/FrequencyTester

Simple frequency tester based on ATMega8 and external logical counter as prescaler. Created for my dad.

Primary LanguagePython

Frequency tester based on ATMega8 and counters

Created for my dad.

It supports frequencies up to around 10 MHz. Something wrong with hardware/software to beat that right now.

Image of the finished tester case

Hardware

Schematic

Microcontroller: ATMega8
Display: SPLC780D based 1x8 display. Simple custom small library used.
External Prescaler counter: 74HC93E, 4-bit fast binary ripple counter

Extra transistor (2N3903) and Schmitt's gates (74HC132N) used to try to fix the signal into clearer square wave.

Notes

Inspired by 40MHz-Frequency counter with ATmega8 on www.avr-asm-tutorial.net.

To-do

  • Figure out why it breaks if testing frequencies above 10 MHz.
  • Calibrate battery voltage measurement better.
  • Custom itoa instead sprintf.
  • Consider rewriting to assembly, basing more on the code from the fcount_m8 (see "inspired by" link above).