In my previous design idea, a design for a simple GPS disciplined oscillator (GPSDO) 10 MHz reference was presented. A note at the end of that article describes the realization that a frequency ...

The project utilizes an AVR controller that can be used as a counter by being more involved with a PIC which has synchronous counter input. The PIC input can handle frequencies up to 40MHz.

The prescaler described here connects to the front end of a 100-MHz frequency counter to extend its coverage range to 10 GHz. The circuit is a far less expensive way to measure frequencies above 100 ...