ZEFI, a very simple frequency indicator.

The ZEFI (Dutch: Zeer eenvoudige frequentie indicator) is a simple frequency indicator using a PIC 16C84 microcontroller for determining VFO frequency, correct for IF, and display the last two digits of the frequency in kHz using 8 LED's arranged as follows:

50 o o 5
40 o o 4
20 o o 2
10 o o 1

The microcontroller can store relevant parameters for two bands. Programming these parameters is explained in the source code. The schematic is quite simple. You will probably need some sort of VFO buffer/amplifier. I modified the amplifier that Wayne, N6KR, used for his KC2. This is not critical. Anything that isolates the ZEFI from the VFO and that has enough amplification to make the ZEFI count will do.

After trying out the circuit and program on a breadboard, I built the ZEFI into my NORCAL Cascade 80/20m SSB transceiver. The front panel has ample room for the eight LED's. I built the ZEFI on a small piece of veroboard in a small PCB box to screen microcontroller noise.

I have prepared two zip files, each containing the PIC source code and a ready to load hex file:
a version for the 16C84
and one for the 16F84

If you have comments, please let me know. (email address is on my home-page)

Thank you !

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