Strange characters in response when connecting

What is the problem?
When I try to connect to my Monoprice Maker Ultimate 2 via usb from my octopi the connection eventually fails with no response from the printer. After trying the Monoprice/Malyan connection fix I started seeing a response when connecting in the console, but it is a lot of gibberish characters. It happens at every baud rate, and the response is longer at higher baud rates.

What did you already try to solve it?
I tried using the Malyan/Monoprice double connect plugin. I have tried increasing the timeouts.

Logs (octoprint.log, serial.log or output on terminal tab, browser error console ...)
Image attached to ensure characters render correctly

Additional information about your setup (OctoPrint version, OctoPi version, printer, firmware, browser, operating system, ...)
Browser is chrome on windows, up to date version of octoprint and octopi on 3B

Hi @Jon_Carroll!

You may try another baud rate.


I get similar gibberish back in the Recv: line at all baud rates (I tried all the presets), the content and length just varies slightly with the different baud rates.

Oh, reading here it looks like the printer board has a parity problem which totally matches the garbage you're seeing.

Basically, if OctoPrint thinks the configuration is 115200, 8N1 (the middle N there means "no parity bit") and the printer board is set for 115200, 8O1 (odd parity bit) then...

If it were me, I think I'd look into adjusting the firmware so that it has no parity (if this is indeed what's going on). That said, if you added the Malyan plugin and it won't connect then it doesn't seem like it's working. You might want to make sure that the plugin is enabled.