Arduino counts per minute calculator?

Hello. I found a really simple schematic to make a Geiger counter clicker. For when I want to get the CPM, can I just override the clicker/LED and connect it to the Arduino for CPM calculation?


Without seeing the schematic there is no way anyone can tell you.

Here's the schematic:

Connect the junction of the BC517 and the speaker to an arduino input. Also connect the ground to the arduino ground. If you want to remove the LED and the speaker then replace them with a wire connecting the collector of the transistor to the junction of the resistor and capacitor.

Thank you Grumpy_Mike.


I've been writing Geiger counter SW for quite a while now. Indrek's circuit should work with what i have, when connected as Mike suggested. (It would connect to INT0 - pin 2) Your welcome to take a look at it on this page.

It uses a rolling average for CPM, and has lots of goodies. I expect it should just drop in. Should give you some ideas at the least. John

Thank you. Will it work with Uno?

Yes it will.