LVA Geiger Counter v1.5/2.0/2.1 source code

This is my fork of MightyOhm's Geiger Counter. It features:

• v1.0 (this is the original counter kit from MightyOhm):

  • An Atmel-based geiger counter, supporting various GM tubes, like SI-3BG, SI-1G, SBM-20, STS-5, and others, with a tunable 300-600V tube bias voltage supply on-board;
  • LED and piezo notification on each detected particle;
  • Serial interface so you can connect it to Arduino, Raspberry Pi and the like, for data gathering and internet hookup. The serial data is easily parsable, in the form of a 1-line per second log, and includes both counts per minute (CPM), as well as equivalent dose (in µSv/h).
  • Pulse header: outputs a 100 µs active-high pulse on each detected particle;
  • ICSP header
  • Powered by standard 2×AAA batteries; lasts more than a week on a single pair of alkalines.

• v1.5

  • A 7-segment screen, for easy radiation readout. The device can now be used as a generic portable dosimeter;
  • "Pure GM Counter Mode": the device displays the total particles detected since startup;
  • 3-level display brightness setting (and can be turned off if you need to save power).

• v2.0

  • MCU changed to ATmega88, much more code space to play with (ATtiny2313 was really tight on program memory);
  • Much brighter display, directly controlled by the MCU;
  • uSv/h <-> GM counts mode is freely toggled with the button;
  • 9-level display brightness setting;
  • Battery level monitoring, including an alarm tone if the batteries are nearly flat.

• v2.1

  • PC link protocol: the device can be hooked up to a PC via a serial link (e.g., using a USB-to-UART convertor like the SparkFun's FTDI Basic). Using that protocol you can:
    • Fine-tune the GM tube sensitivity, instead of the fixed "57/100" value used in earlier firmwares;
    • Set up alarms if the radioactivity exceeds a certain level;
    • Set up and download radiation logging.
  • Logging feature: leave the Geiger Counter turned on somewhere and it will accumulate statistics for the radiation level over time. The log data is stored in the ATmega EEPROM, so it's saved even in the event of a power loss. The gathered data can later be downloaded via the PC link, and you can graph it over time, producing charts like this.

Hardware

The device is sold through our friends at Robotev, see here if you want one (currently shipping to Bulgaria and Balkan-area countries only). More photos of the device can be found here.

Links

See the FAQ (in Bulgarian), and an useful page, which discusses the statistical uncertainity when measuring low radiation levels (e.g., the background levels in most areas) for just a minute; in includes a helpful procedure for more precise measurements, and a shot noise calculator to facilitate the process.