This project began a long while ago, when electronic parts were still available in local stores.

I used a counter made from 2 counter chips and decoders (4553 and 4511).

The user interface was made with logic ICs

The circuit was built on prototype perfboard with #40 AWG magnet wire (point to point).

The sample time is 1s (1Hz) or 10s (0.1Hz) derived from an 8 MHz oscillator. The sampling is displayed on the front panel.

There are 4 modes selectable with 4 buttons:

1) frequency meter

2) period meter

3) chronometer (when signal is high)

4) counter

There is no microprocessor, no programmable logic.