Summary of The Weeder Frequency Counter using PIC16F84
This article describes a low-cost, PIC 16F84-based frequency counter project ported by Peter Cousens. Originally from Weeder Technologies, it measures frequencies from 1 Hz to 50 MHz with auto-ranging and automatic decimal placement on a 16-character LCD. The device features adjustable gate speeds for high resolution and input overload protection. Due to discontinuation by the original maker, Invent Electronics now offers an improved version of the kit and PCB.
Parts used in the Frequency Counter:
- PIC 16F84 Microcontroller
- Weeder Technologies Kit (Original)
- Invent Electronics Kit (Improved Version)
- PCB (Printed Circuit Board)
- 16 Character LCD Display
- Microcontroller-based circuitry
- Serial Port Interface (for new stackable versions)
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 http://www.weedtech.com
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
http://www.weedtech.com 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
- What is the frequency range of this counter?
The device reads frequency from 1 Hz to 50 MHz. - Can the display show different units automatically?
Yes, it provides auto-ranging with floating decimal point and automatic placement of suffixes like Hz, KHz, or MHz. - How does the gate speed adjust?
Gate speed automatically decreases to one second below 100 KHz to ensure a resolution down to 1 Hz. - Is the input protected from overload?
Yes, the circuit includes input overload protection. - What microcontroller is used in this project?
The project uses the PIC 16F84 microcontroller. - Who currently sells the improved version of this kit?
Invent Electronics licenses the design and provides the improved closed-source kit and PCB. - Does the newer version support PC connection?
Yes, the newer stackable versions work with a local PC via the serial port for display and control. - What is the sensitivity of the counter at 50 MHz?
The sensitivity is approximately 800 mV RMS at 50 MHz.
