1 MHz frequency counter using discrete CMOS ICs
Miguel Pedroso constructed a digital frequency counter using CMOS 4000 series logic chips to participate in the Dangerous Prototypes’ 2012 Open 7400 contest. It can measure frequencies up to 999.999 KHz.
Frequency counter using CMOS 4000 series logic chips
The project uses six 4029 4-bit counter ICs that are cascaded and configured to work in the BCD decade up counters. The measured frequency is displayed on six 7-segment LEDs, each driven by the 4511 BCD-to-Seven segment driver chip.
Via: Dangerous Prototypes