Frequency Counter



counter_photo
Simple Frequency Counter


Counter_schematic
Counter schematic.


LCD
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: counter.zip

The original PIC assembly source code for the RadCom Oct 2006 frequency counter is here: counter12.zip

100mS gate time version for use as a frequency display in a receiver/transmitter:
display.zip

Counter
Counter PCB top view.


Component_Overlay
PCB component overlay.


PCB_Tracks
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. counter21.zip

Version 2.1 for 10.000MHz clock. Dec. 2007. counter21-10MHz.zip




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.
gpscount.zip
GPS_gate_version
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
SDEC SSC2D16DLYY


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