No module named 'sysfs' in newest version of Adafruit_BBIO

[AKAMEDIASYSTEM]

Hello, I've been following the recent improvements to this library with interest and gratitude - thanks for all the work you've done on this!

I updated to the most recent version (via git clone) today, and now I receive this error when running a script that polls two encoders:

Traceback (most recent call last):
  File "bbb-enc.py", line 9, in <module>
    import Adafruit_BBIO.Encoder as Encoder
  File "/usr/local/lib/python3.5/dist-packages/Adafruit_BBIO-1.0.8-py3.5-linux-armv7l.egg/Adafruit_BBIO/Encoder.py", line 7, in <module>
    import sysfs
ImportError: No module named 'sysfs'

...I see that sysfs.py exists at Adafruit_BBIO/sysfs.py but I'm not sure how to point this library at that; it's probably something simple, but I have looked around online for hints all morning and not found much.

Thanks in advance for any advice you might have!

AKA

[dplanella]

Oh, wow, this hasn't even been released and folks are already testing it, excellent :)

Is this perhaps Python 3 related? I used Python 2.7 to test the module, as my app uses Adafruit_GPIO, which is not Python3-compatible.

If you hack the Encoder.py file and add this snippet before the import sysfs line, does it all work then?

import os
import sys

file_dir = os.path.dirname(__file__)
sys.path.append(file_dir)

[AKAMEDIASYSTEM]

Oh I thought I'd give it a try since there's such quick and helpful support (thanks again!)

I added the suggested lines (and had to change one instance of iteritems to items in Encoder.py) and now things seem to be working in python3.

Thanks!

AKA

[AKAMEDIASYSTEM]

Ah, one wrinkle to this solution - I now need to be root to run the script, as when I run as user debian, I see:

PermissionError: [Errno 13] Permission denied: '/sys/devices/platform/ocp/48300000.epwmss/48300180.eqep/enabled'

...which seems logical, since sysfs is doing these changes now.

I don't mind running this all as root, though I know that's not the Best Practice. Thought I should add this to the issue, though.

Thanks again!

AKA

[RobertCNelson]

@AKAMEDIASYSTEM that should have been taken care of with:

rcn-ee/repos@e30fb68

Double check that the directory has "eqep" permissions, and then that your user is part of the eqep group.

cat /etc/group | grep eqep
eqep:x:997:debian

rcn-ee/repos@1bf3004

Regards,

[dplanella]

@AKAMEDIASYSTEM thanks for the feedback. Two things:

• Would you mind pulling from my fix-sysfs-import branch? It now includes the fixes to the two issues you mentioned. If that works, I'd send a PR against upstream.
• You don't need to be root to access the eqep modules, but you need to be part of the eqep group, as you've already found out :) Great feedback again, the documentation needs to be updated to mention that.

Make sure at least your bb-customizations package is up-to-date to include the eqep permissions fix:

sudo apt update
sudo apt upgrade bb-cape-overlays bb-customizations

@RobertCNelson how is the group membership managed for the pwm and gpio groups upon the first Debian installation? Is the debian user added to these groups by default? And if so, should debian be also added to the eqep group?

[AKAMEDIASYSTEM]

Thanks! I wasn't part of eqep group, but now I think I am:

debian@beagleboat:~$ cat /etc/group | grep eqep
eqep:x:992:debian

...now, after pulling the fis-sysfs-import (and adding the four lines to Encoder.py per @dplanella advice in this thread) (and changing iteritems to items in Encoder.py), I can successfully run the script.

(Sorry for earlier response, I forgot that after adding myself to a group I had to log out and lgo back in again!)

Thanks yet again,

AKA

[AKAMEDIASYSTEM]

...confirming for @dplanella that I did indeed run

sudo apt update
sudo apt upgrade bb-cape-overlays bb-customizations

before trying the fix-sysfs-import branch...

[dplanella]

@AKAMEDIASYSTEM thanks. You shouldn't need to change anything after pulling the fix-sysfs-import branch, that was the point of creating it.

The branch already contains these two fixes (e70a7fd and 37f7204). Are you sure you pulled it correctly (and that you switched to it)?

[AKAMEDIASYSTEM]

Heh, sorry, my ineptitude strikes again ;-)

I thought that navigating to https://github.com/dplanella/adafruit-beaglebone-io-python/tree/fix-sysfs-import and then using git clone on the HTTPS link there would get me the correct branch, but it does not. If I instead wget the ZIP file and install from there, you're right, no alterations are necessary.

Thanks!

AKA

[dplanella]

No worries, you were nearly there. After cloning, you would have just needed to switch to the branch. But the zip file works well too, I'll submit a PR now. Thanks for confirming it works!

[pdp7]

@dplanella @AKAMEDIASYSTEM I've merged #212

[pdp7]

FYI: I have created a new Release 1.0.9, and it has been published on PyPI