INTERFACE RASPBERRY PI CAPACITANCE METER

摘要

The original intention for this month's Interface article was to feature a capacitance meter circuit that was essentially an analogue project from the distant past, but which would connect to a Raspberry Pi computer via an analogue-to-digital converter instead of simply driving a moving coil meter. This gave the setup outlined in the block diagram of Fig. 1. The design is based on a monostable circuit that has the test capacitor as one section of the CR timing network, and several reference resistors in the other section.