Frequency Counter Kit revisited: higher resolution and RPM mode

This video is about another change in the firmware of a PIC micro controller based frequency counter and crystal tester in kit form sold on the internet under many names, for example "1Hz-50MHz Digital LED DIY Kits Crystal Oscillator Frequency Counter Tester".

In previous videos, I described modifying the hardware to change the horrible "crystal oscillator tester" part into a pre-amp for the counter and how to improve readout resolution in the Khz range. These videos are Changing the hardware: https://youtu.be/0BxpMm6SLoE Changing the firmware: https://youtu.be/8rOCmhPWLWw

In this video I show a firmware modification that adds high-resolution frequency measurement in the range up to 100Hz and allows the readout to be switched between Hz and revolutions-per-minute (RPM). The max. range in RPM mode is about 15300 RPM.

The firmware (previous and latest version) as source or HEX file can be downloaded here: https://github.com/TheHWcave/PIC-freq.counter-modification/ ... https://www.youtube.com/watch?v=0D6EcgTQtNw