Geiger Counter

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A man named Ted Violett was my "science father" and family neighbor when I was a boy in the small town of Gunnison Colorado. He taught physics at the local college where my father also taught. He would, from time to time, share some neat gadget or technology with me and contributed to my love of electronics. One time he loaned me a Geiger Counter for a little while and ever since that time I've always wanted to own one. Decades later, I finally decided to build one. For no good reason other than it's fun to find those things that emit an unseen energy.

Some pictures and a little info here. The full design and documentation may be found on Github.
Hardware Components
  • LND712 Geiger Müller Tube
  • High Voltage board from RH Electronics
  • TTGO Lilygo T-display ESP32 dev board with 135x240 pixel LCD display
  • Hand built power switch with RGB backlighting
  • Hand built 555-based audio click generator
  • ICR10440 3.7V Lithium Ion rechargeable battery

3D printed enclosure with design done in OpenSCAD. Sanded and painted.
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Firmware Features
  1. Theoretical range of 0 - 10000 Counts/Second (CPS) with autoscaling and dynamic averaging for responsive Counts/Minute (CPM) displays
  2. Displays immediate and accumulated dosage
  3. Displays Counts and roughly estimated Sivert values
  4. Provides a mode to accumulate over a specified period
  5. Mute control
  6. Battery level or charge indication

C firmware using the LVGL GUI system for graphics and built as an Espressif IDF project.