I’ve recently upgraded my K8400 to run a pair of e3d V6 print heads, and they went well. They’re printing away really nicely. What I want to do next is be able to switch the e3d fans on and off (the permanent cooling fans) so when a print is finished, I don’t have to listen to them bellowing away.
I had the LED controller but removed it which got me to thinking that I could use the programmable pins on the main board, but I don’t really know what I’m doing after that.
I am happy to use a signal from one of the pins (PG1?) to drive a power expander to switch the fans - this way I don’t put any extra load on the main board.
Does anyone know if I’m choosing the right pin, and do I need to make any changes to marlin as well?