Over the weekend (1/28/17) I upgraded from Raspian and Openhab2 Snapshot to Openhabian and the first release of Openhab2.
Unfortunately, when I booted into Openhabian, I can’t seem to get the I2C bus to work correctly. I have followed the standard config of installing i2c-tools and making sure nothing is blacklisted. I ran Raspi-config to enable I2C on the device. I even tried giving the user Openhab complete authority in the Sudoers file.
However, when I run i2cdetect, I have no ID being sent back from the 23017 chip. The voltages all look good on the chip but it doesn’t seem to want to respond.
Is there something that has been removed from the original Raspian that would cripple the I2C bus?
Good to hear you have this working. The procedure I listed above worked for me at the time, unfortunately I forgot to include the versions, maybe the version you are using behaves slightly different. I’m not using a Raspi anymore, otherwise I’d check and include more details here. Either way, between what worked for me before and what you figured out in your version [openHAB 2.5.0~S1558-1 (Build #1558)] others may be able to get this working as well.
For anyone looking to enable i2c on modern OpenHABian (1.7.3) on raspberry pi 4 (probably same on 3 though). @edmund-troche’s solution still works, but now you only need to do two things.
add the following two lines to /etc/modules
i2c-dev
i2c-bcm2835 # this is the same for raspi 3 & 4.
add/uncomment these two lines in /boot/config.txt
dtparam=i1c_arm=on
dtparam=i2c1=on