Error running i2c example code on BeagleBone Black

[pavo]

Please see the trace below:

/usr/local/lib/python2.7/dist-packages/setuptools-3.5.1-py2.7.egg/pkg_resources.py:1031: UserWarning: /home/ubuntu/.python-eggs is writable by group/others and vulnerable to attack when used with get_resource_filename. Consider a more secure location (set with .set_extraction_path or the PYTHON_EGG_CACHE environment variable).
Traceback (most recent call last):
File "image.py", line 47, in
disp = Adafruit_SSD1306.SSD1306_128_64(rst=RST)
File "build/bdist.linux-armv7l/egg/Adafruit_SSD1306/SSD1306.py", line 239, in init
File "build/bdist.linux-armv7l/egg/Adafruit_SSD1306/SSD1306.py", line 105, in init
File "build/bdist.linux-armv7l/egg/Adafruit_GPIO/I2C.py", line 64, in get_i2c_device
File "build/bdist.linux-armv7l/egg/Adafruit_GPIO/I2C.py", line 75, in init
IOError: [Errno 2] No such file or directory

The above is having modified image.py appropriately for my display:

128x64 display with hardware I2C:

disp = Adafruit_SSD1306.SSD1306_128_64(rst=RST)

Beaglebone Black pin configuration:

RST = 'P9_12'

Note the following are only used with SPI:

DC = 'P9_15'
SPI_PORT = 1
SPI_DEVICE = 0

I hope this can help someone.

[tdicola]

It sounds like the SPI device you're using might not be enabled with a device tree overlay. Can you try running this command to show all the SPI devices?

ls /dev/spi*

Based on the device and port you should see a /dev/spidev1.0 device. If you don't see that device then you'll need to enable it with a device overlay. Check out the bottom of this page for a little more info on how to enable the SPI device: https://learn.adafruit.com/ssd1306-oled-displays-with-raspberry-pi-and-beaglebone-black/wiring

One other thing to be careful about, since it looks like you're using Ubuntu. Make sure the kernel version is 3.8.x and not a later one like 3.14.x. The later kernels don't support device tree overlays so they can't dynamically add SPI ports, etc. You can check the kernel version by runnning:

uname -r

If it's a later kernel (like 3.14) try installing the official Debian image from there as it's still using 3.8: http://beagleboard.org/latest-images