This device tests your balance as you stand on it, providing you with data on how much time you spent off-centre and the greatest tilt each way (left/right). It's much harder than you think!
It's made from a bookshelf, with 3D-printed curved sections attached to the base. A microbit has been fitted to the underside using a 3D-printed clip. The microbit measures the orientation of the board constantly, determining the angle from the vertical. This is monitored over a short period (say 30 seconds) and integrated to give a total value for lurch to the left and lurch to the right, and well as the largest angle measured each way.
The readings are then sent wirelessly to another microbit using the radio function. This second microbit can be connected to a USB port, so the data can be displayed on a PC.
This setup measures how long you can stay in the air! Jump as high as you can, but you must land in the same spot.
It uses an Arduino Uno with a light-sensor connected to an analogue pin. A torch placed opposite the sensor creates a simple 'light gate'. The Arduino is programmed to measure the time interval between the flash of light as the athlete lifts off the ground and the dip in light-level as they land again. The interval (in ms) is displayed on a laptop, which is connected to the Arduino via a USB connection.