Optical sensor for PC (CB20548E)

This circuit was found in a PC documentation from 1996. It can be used as a shield with modern microcontrollers.

Trinkets Adafruit (COM029E)
July 2016 - It can be obtained from Mouser Electronics new trinkets Adafruit. These trinkets are...
Resistance to voltage converter (CB9597E)
This circuit allows you to read resistors up to 20 M ohms, converting it into voltage. The circuit is...
Acoustic Remote Control (CB17667E)
In fact, this is the circuit also known as “vox”, that is, a relay triggered by sound. This...