The SI5351 is an i2c programmable any frequency clock generator. The chip can generate up to 8 non-integer-related frequencies from 8 kHz to 160 MHz depending on the model. For the ham radio home brewer, such a chip can be programmed as a VFO easily. All you need is the right code for the microcontroller, usually, it’s an Arduino Nano, however, amateurs have also used ATMEGA328p for the popular uSDX Project.
Here’s the Top 5 Codes For SI5351 (Remember, this is only the software)
- uBITX v6 from VU2ESE (Ashhar Farhan) https://github.com/afarhan/ubitxv6
- Easy Bitx Code from VU3GAO https://github.com/saqks-ahm/easybitx
- uSDX https://github.com/KD9PDP/uSDX-x
- QCX-SSB https://github.com/threeme3/QCX-SSB
- Bitx 40 Code https://github.com/afarhan/bitx40
All these codes can serve as an effective boilerplate for you to start tinkering with SI5251. These codes are picked up due to immense popularity within the amateur radio community. Let us know if we missed out on any popular codebase.
Edit:
I found this amazing Universal Vfo Controller for Atmega328 Si5351 by VK3KN – Paul. I missed this out previously!
https://vk3hn.wordpress.com/2021/09/30/universal-vfo-controller-atmega328-si5351
You can find the code in Paul’s Github Repo https://github.com/prt459/Arduino_si5351_VFO_Controller_Keyer
