Simple Frequency Counter
Connections to LCD module.
This is the support page for the simple frequency counter project in Homebrew, RadCom October 2006.
The original design used a gate time of one second which gives a count resolution of 1Hz. Maximum
input frequency is about 50MHz. A VHF/UHF prescaler for this counter is described in Homebrew, RadCom
February 2008. U2 is a PIC16F628 (PIC16F628-20 or PIC16F628A). The PIC crystal frequency is 10.240MHz.
The firmware is easily modified so that a 10MHz crystal can be used instead.
Homebrew for March 2008 shows how this counter can be used with a GPS or Loran controlled gate.
PCB artwork for the RadCom frequency counter can be found here:
The original PIC assembly source code for the RadCom Oct 2006 frequency counter is here:
100mS gate time version for use as a frequency display in a receiver/transmitter:
Counter PCB top view.
PCB component overlay.
PCB track pattern.
Updated version 2.1 for RadCom Homebrew Feb. 2008 with gate times of 0.4S, 4.0S, 1.28S and 12.8S
Pic clock frequency = 10.240MHz.
Version 2.1 for 10.000MHz clock. Dec. 2007.
This is a hacked version of the counter firmware which allows the counter gate time to be determined by a 1pps signal
from a GPS or Loran receiver. More details in Homebrew, RadCom March 2008.
GPS controlled version measuring the frequency of a 10MHz OCXO using a gate time
of 200 seconds.
These display modules have been tested and found to
work perfectly with the counter:
Maplin 2x16 display. N27AZ. Samsung chip.
Densitron 2x16 with Oki M6222B chip.
Generic unbranded 2x16 with Hitachi HD44780 chip.
Winstar WH1602A 2x16
L2432 2x24 LCD module.
Powertip PC 1602-F
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