After a few trials and errors, I finally got Octoprint to work with a Polarbot (vertical drawing machine)
It wasn't that hard because the brain of the polarbot use Repetier firmware (with some modifications)
For this to work, I had to change two things in repetier and penplotter (the provided host software) so they doesn't use M0 Gcode anymore (that's only after I realized there is an option in OP to bypass this GCode)
After some preferences tuning (I don't need temperature control, GCode view is messy, etc...) here I am !
I still need to fine-tune all the process to get the GCode, right now I have to :
- Optionnally, use Gimp or Photshop to split an image into severa B&W images representing the main colors
- Use Drawbot2Gcode to convert bitmaps to SVG (the generated GCode is not properly dimensionned)
- Use Inkscape to tune the SVG, combine colors, add text, etc...
- Use Penplotter to convert the SVG into a proper GCode file
- Send it/them to OP
For multicolor drawings, I use a 4 ou 10 colors pen and just switch color after each "layer"
I'm pretty pleased by the results so far
So, it's not the first time but I want to thank again @foosel for Octoprint, not only it work like a charm with (most of) 3D Printers, but it's still flexible enough to work with some other type of machine.
Next challenge : try to use it to control a CNC-mill ;D