SSD1327 display fails with [Errno 22] Invalid argument

[iv-med]

Raspberry Pi Zero W
Linux raspberrypi 4.14.98+ #1200 Tue Feb 12 20:11:02 GMT 2019 armv6l GNU/Linux

Traceback (most recent call last):
  File "LinuxProject4.py", line 55, in <module>
    device = ssd1327(serial)
  File "/usr/local/lib/python3.5/dist-packages/luma/oled/device/__init__.py", line 651, in __init__
    nibble_order=1, **kwargs)
  File "/usr/local/lib/python3.5/dist-packages/luma/oled/device/greyscale.py", line 36, in __init__
    self.clear()
  File "/usr/local/lib/python3.5/dist-packages/luma/core/mixin.py", line 46, in clear
    self.display(Image.new(self.mode, self.size))
  File "/usr/local/lib/python3.5/dist-packages/luma/oled/device/greyscale.py", line 118, in display
    self.data(list(buf))
  File "/usr/local/lib/python3.5/dist-packages/luma/core/device.py", line 46, in data
    self._serial_interface.data(data)
  File "/usr/local/lib/python3.5/dist-packages/luma/core/interface/serial.py", line 106, in data
    self._bus.i2c_rdwr(self._i2c_msg_write(self._addr, [self._data_mode] + data))
  File "/home/pi/.local/lib/python3.5/site-packages/smbus2/smbus2.py", line 497, in i2c_rdwr
    ioctl(self.fd, I2C_RDWR, ioctl_data)
OSError: [Errno 22] Invalid argument

[rm-hull]

Have you followed ALL the pre-requisites here: https://luma-oled.readthedocs.io/en/latest/hardware.html#i2c ?

What is the output of i2cdetect -y 1 ?

[iv-med]

Have you followed ALL the pre-requisites here: https://luma-oled.readthedocs.io/en/latest/hardware.html#i2c ?

yes

What is the output of i2cdetect -y 1 ?

$ i2cdetect -y 1
     0  1  2  3  4  5  6  7  8  9  a  b  c  d  e  f
00:          -- -- -- -- -- -- -- -- -- -- -- -- -- 
10: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 
20: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 
30: -- -- -- -- -- -- -- -- -- -- -- -- 3c -- -- -- 
40: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 
50: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 
60: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 
70: -- -- -- -- -- -- -- --                   

[rm-hull]

I'd seen that error before, and from what I remember it gets generated when a device doesn't respond on a particular address. Obviously, as you can see, there is something on 0x3C (this is the usual address for OLED displays).

What is the output of pip list | grep luma ?

Also, can you share a bit more of your code, specifically the bit where you initialize the serial device?

[iv-med]

I'd seen that error before, and from what I remember it gets generated when a device doesn't respond on a particular address. Obviously, as you can see, there is something on 0x3C (this is the usual address for OLED displays).

What is the output of pip list | grep luma ?

pi@raspberrypi: $ pip3 list | grep luma
DEPRECATION: The default format will switch to columns in the future. You can use --format=(legacy|columns) (or define a format=(legacy|columns) in your pip.conf under the [list] section) to disable this warning.
luma (0.9.6)
luma.core (1.9.0)
luma.oled (3.2.1)

Also, can you share a bit more of your code, specifically the bit where you initialize the serial device?

from luma.core.interface.serial import i2c, spi
from luma.core.render import canvas
from luma.oled.device import ssd1327

serial = i2c(port=1, address=0x3C)
device = ssd1327(serial)

[rm-hull]

When I run an SSD1306 via I2C on the latest versions of luma.core and luma.oled I don't experience any errors, but when I tried the SSD1327 I got exactly the same problem as you described.

If I downgrade to luma.core 1.8.3 (sudo pip install luma.core==1.8.3) then the SSD1327 display works as expected. I would recommend downgrading to the earlier version in the meantime, until we can get to the bottom of the issue.

I think this regression is probably caused by this commit: rm-hull/luma.core@3502326 ... @Gadgetoid - are you able to shed any light on this at all?

[iv-med]

When I run an SSD1306 via I2C on the latest versions of luma.core and luma.oled I don't experience any errors, but when I tried the SSD1327 I got exactly the same problem as you described.

If I downgrade to luma.core 1.8.3 (sudo pip install luma.core==1.8.3) then the SSD1327 display works as expected. I would recommend downgrading to the earlier version in the meantime, until we can get to the bottom of the issue.

I think this regression is probably caused by this commit: rm-hull/luma.core@3502326 ... @Gadgetoid - are you able to shed any light on this at all?

Okay, thank you, after downgrading it works.

[rm-hull]

[Will keep this open until bug is fixed]

[rm-hull]

Reading the docs for ioctl (the method call that actually fails) it seems like there is a 1024 buffer limit, so I'm betting that this is the cause of this error.

[rm-hull]

Luma.core 1.10.1 released with the fix for this issue. Use sudo pip install luma.core -U to update to latest.