Lightburn cannot connect to my RUMBA board running Marlin 2.0.9.2. It gets stuck on Waiting for Connection. I made the Device profile manually and selected Marlin as the connection type. Right clicking on Devices does not connect (just prints a new “Waiting for Connection” prompt in the console). Lightburn seems to continually send G0 but doesn’t get a response (that prints in the LB console, at least). Resetting the board in this state doesn’t change anything. Neither does unplugging and replugging the board.
Turning on “Enable DTR” in the Device settings pane doesn’t do anything.
Yet the Arduino app happily refreshes the board, and when I use the Mac Serial (“Decisive Tactics” third party) app I can successfully connect and manually send/receive commands. G0 works, as does M115 (I don’t have the board connected to anything else yet so these seemed like the only useful commands to test).
If I refresh the board and leave it powered up, then quit Arduino and start Lightburn, sometimes it partially connects (but doesn’t seem to hold the connection).
Thanks for the hint. LB (1.0.6 on Mac) defaulted to 250000 baud (no idea why). I had to make sure that “Enable DTR Signal” under tools->Device Settings is off, and the baud rate changed in that dialog to 115.2K, then restart Lightburn. Now it works reliably.