Features:

• Breadboard view: realistic image of the module.
• Schematic view: clear and standard symbol for easy circuit design.
• PCB view: accurately placed copper pads with a correct pitch of 2.54 mm (0.1″) and a silk screen mask.
• Complete metadata: correct family, manufacturer, and pin designations.

Installation:

• Download the latest version of the .fzpz file.
• Open Fritzing.
• Go to the File > Open menu and select the downloaded .fzpz file.
• The GGreg20_V3 module will appear in your My Parts basket.

We at IoT-devices plan to use this part ourselves to create materials for our publications. We hope that your DIY radiation measurement projects will become even better. The part file is available on GitHub and on the Fritzing forum, in the branch dedicated to the development of new components.

As a next step, we plan to submit the part we have developed for consideration for inclusion in the official Fritzing component database. Follow our posts.

Links:
GGreg20_V3 module description on the website;
GGreg20_V3 component on GitHub;
GGreg20_V3 on Etsy;
GGreg20_V3 companion app on Google Play.

About Norton Safe Web:

https://safeweb.norton.com/help/about

Related links:

• Publications: https://iot-devices.com.ua/en/blog/
• Online store (for international orders and orders from Ukraine): https://iot-devices.com.ua/en/shop-2/
• Profile on Trustpilot: https://go.iot-devices.com.ua/trustpilot
• Store and reviews on Etsy: https://iotdevicesllc.etsy.com

Although our contribution to ESPHome is quite modest, it is nice to know that we are also part of a community of wonderful people and companies who created ESPHome and continue to make it better every day.

You can view the list of contributors here. Or in the Internet Archive via Wayback Machine.

Related Links:

ESPHome Devices

GitHub

For makers who want to purchase the GGreg20_V3 Geiger counter module without a tube (because they already own a compatible tube or plan to source one elsewhere), this small technical note details the dimensions of the tube mounting on our module’s PCB.

As you can imagine, having the option to buy just the module can be very convenient for some. We have always provided this option (on our website, Etsy, and previously on Tindie) — allowing you to select and order only the components you need right now. Over time, we received feedback, gained experience, and discussed this matter with our customers.

Note: The GGreg20_V3 was originally designed for the SBM20 tube, but its Soviet-era stock quickly ran out, so we specifically chose the even better J305 tube as a replacement. This means the standard SBM20 will also fit the module, as it was the tube we originally designed it for.

It turns out that the Chinese market offers J305 tubes with varying dimensions. This is why we want to explain exactly which J305 tube (or similar) will fit the GGreg20_V3.

We provide data for the J305 tube that we currently supply with the GGreg20_V3. We use the data provided to us by our J305 tube supplier from China.

Further on, we include a technical drawing with dimensions and a few photos to clearly illustrate the setup.

We also provide a photo of several J305 tubes from the latest batch, which clearly shows that while J305 tubes have minor size variations, they can be considered identical for our purpose. In several years of working with the J305, we have only encountered two initially defective tubes, as well as one tube that significantly differed in size from the rest of the batch and from the dimensions specified in the datasheet.

We hope this publication will help you understand which tube to choose so that it fits the module, particularly in terms of length.

Good luck!
IoT-devices team

Seamless Integration of Radiation Monitoring

The ggreg20_v3 component is designed for smart home enthusiasts and developers who seek to add ionizing radiation monitoring capabilities to their devices.

It provides a comprehensive set of data points essential for complete environmental control, including:

• Radiation Power (μSv/h)
• Equivalent Absorbed Dose (μSv/h)
• Total Accumulated Dose (μSv)
• Counts Per Minute (CPM) over the defined measurement period
• Instantaneous pulse count value
• System Status (alerts for danger, normal levels, or sensor errors)

This component autonomously handles all complex calculations, including dead time correction for the tube, delivering all necessary data for seamless automation within Home Assistant.

Key Advantage: Cross-Controller Compatibility

The core value of the component developed by IoT-devices LLC lies in its versatility. The ggreg20_v3 component is cross-controller compatible, supporting any microcontroller that runs ESPHome (including ESP32, ESP8266, Raspberry Pi Pico W, and others).

This eliminates the need to write individual code for different hardware platforms, allowing users to rapidly integrate radiation monitoring regardless of the specific controller used for their projects.

“We built ggreg20_v3 with the ESPHome community in mind. Our goal is to make environmental monitoring as accessible and reliable as possible by providing a single, flexible solution that works across all supported controllers,” commented IoT-devices LLC representatives.

How to Get Started

The ggreg20_v3 component is available as an external Git component.

To install: Add our repository to your ESPHome configuration and follow our detailed documentation.

• GitHub Repository: [https://github.com/iotdevicesdev/esphome_external_components]
• Documentation: Review the README.md file for full installation and configuration instructions.

IoT-devices LLC welcomes the community to test, provide feedback, and contribute to the component’s development.

The first product, which is already available for order, is a plastic case for the popular Raspberry Pi Pico W microcontroller with straight pin headers.

Just like IoT-devices’ own products, the items under the IoT Case Lab brand are supplied by the company under the same terms and policies, with global shipping available.

Customers from over 40 countries can already place orders on the website’s store. There are also plans to list the ICL-branded products in the IoT-devices LLC store on the Etsy marketplace.

A Product That Solves Problems

ICL products address common issues that DIY developers constantly face. The most popular components are typically connected using Dupont cables, which have a significant flaw: they often have a loose fit, leading to unstable connections and potential project failures.

The engineers at IoT Case Lab took this problem into account and designed a case that not only protects the microcontroller from external damage and short circuits but also securely fastens the Dupont connectors. This ensures a stable connection and makes the device easy to use.

