The Device

The Geiger Counter was prototyped as physical computing project to teach school children physics, specifically radiation. The Geiger Counter has a J305 Geiger tube, an Arduino Mega, Monochrome OLED screen, and two types of LED matrices.

The Geiger tube is excited by very mildly radioactive pebbles (refer to images below). While the precise readings (measured in µSv/h) are shown on the OLED display, a creative twist was taken to visualise the data on the LED matrices. The horizontal matrix shows the immediate radiation dose absorbed by the Geiger tube, whereas the 8x8 matrix shows the total accumulation overtime.

The case was designed using Rhino 6 and then 3D printed with an Ultimaker 2.

The Visualisation

In total three separate visualisation modes were made to show the radiation accumulation.

• Radial mode - the circle inside the matrix grows along with the accumulated radiation
• Spiral mode - the spiral inside the matrix keeps getting bigger with the accumulated radiation
• Sine mode – the radiation accumulation is represented by a sinewave that increases in frequency and amplitude.

The three modes are toggled by pressing the button on the side of the device or by tilting the device sideways until the accelerometer registers that the device is tilted 90 degrees.