Cant get strandtest.py to run without root

[Quad14]

Hello,
I am trying to run strandtest.py without root access as a test for a latter script. I have enable spi on the rpi 3 and set the core_freq=250. I also changed LED_PIN = 10.
I receive the following error:
python strandtest.py
Can't open /dev/mem: Permission denied
Traceback (most recent call last):
File "strandtest.py", line 102, in
strip.begin()
File "build/bdist.linux-armv7l/egg/neopixel.py", line 106, in begin
RuntimeError: ws2811_init failed with code -13 (Unable to initialize SPI)

Is there something I need to change in strandtest.py?
Thanks!

[ErikBorra]

See #257

[Quad14]

I followed (to the best of my understanding) those instructions but was still not able to get the strandtest.py to work on spi without sudo access. I should be able to use the neopixel.py ported library correct?

[Gadgetoid]

Your error appears to be with enabling SPI, rather than the normal issue with root access required for /dev/mem.

Are you still having issues?

What do you see if you: lsmod | grep spi?

[melzoghbi]

I am having the same issue on the latest Raspbian as well. i want to be able to run this without sudo.
Yes i am a member of gpio group as well.

In my case:
sudo python strandtest.py --> WORKS

python strandtest.py --> THIS DOESN'T WORK

Here is the error i get:
RuntimeError: ws2811_init failed with code -5 (mmap() failed)

@Gadgetoid : This is the output when i run lsmod command:

Thoughts?

[PandorasFox]

make sure you set the spidev.bufsiz=32768 in /boot/cmdline.txt. I recall having a similar error until I did that, when I was testing stuff.

I haven't updated my pi in a while so it's possible something broke on the latest releases, though.

[Gadgetoid]

@melzoghbi unless you've modified standtest.py to use an SPI-enabled pin, then the mmap() error is an expected outcome. You must run with sudo to supply privileged hardware access.

[Gadgetoid]

Have duplicated this for posterity over on the Python bindings: rpi-ws281x/rpi-ws281x-python#9

For all future issues/requests relating to Python please see: https://github.com/rpi-ws281x/rpi-ws281x-python/issues/