The Device

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

The Geiger tube is excited by mildly radioactive pebbles (see images below). While precise readings (measured in µSv/h) are displayed on the OLED screen, a creative approach was taken to visualise the data on the LED matrices. The horizontal matrix shows the immediate radiation dose detected by the Geiger tube, while the 8x8 matrix shows the total accumulation over time.

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

The Visualisation

Three separate visualisation modes were developed to display radiation accumulation:

• Radial mode - the circle inside the matrix grows as the accumulated radiation increases.
• Spiral mode - the spiral inside the matrix expands with the accumulated radiation.
• Sine mode - the radiation accumulation is represented by a sine wave that increases in frequency and amplitude.

These modes can be toggled by pressing the button on the side of the device or by tilting the device sideways until the accelerometer registers a 90-degree tilt.