sudo needed to run

[zeesh1979]

Hi, I am using RPI3 and added pi to gpio and kmem groups but still i get permission denied error when running the script. running with sudo works

Can't open /dev/mem: Permission denied Traceback (most recent call last): File "rgb1.py", line 84, in strip.begin() File "/usr/local/lib/python3.5/dist-packages/rpi_ws281x/rpi_ws281x.py", line 131, in begin raise RuntimeError('ws2811_init failed with code {0} ({1})'.format(resp, str_resp)) RuntimeError: ws2811_init failed with code -5 (mmap() failed) Segmentation fault

[Zoraiyo]

Hi zeesh1979,

I read somewhere in the past, that "sudo" is required to access the gpio/PWM. Sadly I don't now where I read that. I run my script with sudo too.

Best regards

[Rapti]

I'm having a similar problem although the error message is different. Using a Raspberry Pi 4B with Arch Linux ARM.

$ python monitor_server.py 
Failed to create mailbox device
: Operation not permitted
Traceback (most recent call last):
  File "/home/openhab/LED/monitor_server.py", line 160, in <module>
    strip.begin()
  File "/usr/lib/python3.9/site-packages/rpi_ws281x/rpi_ws281x.py", line 131, in begin
    raise RuntimeError('ws2811_init failed with code {0} ({1})'.format(resp, str_resp))
RuntimeError: ws2811_init failed with code -9 (Failed to create mailbox device)
Speicherzugriffsfehler (Speicherabzug geschrieben)

Running the script as root works, but I'd very much like to avoid that for obvious reasons. Is there any group I can add the user to to fix this? Being a member of gpio does the trick with other libraries using GPIO pins, but it doesn't seem to be enough in this case. I couldn't find anything about this on the internet.

[MainzerKaiser]

Did anybody find a solution for that? I get a similar error: Can't open /dev/mem: Keine Berechtigung Traceback (most recent call last): File "/home/pi/PycharmProjects/LEDStrip/main.py", line 25, in LEDStartfunct self.LEDStart() File "/home/pi/PycharmProjects/LEDStrip/LEDStart.py", line 101, in LEDStart strip.begin() File "/home/pi/PycharmProjects/LEDStrip/venv/lib/python3.7/site-packages/rpi_ws281x/rpi_ws281x.py", line 131, in begin raise RuntimeError('ws2811_init failed with code {0} ({1})'.format(resp, str_resp)) RuntimeError: ws2811_init failed with code -5 (mmap() failed)

I simply would like to initiate the LEDstart function from another program wihout executing a command string having sudo in it.

[ConnorDY]

I'm having the same problem that @Rapti described. I'm also using this with a Raspberry Pi 4B running Arch Linux ARM.

[sdparkes66]

Seeing same thing here PiZero 2 w

Script runs with SUDO.

RuntimeError: ws2811_init failed with code -9 (Failed to create mailbox device)
swig/python detected a memory leak of type 'ws2811_t *', no destructor found.
(venv) ******@PiZero1:~/Python/LEDring $ cat /proc/cpuinfo | grep Revision
Revision        : 902120

[zeesh1979]

no admin responding, i am closing it

[Gadgetoid]

This library is just a Python wrapper around https://github.com/jgarff/rpi_ws281x/

sudo is required.

[sdparkes66]

Good to know and now understand, thanks