Summary:
I have recently built an Anycubic Kossel Linear Plus delta - it works 100% with Repetier-Host, but fails to connect with Pronterface.
History:
When I first got this machine it showed up on my Linux system as /dev/ttyACM0, and Pronterface had no difficulty connecting to it. Unfortunately the version of Marlin that was pre-loaded on the board was useless at auto-calibration, so I upgraded to Marlin 1.1.9 and worked successfully through the calibration procedure.
Current situation:
Now the printer works perfectly when connected to Repetier-Host, so clearly the link between the Trigorilla board and Linux is good. When I try to connect using Pronterface all I see in the console is "connecting..." followed by "SENT: M105" (report temperatures) repeating every few seconds (with debug on). Pronterface doesn't make the connection and appears to be waiting for a response from the printer. On very rare occasions the printer will make the connection and from that point on everything is normal - but this is VERY rare.
After the Marlin upgrade the printer now appears as /dev/ttyUSB0, but that may just be a red herring as far as this problem is concerned. Note that I'm using the same connecting lead and the same USB port to connect to the one Trigorilla board.
I have tried to look at the comms setup in each program and they appear to be identical, as far as I can tell; there aren't many options to play with apart from the baud rate. The baud rate on the board and in both programs is 250000 - originally the baud rate of the Trigorilla board when purchased 115200, but I'm reluctant to down-grade the Marlin code while it's working OK on Repetier-Host.
I also have a Prusa i3 clone that's using a RAMPS board that I've also upgraded to Marlin 1.1.9, and that is working perfectly with both programs at the same baud rate.
Can anyone give me any clues about what to look at next?