As I was writing then, assembling it was a breeze, even though the kit I had, courtesy of BroHogan, was version 1.0. The Geiger counter worked nicely as soon as I powered it from (approx 5V) battery: the buzzer clicked and the LED flashed, even faster when the radioactive mantle was nearby. And this is where I stopped.
But the DIYGeigerCounter kit also offers the smart option of interfacing with an on-board microcontroller, specifically ATmega328, thus making it the cheapest Arduino-based Geiger counter available (compared to the Radiation shield from Libelium or Geiger counter from Sparkfun).
To finish this project, all I had to do was:
- connect the LCD display as detailed here;
- compile the software, provided here, and upload it;
- find or make a practical enclosure;
- assemble everything together.
The result is shown in the photo below.
The case is a cheap and sturdy plastic box, branded "Really Useful Box, 0.55 liters", bought a few years ago from Staples (it may still be available for sale). The lid is tightly held in place by the two blue side-handles.
A prototyping PCB provides the base for the main board, the LCD and the Geiger tube (I also added an FTDI connector, for software upgrades). The batteries, 4 rechargeable AAs, are connected to the board through a toggle switch (on the left side).
Should make for a handy Geiger counter anytime I get solicited by friends :)
A future extension (but realistically, a new project) would be adding logging capabilities, as documented here.