No response between Octoprint connection and Prusa I3 MK3

What is the problem?

Followed the steps outlined on the Octoprint page to flash the latest Octopi onto microSD. Then setup Octoprint with printer (Prusa MK3) and my user profiles. Webcam feed appears to work fine. However, the problem arises when trying to send temperature or gcode to my MK3 using a Raspberry Pi 3B via WiFi. Octoprint will display that it is printing or that there is a connection, but when sending temperature commands to the printer, you get no response from it. Upon connecting using auto serial port and auto baud rate, the printer will respond by turning the fan on and then show that there is a connection. I've attached the log and serial files. Please let me know if I can provide any more info.

What did you already try to solve it?

Browse various forums and ask for help on r/Prusa3D

Additional information about your setup (OctoPrint version, OctoPi version, printer, firmware, octoprint.log, serial.log or output on terminal tab, ...)

OctoPrint 1.3.9 running on OctoPi 0.15.1 on a Original I3 Prusa MK3 single extruder.

octoprint.log (25.0 KB)

serial.log (2.4 KB)


Possibly related to the issue referenced below? I'm also running Firmware 3.4.1 on my MK3.

Hello @jar2261!

You may should activate the serial.log in the OctoPrint settings:

2018-11-20 21:09:41,704 - serial.log is currently not enabled, you can enable it via Settings > Serial Connection > Log communication to serial.log

Whoops, thanks for catching that. Uploaded another serial.log.

serial.log (2.4 KB)

did you come over here from reddit? either way, welcome.

haha thanks for helping me out on Reddit. Hopefully we can figure out the issue here.

Try checking Settings > Serial Connection > Firmware & Protocol > Protocol fine tuning > Wait for start on connect:

Contrary to what was observable in serial.log here, your firmware actually appears to be sending a start on reset, and having OctoPrint wait to try to talk to it until it sees that might improve chances to not catch it in a state of still booting up. I'd also try to use a fixed baudrate instead of attempting auto detection, that can also make things hiccup.

serial.log (44.2 KB)

It looks like if I'm able to connect it's only by using the AUTO options. I tried the AUTO serial port with specific baudrates and didn't have any luck connecting that way. When I was able to connect, I was still unable to send temperature commands to the printer.

Resolved via this link.

1 Like