Radioactivity has always been a fascinating phenomenon for anyone interested in physics, and as a result we’ve featured many radioactivity-related projects on these pages over the years. More recently however, fears of nuclear disaster have prompted many hackers to look into environmental radiation monitoring. [Malte] was one of those looking to upgrade the radiation monitor on his weather station, but found the options for wireless geiger counters a bit limited.

So he decided to build himself his own Wifi and LoRa compatible environmental radiation monitor. Like most such projects it’s based on the ubiquitous Soviet-made SBM-20 GM tube, although the design also supports the Chinese J305βγ model. In either case, the tube’s operating voltage is generated by a discrete-transistor based oscillator which boosts the board’s 5 V supply to around 400 V with the help of an inductor and a voltage multiplier.

The tube’s output signal is converted into clean digital pulses to be counted by either an ESP32 or a Moteino R6, depending on the choice of wireless protocol. The ESP can make its data available through a web interface using its WiFi interface, while the Moteino can communicate through LoRa and sends out its data using MQTT. The resulting data is a counts-per-minute value which can be converted into an equivalent dose in Sievert using a simple conversion formula.

All design files are available on [Malte]’s website, including a PCB layout that neatly fits inside standard waterproof enclosures. Getting more radiation monitors out in the field can only be a good thing, as we found out when we tried to detect a radiation accident using community-sourced data back in 2019. Don’t like WiFi or LoRa? There’s plenty of other ways to connect your GM tubes to the internet.

please 2 device and connect to readio@ctive at home

I’d like to see or discuss a wide-spectrum sonar array with up to 300m and a magnometer? Think it’s possible with the LoaWAN specs?

Every Russian geiger tube you buy is funding Russian war cimes in countries of Eastern Europe.

Unless you buy New Old Stock from a Ukrainian seller in Kyiv I suppose?

For example you may see at GGreg20_V3, built by IoT-devices, Kyiv based company. Using devices like this you mostly support ukrainian manufacturer and their people, then at last old soviet GM tubes ;-)

For every one you don’t buy, I am going to buy two.

Hmmm, I wonder if LaCrosse Scientific would consider a Geiger counter option for their home wx stations… They could even have an indoor unit for radon.

Cool! This is an idea that lies on the surface. All radio amateurs, for a reason I do not understand, make complex and beautiful weather stations that include only the BME280, which allows you to measure temperature, atmospheric pressure and relative humidity. At the same time, forget about such environmental parameters as background radiation or ultraviolet level. I have already given as an example the GGreg20_V3 module, which is excellent for both stationary and pocket-sized DIY / IoT devices for measuring radiation indoor and outdoor and btw is supported by majority of MCUs and Dev. environments.

If you want early-warning detection of something like a reactor accident, you’d probably want to detect alpha emitters instead, and this would require a mica window tube. The metal-wall tube shown only detects gamma emitters. It makes a good random number generator, I guess.

How can these devices be tested to check that they are working properly ? I supose that to test them you need any kind of radiation source ?

To check these devices, you may (1) measure background ionizing radiation level. But, if you want to calibrate your own, also you can (2) do this against another trusted and certified device. And at last, of course (3) well calibrated radiation source may be used.

Please be kind and respectful to help make the comments section excellent. (Comment Policy)

This site uses Akismet to reduce spam. Learn how your comment data is processed.

By using our website and services, you expressly agree to the placement of our performance, functionality and advertising cookies. Learn more