fault-finding

Infrared (IR) transmitters and receivers are vital components used in many electronic pinball machines since 1987. Commonly referred to as ‘opto-switches’ or simply ‘optos’, paired-up transmitters and receivers allow contactless sensing of movement in order to register a target hit, detection of a ball’s position or the sensing of movement by a mechanical device. However, [...]

Welcome to the second part of Todd Andersen’s article detailing how to build and program an infra-red (IR) tester transmitter and receiver. The first part showed the components used, why they were selected, and how to connect them to build the two devices. Now it’s time to program the microcontrollers to pulse the IR transmitter’s [...]