Pronterface Ubuntu not connecting to Prusa i3 printer

I am using Ubuntu 14.04.1 and I'm trying to get Pronterface to connect to the printer. The serial port that it defaults to is /dev/ttyACM0 I believe (could be slightly wrong, I do not have the printer with me right now to see. It is for a school project). I have my baudrate set to 250000 which is correct for Marlin which I have loaded onto the Arduino. I open Pronterface with

 sudo ./pronterface.py

When I try to connect to the printer it just gets stuck on "connecting..." and never stops. I'm not sure if it makes a difference, but right now the only thing that is connected to the board is the motors and power supply. This is for school so other members of the group are working on other things so I don't exactly have all the other parts yet.

My i3 connects at baud rate 115200

Maybe try that?

I have tried other baud rates, 250000 is correct for the Marlin firmware that I am using.

Hello,
This problem is related of baudrates. In your operating system, the python library used for the serial connection is limited to 115200 bauds. Then, you have two solutions:
* Configure the firmware of your printer with 115200 bauds, and choose 115200 bauds in pronterface
* Follow the documentation to apply a patch to the python library: [reprap.org]

I had the same issue with Linux Mint 17, which is based on Ubuntu 14.04. I use the patch, it works for me.

Edited 1 time(s). Last edit at 01/16/2015 09:58AM by kimented_.

Men, you saved my day (night, should say). I have Ubuntu 14.04 and that Patch made the magic. I started Pronterface without using SUDO, and my user is in the group alowed to comunicate by USB. Now it works fine. Thank you guys!!