I'm currently trying to figure out how the Arduino Capacitive Sensing Library works. There is already a similar, but more general question: How does the Arduino CapSense library work? The answers there explain that it's a RC circuit and therefore, there is a RC time constant which depends on the capacitance C. So if C changes - i.e. a human finger is in proximity of the sensor metal plate - there is a different time measurement.
- Does this "capacitor" (sensor metal plate + human finger) get fully charged/discharged? (What does that even mean in this context?)
- I'm thinking yes because if I'm imagining a huuuuge sensor plate that can store lots of charge, wouldn't that be like shorting it to GND? Then, the input pin would never change.
- How important are the additional capacitors "to improve stability"?