I need to sample several high-impedance circuits using the analogue pins (using the Arduino Nano).
Primary requirement is low component count and cost. Bandwidth requirements are very low. This means that I'm ruling out using op-amp buffers, etc.
According to this post
, input impedance is about 100MOhm, but the charging of the sample-and-hold capacitor and multiplexing bring this down considerably, initially.
This begs the question, how can I programmatically work around this? In other words, is it possible to tell the microcontroller to switch the multiplex switch, sample and hold, wait a while, and then take a sample? How would I do that?