Key Features of the case line:

• Specialized Design: The cases are specifically designed for certain microcontroller models, in this case, the Raspberry Pi Pico W with straight pin headers.
• Secure Connection: Dupont cable connectors are firmly secured by a panel, preventing them from accidentally disconnecting.
• Full Functionality: All pin headers, the BOOTSEL button, the Debug port, and the micro-USB port remain fully accessible.
• Protection and Cooling: The case protects the controller board from mechanical damage, while ventilation holes provide passive cooling.
• Universal Mounting: Thanks to special universal connectors, ICL cases can be joined with each other.

Details and Links

This case can be ordered on the IoT-devices website via the following link:
https://iot-devices.com.ua/en/product/raspberry-pi-pico-w-icl-rpipw-st-v1-plastic-case-straight/

For those who want to get to know the product better, all information is available on GitHub:
https://github.com/IoTCaseLab/ICL_RPIPW_ST_V1-case-for-Raspberry-Pi-Pico-W-with-straight-pin-headers

3D model of the case’s outer contours: https://github.com/IoTCaseLab/ICL_RPIPW_ST_V1-case-for-Raspberry-Pi-Pico-W-with-straight-pin-headers/blob/main/res/RPi-Pico-W-2022-model_straight_mcu2-type2_solidDemoBrick.stl

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

Screenshot of the profile on the Registry Operator’s website:

Screenshot of the excerpt in the national standings:

Screenshot of the excerpt in the regional standings:

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

As new users of the GGreg20_V3 module may have noticed, the board now comes in black. The black PCB is likely the tenth generation of the GGreg20_V3 module. This version features an improved circuit for smoother high-voltage regulation and a voltage limit of approximately 600 volts.

The module also comes with two stickers. The first is a Q.C. (Quality Control) sticker on the back of the board. The second is a VOID (warranty) sticker placed on the module’s high-voltage adjustment potentiometer.

Since implementing these changes—over six months ago—we’ve had the opportunity to gather feedback from our customers. One of the most common questions directed at our support team has been about the VOID sticker. Naturally, people are curious (and sometimes even genuinely frustrated) about why we’ve restricted high-voltage adjustments and what this sticker actually means in practice.

Let’s go over everything step by step.

Over the past year (2023–2024), we grew increasingly concerned about the statistics on sudden module failures. Diagnostics consistently pointed to excessively high voltage as the likely cause. Over time, this inevitably damages module components and can even lead to the failure of the Geiger tube.

That’s why, starting around September–October 2024, we introduced several improvements to our internal quality control procedures. The Q.C. sticker is now applied at the final stage of product testing.

Additionally, we decided to further restrict access to the potentiometer’s settings.

Since the module requires precise tuning and this part of the circuit is analog, the potentiometer’s setting can be easily disrupted—whether during use, due to vibrations in transport, or for other reasons. We hope that the VOID sticker now serves as an additional safeguard, keeping the potentiometer fixed in the position set by our specialists.

This sticker also acts as a warning for both beginners and experienced users: if you’re not sure, don’t touch it.
Our goal is to ensure that anyone considering adjusting the potentiometer first makes sure they know what they’re doing, understands the correct procedure, and has the necessary tools.

Now, what about cases where adjusting the high voltage is actually necessary? As far as we know, there is only one such scenario: when replacing the Geiger tube with one that requires significantly different operating voltage.
For example, if you’re swapping a J305 tube for an SBM20 (or vice versa), there’s no need to adjust the module, since their recommended operating voltages are almost the same—380V for J305 and 400V for SBM20. However, if you’re replacing a J305 with an LND712, then an adjustment is necessary to change the operating voltage from 400V to 500V.

Some customers have asked: What should I do if I absolutely need to adjust the potentiometer to a different voltage?

Warning!

The module operates at voltages that can be hazardous to health and life. Do not violate safety regulations or electrical installation standards. If you’re unsure, it’s best to consult a qualified specialist with the proper experience and certifications.

Our Recommendations

1. Review the technical note on initial self-diagnosis of voltages on the GGreg20_V3 module.
2. Use the knowledge gained (see point 1) to correctly measure the voltages on the module without adjusting the potentiometer. Ensure that you are using the appropriate measuring tools and following the procedures outlined in the note.
3. Contact (via email) our support team to inform us that you plan to adjust the settings. If needed, consult with our specialists for guidance.
4. Adjust the potentiometer to the required voltage by removing the VOID sticker.

Conclusions:

• Since implementing Q.C. and VOID stickers as part of our improved procedures, we have not received a single report of GGreg20_V3 module failure.
• If you need to replace an SBM20 tube with a J305, there is no need to adjust the potentiometer. The operating voltage ranges of these Geiger tubes overlap, so you can simply swap the tube.
• Every module shipped with a Q.C. sticker has been properly calibrated and extensively tested. Our test bench records measurement statistics to verify the performance and stability of both the module and the tube over an extended testing period—typically about an hour. Only after passing these tests does our specialist approve the module for shipment.
• The extended final testing phase also allows for selective thermal control of module components, ensuring long-term reliability.
• The VOID warranty sticker on the potentiometer does not restrict you as a user. It simply serves as a warning that adjusting the potentiometer without proper knowledge and tools is dangerous. By breaking the VOID seal, the user knowingly accepts the associated risks.
• If you follow the documentation and handle the module correctly, you won’t need warranty service, repairs, or replacement for your GGreg20_V3.
• Simply leave the VOID sticker intact and avoid adjusting the settings unless absolutely necessary.