The project shows you how to build simple and powerful frequency meter using ATtiny2313 microcontroller. The frequency meter can be used to measure frequencies from 1Hz to 10MHz (9,999,999 Hz) with a resolution of 1 Hz over the entire range. It displays result on seven 7-segment LED displays. The project uses 22.1184MHz overclocking crystal to achieve 10MHz measurement range.
In this project, AVR chip counts pulses on the input given at the time of 1 second and displays the result. The project uses two timers: 16-bit Timer1 in CTC mode and 8-bit timer counter which counts pulses given to its input (T0 pin). Download: schematic & source code.