (HA) server. So, if you’re an HA user, you’ll have the flexibility to choose how you want to deploy our example. If you don’t use HA, no worries! You can still use your GGreg20_V3 Geiger counter with the ESP32 BLE solution in a fully autonomous setup, free from any other additional tech.

It’s also worth noting that while our example is geared towards the classic ESP32 microcontroller, with just a few minor tweaks to the YAML configuration, you can use this example with any other ESPHome-supported controller that has an onboard BLE radio module.

You can find the full description of this project section, along with the YAML configuration file for creating the firmware, on our GitHub via the link here:

https://github.com/iotdevicesdev/GGreg20_V3-BLE_Server-ESP32-ESPHome

In Part 2, we plan to release an example of a ready-to-go client application for Android OS. We’ll also dive into how we developed it and the features we’ve packed in. The process is currently a bit held up by the Google Play Store publishing procedure.

Additionally, we’re planning to release the source MIT AI2 “code” for the app, making it freely available.

Kyiv. Ukraine. 2025

ORCID: 0009-0002-6482-9419