PIC16F84-Based Frequency Counter

The frequency counter is built around a PIC16F84 microcontroller for the frequency range of 100Hz to 2.5GHz.

The device utilizes an LCD with 16 characters in 2 lines and 12.8MHz TCXO with 1ppm. The input signal has a voltage value of 0-510mV which is indicated in the LCD which makes the tuning of the coil to be conducted while checking the frequency. The project can be applied for the display of frequency of the homemade transceiver since it was furnished with IF offset function. The frequency counter was constructed in a small board size of 100mm x 43mm.

The LCD can be easily disconnected with use of the 20-pin connector that is attached with the LCD. The RF signal input is passed through the BNCs which are soldered directly on the PCB while all of the parts are assembled to one body.

The IF offset is done by pushing the tact SW for RB7 while the carrier frequency of the SSB generator is being measured. This will show “ADJ” in the LCD. Pushing the tact SW for RB7 twice will show “OFF” in LCD. The display figure with IF offset is made after powered off.

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