Measuring low level cap/inductance and stroboscopic mode
The scheme we have used so far to measure capacitor is to generate a square pulse and capture the voltage waveform. For reference, the STM32/GD32 MCUs have very decent 12 bits ADC that can go down to ~ 0.5/1us sampling frequency. For capacitors, the time constant of the waveform is proportional to Resistor*Capacitance, so if we use the bigger resistance (470k) we can have a few points even with very small caps. NB: The waveform is V*(1-exp(t/RC)), so with 2 known points we can calculate R*C. Since R is known , C can be computed. It gets problematic with inductance. The time constant is proportional to L/R, so with the smallest R (470 Ohm) and 100 uH inductance that leads to time constant in the order of ~ 100E-6/470= 200 ns, which is way too small compared to the ~0.5/1 us resolution of the ADC. Additionally, we need at least something like 5 points to have a valid guesstimate. So we are out by a factor of 10. I've been scratching my head on that one for some time and finally