rm-hull/luma.led_matrix

Segmentation fault with simple example

DanielSSilva opened this issue · 7 comments

DanielSSilva commented

Hi! Let me start by stating that I'm not super familiar with Python and I'm new to using this library. I'm using this library to develop a project with the NeoPixels. I've followed the installation guide and I'm able to get the expected results, however, everytime the program finishes I have a segmentation fault.
From what I was able to understand, this library uses the ws_281x C library, which can be where the problem relies....

Type of Raspberry Pi

Tested on a Rpi3 and Zero W

Linux Kernel version

Linux raspberrypi 5.10.17-v7+ #1414 SMP Fri Apr 30 13:18:35 BST 2021 armv7l GNU/Linux

Expected behaviour

Code run without any issue

Actual behaviour

Message is successfully displayed on the LEDs, but after that I get Segmentation fault, without any further information.

Here's the sample that I'm using

from luma.led_matrix.device import neopixel
from luma.core.legacy import show_message
from luma.core.legacy.font import proportional, SPECCY_FONT #https://luma-core.readthedocs.io/en/latest/_modules/luma/core/legacy/font.html

device = neopixel(width=16, height=7)
device.contrast(50)
def main():
    msg = "Hi!"
    show_message(device, msg, y_offset=-1, fill="green", font=proportional(SPECCY_FONT), scroll_delay=0.04)    

if __name__ == "__main__":
    try:
        main()
    except KeyboardInterrupt:
        pass
thijstriemstra commented

after that I get Segmentation fault, without any further information.

Can you paste at least the seg fault message? And what python 3 version are you using? can you try a different version?

DanielSSilva commented

Can you paste at least the seg fault message?

That's the thing, the only message that I get is "Segmentation fault". There's no stack trace or anything related.

And what python 3 version are you using? can you try a different version?

I've just installed raspbian, so I'm assuming it's either 3.6 or 3.7. I'll try with another version when I get the chance. Should I try with some 3.x, or should it be with 2.x?

thijstriemstra commented

Only 3.x is supported. Check version with python --version or python3 --version.

DanielSSilva commented

Here's both the python3 version (3.7.3) as well as the segmentation fault message that I get.
What's the best way to test with other python version? I was googling and seemed to be through pyenv? What's the recommended way to achieve this?
image

thijstriemstra commented

We have seen more issues with the stock version of Python on Raspbian. If you try latest Python 3.7.x I'm pretty sure the segfault will be gone. Unfortunately I don't see an quick way to upgrade Python on Raspbian, only compile from source.

It should be pretty straightforward though, download .zip file, unpack it and

./configure
make -j4
sudo make install
/usr/local/bin/python3 --version

And then reinstall luma.led_matrix with that new Python version.

thijstriemstra commented

was googling and seemed to be through pyenv?

ps. i dont use pyenv but it might work as well.

thijstriemstra commented

If you try latest Python 3.7.x I'm pretty sure the segfault will be gone.

No feedback, closing.