I've used an open source, 4-channel PWM dew heater called Arduheater for a few years.
His original post on this project was back in 2017
on Stargazers lounge. Of all the opensource ones out there, this one is quite complete and well documented and even has PCB files to have them produced, which I did. The author JBrazio, has
Arduino source code
, and the
Windows GUI program
in C#. If anyone could add support to this to indi I would be forever grateful, and in your debt. I could ditch windows altogether! I have a few blank PCB's left over and I'd be happy to provide one, heck, I'd even build you a complete one.