Success! building Zythian into a Geiger counter!

I fooled with this project for the last few months, and I think I’m finally satisfied.

My only complaints could be solved by a RPI 4. Namely, I can’t seem to find a battery pack that can provide the RPI3 with enough voltage and assume any USB-C power could solve this. If anyone has any suggestions for a PowerPack that can give the RPI what it needs please share!!
It will turn on and play but I get the CPU-overload warning allot and stuttering unless plugged directly into the wall, which isn’t ideal seeing as I want to perform on a sidewalk… Also I want more cpu power overall, but that’s just so I can play with layering more effects and such.

Awesome project guys! I eagerly await RPI4 software.

PS. if you were curious, the other Geiger counter is a self contained portable amp, with it’s audio output split to a portable 1986 TV that I hacked into an oscilloscope.


That looks :radioactive: FANTASTIC! :radioactive: Congratulations!
I love that vintage VU meter and the 1986 oscilloscope. :grinning:
Thanks so much for sharing!

I’ve used those chunky 23000 mAh power banks and not had problems. It’s probably worth experimenting with a few different cables. I’ve found some usb cables to cause power problems over others.
Also, That case. WOW, what a cool thing!

Aaah the hacked tv oscilloscope…

Drive the deflection coils using an amp…
We used to have a suitably butchered TV that we put on stage during disco’s ( yes that’s what we called them, get over it…), to amuse and entertain the audience. We twisted the tube so the trace displayed horizontally.
But keep your hands away from the tube even after the beast had been turned off…

My mate Andy found the details in Practical Television magazine…

Awesome Zynthian, my friend!! Congratulations!!

FYI, RBPi4 software is already available for Zynthian. You only need to download the Buster RC-1 or the latest “green” nightly build…


It is important to supply 5V at 2A or more. If there is too much resistance in the power cables or connectors then the current will be limited resulting in lower voltage at the RPi. Your problem is likely to be poor cables or connectors. I have a 5V UPS which I tried to connect directly to the RPi header pins but that failed due to thin jumpers and / or poor crimps. I will try thicker multi-strand cable and better crimp connection. It works well with a high quality micro-USB cable but fails with lower quality cables. The battery pack must be capable of delivering at least 2A. You can check by measuring the voltage at the battery and at the RPi. If it is 5V at battery but significantly lower at the RPi then the interconnects are suspect. If it is low at the battery then the battery is suspect. Good luck and remember to use appropriate protection, e.g. full hazchem outfit :grinning: :radioactive::warning:

1 Like

Right, I was very aware of the flyback transformer and the ~15,000 volt capacitor. It would be a dumb thing to die for…

Hmm… It could be the Micro-usb extension I’m using from the RPI3 to the outside of the case. It must be since I’m certain that Powerblock I’m using outputs 2.1 amps at 5v, also I’m using a known good USB cable from the battery to the case.

I could just plug the known good cable through the case and tie it off as a permanent power cable… that would be the easy cheap option.

Are the pinouts the same? After some initial setup through the web app, would it be fairly plug-and-play? There may already be a post about this, I will look for it now.