Surprisingly Accurate Digital LC Meter

This is PIC16F628 and pic16f84 base inductance/capacitance meter design by Phil Rice VK3BHR.Measuring range is from 0 to >0.1uF for capacitance and 0 to >10mH for inductance.Expected accuracy is +/- 1% of reading +/- 0.1pF or +/- 10nH.This project is a combination of two stolen designs.The oscillator design originally came from the AADE LC meter web page. It uses an LM311 comparator with positive feedback to make a parallel LC oscillator with digital output. It seems to oscillate readily over a wide range of L and C values. Hopefully, it follows the “well known formula for resonant frequency”.The frequency measuring part is a cut down version of the September 2002 Frequency Meter article from Amateur Radio magazine. The original idea for this came from the web pages of Eamon Skelton, EI9GQ.
Surprisingly Accurate Digital LC Meter - [Link]