Thursday, October 14, 2010


Inductance and Capacitance Meter using Microchip's PIC18F2550 connected to USB using HID class (Plug-n-Play).

* f1, f2. and f3 are the frequencies defined by the equations stated on Digital LC Meter.

diagram using internal Analog Comparator and Timer Peripherals of PIC18:

schematic with actual values:
*simulation on Proteus 7 is NOT working (particularly the LC oscillator part and internal pull-up on RB0)

download link (HEX and PC app): forum link:   PIC18F2550 USB LC Meter

 # edit (10-20-10)
added "Calibration option" ( same PIC18F firmware )
  • reference capacitance range is 1.0nF +/- 5%
  • Fosc (20MHz crystal with PLL) frequency range is 48MHz +/- 200ppm

# edit (08-14-11)
 V1.2 ->  updated host-side application,
          -> should now work both on 32-bit OS and 64-bit OS hosts.