Raspberry Pi 3 used as environment radioactivity monitoring station

Recently I've found Pi-GI, it's an open source project of a radiation monitoring system based on Raspberry Pi, and (open source hardware) Geiger-Muller detector. Statistics are available through a web page, so it's possible to use it conveniently on a PC, tablet or a phone. It's written in python.

Today I will present how I've glued together this software and my Geiger-Muller counter described in my previous posts.

Below is a circuit of my counter, it uses 5V power supply and draws a couple of mA, so it's possible to power it directly from Raspberry. Since originally I've used three tubes in parallel, I had to remove two of them to not have values multiplied by three - most of the detectors and software for them uses only one tube.

Raspberry Pi requires 3V3 logic on GPIO ports, fortunately, that's not a problem here, pin 3 of SV3 socket just needs to be connected to 3V3 rail on the Raspberry Pi. The output (pin 2 of the same socket) needs to be connected to one of the GPIO pins. It's a bit confusing, because on the webpage the circuit states that GPIO0 is used, but in the current version of the software GPIO4 is used instead. The pin can be configured in software by editing gpio_port variable in PiGI/software/conf/default.cfg

Software installation and configuration is presented in this article, in addition, because I use STS-5 tubes, I had to change the tube type in PiGI/software/conf/default.cfg - SBM-20 has almost the same parameters as STS-5.

 60 # See: https://apollo.open-resource.org/lab:pigi:common-geiger-tube-parameter
 61 tube_id = SBM-20
 63 # GM tube specific cpm to microsievert/h conversion factor
 64 tube_rate_factor = 0.00277

Application starts by default on 8080 port, so logs are available by the web on http:/[IP of the Raspberry Pi]:8080 address. By default it starts in simulation mode, to change it and get real values, it's needed to change in http://[IP of the Raspberry Pi]:8080/webGI/index.html#serverOptionsPanel source to "environment".

That was all, now I'm able to monitor radioactivity just from my browser!

On the picture above, you may see an increased radioactivity level, I've placed smoke detector containing a radioisotope of americium on the GM tube, at the end is visible big decrease, this is because I've taken the smoke detector out, so only environmental radiation was present.

The value drops to 20-25 pulses per minute, that's normal value for environmental radioactivity - it's mentioned in the tube datasheet.