Laos CUPS driver: how to engrave?
I have a Chinese EUR500 laser cutter, on which I promptly managed to blow up the controller IC. I'm not one to go whine about warrantee, especially not when the IC only is compatible with the... less well written... Moshidraw 'software'. I decided to go another route and replace the chip with an ATMega, and make it compatible with Laos' simple drawing command protocol. That way, I could re-use the CUPS driver of your lovely project, many thanks for that.
Anyway, curring works like a charm at the moment, just print in Inkscape and a minute later you have whatever you want sitting on the bed of the laser cutter. Engraving is giving me problems, however. Somehow, I can't get the engraving commands out of the CUPS driver: if I copy an image into it and print it over the laser cutter driver, I end up with an empty lgc file (apart from the initial commands and the header and footer comments) to send to the cutter. Strangely, printing to a .ps file from Inkscape and then running pstoedit over the file manually does give me a file-full of engraving commands.
Any idea what could be happening here? Do I need to do something special with the image before the CUPS driver accepts it as a thing to engrave