The simplest frequency meter (counter) up to 10 MHz
AVR Frequency Counter
Timer and Counter in AVR Atmega32A Microcontroller
Projects - AVR - Reciprocal Frequency Meter
JA2GQP's Blog: AVR Frequency Counter
Control AVR 8 bit Timer-Counter0 using AVR-GCC - Do It Easy With ScienceProg
Avr Atmega Atmega1632 Timer | Avr Atmega
Tooarts 10MHz Frequency Meter DIY Kit Frequency Counter AVR Frequency with Shell Counter Cymometer Frequency Measurement 0.000 001Hz Resolution : Amazon.in: Industrial & Scientific
40MHz-Frequency counter with ATmega8
Amazon.co.jp: KK moon 10 MHz Frequency Meter, DIY Kit, AVR Frequency Counter, AVR Frequency Shell Counter Simometer, Frequency Measurement, 0.000, 001Hz Resolution : Industrial & Scientific
Frequency counter
JA2GQP's Blog: AVR Frequency Counter
10 MHz frequency meter (counter) III. with 0.000 001 Hz resolution
10MHz High Accuracy AVR Meter Frequency Counter with Measurement Resolution D4B8 | eBay
8 MHz frequency meter using AVR microcontroller - ATMega32 AVR