Frequency Generator
January 2019
The aim of this project was to make my own variable square wave generator. A good arbitrary frequency generator is one of the few bits of kit I've never got around to getting for my lab and bodging up my own bread board oscillating circuit whenever a prototype requires a CLK was less time I could be experimenting with the project itself. In the end I settled on the relatively low frequency of 20Hz to 200kHz. With the plentiful amount of of unprogrammed ATmega328p microcontrollers I have laying around and having a reasonable clock speed for my frequency range that was the microcontroller I chose.
The hardware:
LM7805 voltage regulator
2x 10µf electrolytic capacitors
ATmega 328p
16MHz quartz crystal
2x 22pf ceramic capacitors
4027 JK Flip Flop
10k potentiometer
The programming was relatively simple reading the voltage level of the voltage divider, and mapping the voltage read to a delay. The enclosure was made in fusion and printed in PETG.
The finished frequency generator is no replacement for a bought one and it's duty cycle falls noticeably below 50% at higher frequencies. For use in prototyping projects it should be more than enough.
