Capacitor

Arduino library to measure capacitance from 0.2pF to over 100uF with no external hardware.

Introduction

This library allows capacitance to be measured between two pins. One pin must be an analog pin.

Declare a Capacitor object, e.g.:

Capacitor cap1(7, A2);

To measure the value of a capacitor (e.g. in the case above between pin D7 and A2) call the Measure() method, e.g.:

float val = cap1.Measure()

Returns the capacitance in picofarads, in this case in the variable val.
(note that 1nF = 1000pF and 1uF = 1000000pF)

I originally came up with this idea back in 2014. For some explanation of how it works please have a look at these links: https://hackaday.com/2014/01/22/capacitance-measurement-with-the-arduino-uno/#more-113173 http://wordpress.codewrite.co.uk/pic/2014/01/21/cap-meter-with-arduino-uno/ http://wordpress.codewrite.co.uk/pic/2014/01/25/capacitance-meter-mk-ii/
When I get a chance I'll update the Wiki with some of the above information and some oscilloscope screen shots...