A bit of thought led him to build a reflective sensor which can measure the spinning of a wheel (translated). He got his hands on an infrared phototransistor which had been used as part of the ...

The first try at this used an OBP732 reflective transmitter and an ATtiny202 ... so [Ido] had the idea to use the sensor for wireless IR programming. The microcontroller on version two was ...

This was then reduced using sodium borohydride to generate a black substance that retained its reflective properties ... a mirror-based sensor and a 360-degree rotating type sensor.

The E3AS-HF Time-of-Flight (ToF) sensor offers reliable detection from 5 cm to 6 m with a unique angle characteristic for greater installation flexibility OMRON Industrial Automation launches the E3AS ...