Once you have a track and a kart to race on it, what’s missing? A lap counter that can give your lap times in hardcopy, obviously! That’s what led [the_anykey] to create the Arduino-based Lap Timer to ...

A typical reflective object sensor consists of an infrared light emitter diode (IRED) and an NPN silicon phototransistor mounted side-by-side on parallel axes in a compact black plastic housing. The ...

Here is the circuit of a little label sensor ideal for detecting labels on bottles. The circuit offers a peak sensing distance of 2.5 mm (operating range 0.2 mm to 15 mm) backed up by the proven ...