https://github.com/robcranfill/faker-counter

A fake Geiger counter!
https://github.com/robcranfill/faker-counter

adafruit adafruit-feather circuitpython raspberry-pi-pico

Last synced: about 1 month ago
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A fake Geiger counter!

• Host: GitHub
• URL: https://github.com/robcranfill/faker-counter
• Owner: RobCranfill
• License: gpl-3.0
• Created: 2023-10-16T16:16:47.000Z (over 1 year ago)
• Default Branch: main
• Last Pushed: 2023-11-23T18:02:44.000Z (about 1 year ago)
• Last Synced: 2024-12-20T01:44:23.768Z (about 1 month ago)
• Topics: adafruit, adafruit-feather, circuitpython, raspberry-pi-pico
• Language: Python
• Homepage:
• Size: 13.5 MB
• Stars: 1
• Watchers: 2
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

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README

        
# faker-counter

A prop Geiger counter.

This is a fake Geiger counter I used as part of my Halloween costume in 2023. I went as "Oppenclimber",

a mashup of J. Robert Oppenheimer (suit & tie, fedora, pipe, security badge, radiation goggles) and a 

rock climber (climbing harness & gear). I also carried this device, which has a speaker that plays actual

digitized sounds of a real Geiger counter at two different levels: a "background" level of a few quiet clicks,

and a "high" level of crazy clicks; the level is controlled by a somewhat-inconspicuous button that you push 

while pointing a "sensor wand" that actually does nothing. It also has two LEDs - green and red, for low and

high levels - and a little analog voltmeter whose needle swings in accordance with the clicking.

### Hardware

* CircuitPython microcontroller (needs to support I2S for audio - 3 GPIO pins)

  * The prototype, on a solderless breadboard, used an [Adafruit Feather RP2040](https://www.adafruit.com/product/4884).

  * The second, final, version used a [Raspberry Pi Pico](https://www.adafruit.com/product/5544).

    * The only downside to the Pico is that the onboard storage was so much less, I had to create downsampled versions of the audio files. Which still sounded fine - you don't need much bandwidth for a bunch of clicking!

* 3 watt I2S audio amp, such as an [Adafruit MAX98357A](https://www.adafruit.com/product/3006)

* Push button to increase click rate.

* Surplus analog voltmeter, 5 volts full scale.

* Green LED for low activity, red LED for high.

* Small speaker. I used an [Adafruit 3W 4 Ohm speaker](https://www.adafruit.com/product/4445)

* 3 resistors, 1 diode, 1 capacitor (see schematic below).

* A box; I used a second-hand cash box.

* Some kind of speaker grill to hide the hole in the box. I used a piece of open-cell foam.

* USB battery pack.

* Old broken non-contact voltage tester as the "sensor".

* A nice braided USB cable as the "sensor" cable.

* Stickers! I also created artwork which I then printed at a local photo kiosk and glued them on.

* [Solderless breadboard](https://www.adafruit.com/product/64) & [leads](https://www.adafruit.com/product/153), or ["perma-proto" board](https://www.adafruit.com/product/1609) & solder.

### Circuit Diagram




### Software

CircuitPython (version 8.2.7 used), of course! Plus the code included here. There are no additional Python libraries to install!

# Finished Project

























# References, Notes

* Thanks to [Paul Price](https://www.eevblog.com/forum/projects/build-an-analogue-vu-meter-with-a-normal-voltmeter/msg872064/#msg872064) for the VU circuit.

 * It's not as loud as I'd like. In my Halloween party setting, it was just loud enough.