Cannot install Python libraries for pHat on Pi Zero W

[C-D-Lewis]

Cannot install Python libraries for pHat on Pi Zero W

[Gadgetoid]

I'm not sure what's happened here. The issue appears to be with the smbus2 package, but glancing over the source/GitHub history suggests it hasn't changed meaningfully in a while.

It might be worth trying: sudo pip install smbus2=0.2.3 followed by sudo pip install inky to see if it works around the problem.

[Gadgetoid]

I grabbed the latest smbus2 package to inspect, and extras_require looks fine. I suspect your downloaded/extracted file was corrupted, or some other temporary issue occured. You could also try:

sudo pip --no-cache-dir install smbus2

[C-D-Lewis]

Thanks @Gadgetoid for the swift feedback. I tried the first command to little success:

pi@raspberrypi:~ $ sudo pip install smbus2=0.2.3
Exception:
Traceback (most recent call last):
  File "/usr/lib/python2.7/dist-packages/pip/basecommand.py", line 122, in main
    status = self.run(options, args)
  File "/usr/lib/python2.7/dist-packages/pip/commands/install.py", line 269, in run
    InstallRequirement.from_line(name, None))
  File "/usr/lib/python2.7/dist-packages/pip/req.py", line 173, in from_line
    return cls(req, comes_from, url=url, prereleases=prereleases)
  File "/usr/lib/python2.7/dist-packages/pip/req.py", line 71, in __init__
    req = pkg_resources.Requirement.parse(req)
  File "/usr/lib/python2.7/dist-packages/pkg_resources.py", line 2793, in parse
    reqs = list(parse_requirements(s))
  File "/usr/lib/python2.7/dist-packages/pkg_resources.py", line 2721, in parse_requirements
    "version spec")
  File "/usr/lib/python2.7/dist-packages/pkg_resources.py", line 2686, in scan_list
    raise ValueError(msg, line, "at", line[p:])
ValueError: ('Expected version spec in', 'smbus2=0.2.3', 'at', '=0.2.3')

Also

pi@raspberrypi:~ $ sudo pip --no-cache-dir install smbus2

Usage:
  pip <command> [options]

no such option: --no-cache-dir

Perhaps I need a new Python version or a cleaner environment?

[Gadgetoid]

Oof I missed an = in my command, despite trying not to miss an = in my command. Try:

sudo pip install smbus2==0.2.3

The lack of a --no-cache-dir option might suggest a very out of date smbus, worth trying a sudo apt update followed by sudo apt upgrade and then sudo pip install --upgrade pip.

Is this an old Pi setup on Raspbian Jessie?

[C-D-Lewis]

Thanks @Gadgetoid, I will re-attempt this weekend!

[C-D-Lewis]

@Gadgetoid Still little success, sadly. Here is the versions I'm using:
Hardware: Pi Zero W
Software: Raspbian GNU/Linux 8 (jessie)
Python: 2.7.9 (/usr/bin/python)
pip: pip 19.2.3 (/usr/local/bin/pip)

And yet the same problem with installing smbus persists. Is it worth trying a completely fresh image?

[C-D-Lewis]

After a fresh Buster install and over an hour and a half of compiling numpy, it finished installing successfully! However, I now have another issue (sadly!)

Python 2.7.16 (default, Apr  6 2019, 01:42:57)
[GCC 8.2.0] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import inky
>>> from inky import InkyPHAT
>>> inkyphat = InkyPHAT('yellow')
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/usr/local/lib/python2.7/dist-packages/inky/phat.py", line 27, in __init__
    v_flip=False)
  File "/usr/local/lib/python2.7/dist-packages/inky/inky.py", line 74, in __init__
    self.eeprom = eeprom.read_eeprom()
  File "/usr/local/lib/python2.7/dist-packages/inky/eeprom.py", line 103, in read_eeprom
    i2c = SMBus(1)
  File "/usr/local/lib/python2.7/dist-packages/smbus2/smbus2.py", line 279, in __init__
    self.open(bus)
  File "/usr/local/lib/python2.7/dist-packages/smbus2/smbus2.py", line 308, in open
    self.fd = os.open(filepath, os.O_RDWR)
OSError: [Errno 2] No such file or directory: '/dev/i2c-1'

I did some Googling and determined that i2c was not enabled. I followed these instructions (with the exception of using apt instead of pacman to install the I2C tools, and after a reboot I could use InkyPHAT('yellow') without the same error.

However, when trying to follow the 'set border' example in the README.md file, (which should read inkyphat.BLACK etc instead of ink.BLACK, I got this:

>>> inkyphat.set_border(inkyphat.BLACK)
>>> inkyphat.show()
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/usr/local/lib/python2.7/dist-packages/inky/inky.py", line 325, in show
    self._update(buf_a, buf_b, busy_wait=busy_wait)
  File "/usr/local/lib/python2.7/dist-packages/inky/inky.py", line 238, in _update
    self.setup()
  File "/usr/local/lib/python2.7/dist-packages/inky/inky.py", line 213, in setup
    self._spi.open(0, self.cs_pin)
IOError: [Errno 2] No such file or directory

After more Googling and using raspi-config to enable the SPI interface, I am now able to use the display! 😄

Closing this now.