Actually my idea was to use Marlin to feed the torch voltage value so that it can be accounted for in the motion planner. I think that it can be used the same way that the bilinear bed leveling works, but instead of recalling values from the bed map from the memory, you’ll read voltage values in real time from the torch. This way you could adjust the height in order to compensate for warpage, but you could also plan corners and other special spots, because Marlin knows what path will be next so you could have some flags on specific spots, with various possibilities of adjustments. It would be a fully integrated solution, much better than any THC I could think of.
I think that the only thing needed here is some kind of voltage divider + some kind of filtering, in order to convert the high voltages from the plasma to lower ones, usable with the ADC of the Arduino. Then it’s just a matter of tweaking Marlin, which, according to Marlin’s guys, shouldn’t be very hard to do. They were opened to work on that, provided I could get them information about how the voltage divided would work specifically IRL, but unfortunately I don’t really know how to build the voltage divider. It’s not very easy to do at my little electronics level, you can’t just use two resistances and call it a day, there’s high frequencies involved… I’m not very comfortable experimenting since those power levels can be quite dangerous when you’re not sure about what you’re doing. So I just hope someone who actually knows that kind of electronics will jump in and come up with a solution.