The Weeder Frequency Counter using PIC16F84

This is a port by Peter Cousens to the PIC 16F84 of the  50Mhz Frequency counter kit {originally available} from Weeder Technologies . Since it uses a base PIC that is easily programmable, and provides a usefull bit of bench test equipment at very low cost, it makes an ideal PIC learning project. If you don’t want to spend the time on the PCB, collecting the parts or even not programming the uP, you can order the kit (for a very resonable price) from

Weeder Frequency Counter

News: Weeder Tech no longer makes this kit. They have moved on to a very nice version that works with a local PC via the serial port for display and control. It is also “stackable” for multiple counters at once or with other modules for control and measurement of all kinds. See for more information. The original kit has been licenced to Invent Electronics and Ken has made some improvements and provides a very nice (closed source) kit for $49 and a PCB for $10 (prices as of 2004/03/05)

The result is a nice frequency counter that reads frequency from 1 Hz to 50 MHz and displays it on a 16 character LCD display. Auto-range feature provides floating decimal point and automatic placement of suffix (Hz, KHz, or MHz). Gate speed automatically decreases to one second below 100 KHz to display frequency with a resolution down to an amazing 1 Hz.

  • Auto-ranging with floating decimal point.
  • Up to 7 digits displayed.
  • Auto-adjusting gate speed (0.1 sec to 1 sec).
  • Microcontroller-based circuitry provides for simplicity, ease of assembly, and highly stable readout.
  • Sensitivity approximately 100 mV RMS (100 Hz to 2 MHz), 800 mV RMS @ 50 MHz.
  • Input overload protected.


For more detail: The Weeder Frequency Counter using PIC16F84

About The Author

Ibrar Ayyub

I am an experienced technical writer with a Master's degree in computer science from BZU Multan University. I have written for various industries, mainly home automation, and engineering. I have a clear and simple writing style and am skilled in using infographics and diagrams. I am a great researcher and is able to present information in a well-organized and logical manner.

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