Game cubes consist of 4 wooden blocks. Primery box with LED display, slave box connected by RF link and two secondary boxes connected only with IR signals. Pairs of boxes are connected with 5 IR lines, with which we can detect passage. The two pairs are connected with CC1101 wireless module. Each box has a 2S LiPo battery and a soft power button. On primary box is an LED display. Boxes are controller with power buttons.
Because IR signals travel everywhere, only one line can be active at a time. A pause has to be made between pulses, because TSOP1838 used for IR detection has a bit of delay. Because of sun interference we need metal tubes in front of LEDs and sensors.
Cubes have 3 modes: goal counting, stop watch and alarm.