Arch with Linux 5.12 up, does not seem to communicate properly at 250000 baud

JanErik

Running 5.12.4-arch1-2 from 15.5, Repetier-Host 2.2.2 does not seem to communicate properly at 250000 baud with my 3D printer. It connects with "No start signal detected - forcing start" and "1 Command waiting" and does not show any temperatures as it normally would.Other USB-serial devices such as Arduinos work fine at 9600 baud. Both CDC_ACM as the printer (/dev/ttyACMx) and ch341 (/dev/ttyUSBx). But, tried to make an Arduino sketch with 250000 baud serial communication and I get this:

Error while setting serial port parameters: 250,000 N 8 1

Tested 3D printer with a LUbuntu 18.04 laptop and that works fine so there is nothing wrong with the printer.

Repetier

Linux serial for mono only supports ANSI baud rates and 250000 is none of this. To overcome this we have put a small C++ software SetBaudrate in the same folder as the host. Please check if you can call it manually or if it is missing a library on your linux. Would explain that it fails. If it fails there is also the sourcecode SetBaudrate.cpp contained, so compile it:
g++ SetBaudrate.cpp -o SetBaudrate

configureFirst would do so already but only if g++ is installed.

JanErik

That seems to resolve the issue for now, I set the baudrate after connecting in RepetierHost but it does take some ten seconds before it gains communication.

Repetier

Actually host will call SetBaudrate on it's own when it sees a non ansi baud rate. When you start from console do you see a error message when it tries this?

JanErik

Nope, I do remember seeing it before.

[jskata@Samsung ~]$ repetierHost
[jskata@Samsung ~]$
(mono:697): Gtk-WARNING **: 11:37:31.302: Unable to locate theme engine in modul
e_path: "adwaita",
libpng warning: iCCP: known incorrect sRGB profile

[jskata@Samsung ~]$ RepetierHost/SetBaudrate /dev/ttyACM0 250000
actual baud: 250000

Repetier

Yes, that is how we do it. Just connect to same serial and switch baud rate. And call seems to work. So might be a timing issue being called too quickly maybe so it does not work. After all if I understand you when you call it a bit later it starts working, right? In that case you might want to rename SetBaudrate and replace it with a script that does sleep 1 and then calls the correct command.