C Meter click is first of a series of click boards meant to be used as tools. This one is for measuring the value of capacitors.
C Meter click is based on a NE-555 precision timer IC. A popular chip that has been in continuous use for decades. We wrote more about it in the post about Pulse click.
On C Meter, the NE-555 is employed as an astable multivibrator with swappable capacitors. The board has four 5 slots for placing capacitors (four sizes for SMD caps and one socket for thru-hole). Any capacitor you place will impact the frequency of the square wave that NE-555 outputs through the interrupt pin.
Since there's a colleration between the value of the capacitor and the outputted frequency, you can use a simple algorithm to determine the exact value of the capacitor you are testing. After you're done, remove (unsolder) the capacitor you tested and reuse C Meter click the next time you need it.
This is a novel concept, a click board that substitutes much more costly capacitance measuring equipment. Similar clicks that can be used as tools are coming up.