How to set up i²c in Raspbian on the Raspberry Pi

 

First we need to update our package lists.

sudo apt-get update

Then we install smbus

sudo apt-get install python-smbus

install smbus for i2c


y to confirm

smbus installed

This installed i2c-tools as well, which we’ll use a little later to locate i2c devices on the system.

How to Enable i2c in Raspbian

Then we need to make a tweak to a couple of configuration file to enable i2c in raspbian.

To enable i2c in raspbian…

sudo nano /etc/modprobe.d/raspi-blacklist.conf

…and comment out line 3 (the one with i2c in) by inserting a # at the start of the line…
ctrl+o save
<ENTER> confirm filename
ctrl+x exit

commented out the i2c line (3)

Then…
sudo nano /etc/modules
you need to add…
i2c-dev on the last line

Add i2c-dev on last line

ctrl+o save
<ENTER> confirm filename
ctrl+x exit

Now we need to reboot to activate the new settings. You could do any necessary wiring while the Pi is powered down. (Do disconnect the power after shutting down) :)

sudo reboot to reboot, or sudo halt to shut down.

 Posted by at 12:42 pm

  2 Responses to “How to set up i²c in Raspbian on the Raspberry Pi”

  1. […] Make sure that you have the I2C drivers enabled on your SD card. If not, follow this post by Raspi.TV […]

  2. For the benefit of any future readers – I believe (at least part of) these instructions will no longer work properly with latest versions of Raspbian, as they now use a DeviceTree kernel by default.
    Happily, I2C can be enabled / disabled using raspi-config

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