Raspberry Pi Python (Kivy) extremely slow with sudo

Question

I've been writing a Kivy graphical program on Raspberry Pi, with the KivyPie OS (Linux pre-configured for Kivy development).

For some reason, it's running extremely slow if started with sudo. Normally, running "python main.py", the program runs at about 30 cycles per second. However, if I do "sudo python main.py", it runs as slowly as 1 cycle per 5-10 seconds.

I need to use sudo to access Raspberry's GPIO. (unless I try some other way to do it, that I see people discuss).

I'm interested, though, what could be the cause of such a massive performance drop with sudo? And is it possible to work around that?

PS: Running the same program on my PC (Linux) with and without sudo doesn't seem to cause such problem. Only on Raspberry.

Answer 1

The problem is that Kivy is using an alternative config.ini file for the root user and not the one you have in ~/.kivy/config.ini.

At the top of your python file you can add the following to force it to use the egl_rpi window:

import os
os.environ['KIVY_WINDOW'] = 'egl_rpi' 

Alternatively, you can copy your ini file over to the root using:

sudo cp ~/.kivy/config.ini /root/.kivy/config.ini