How to install SMBus i2c module for Python 3

SMBus module worked well with Python 2, but not 3. SMBus is required to program i2c devices connected to Pi GPIO i2c pins such as the Raspy Juice servo controller.

Update:

As of the latest version of Raspbian 4.1.6 you could simply run:

sudo apt-get update

sudo apt-get install python3-smbus

done!

If you are not which Raspbian you are runing, run:

uname -a

You will get something along the lines of:

Linux raspberrypi 4.1.6-v7+ #810 SMP PREEMPT Tue Aug 18 15:32:12 BST 2015 armv7l GNU/Lin

Older versions:
Here are the steps to install it:

sudo -i
apt-get install python3-dev
apt-get install libi2c-dev
cd /tmp
wget http://ftp.de.debian.org/debian/pool/main/i/i2c-tools/i2c-tools_3.1.0.orig.tar.bz2 # download Python 2 source
tar xavf i2c-tools_3.1.0.orig.tar.bz2
cd i2c-tools-3.1.0/py-smbus
mv smbusmodule.c smbusmodule.c.orig # backup
wget https://gist.githubusercontent.com/sebastianludwig/c648a9e06c0dc2264fbd/raw/2b74f9e72bbdffe298ce02214be8ea1c20aa290f/smbusmodule.c # download patched (Python 3) source
python3 setup.py build
python3 setup.py install
exit

The next step is to enable i2c via raspi-config: sudo raspi-config , select advance menu, select i2c, then enable it.

You can now try it in your Python 3 code to control your Raspy Juice or a similar device, like this:

import smbus as smbus
import time

bus = smbus.SMBus(1)


for i in range(1000, 2000, 100):
  bus.write_word_data(0x48, 1, i)
  time.sleep(1)

bus.write_word_data(0x48, 1, 1000)

Tags: i2csmbus