Knowledge Base

The Asus Tinker Board contains two I²C buses on the 40-pin GPIO header named I2C1 and I2C4, as shown in the image below. I2C1 uses pin 3 for SDA and 5 for SCL. I2C4 uses pin 27 for SDA and 28 for SCL.

This page details how to set up I²C support for the I2C1 bus, which is used by most Raspberry Pi compatible hats and expansion boards, including those from AB Electronics UK.

Step 1: Download the latest TinkerOS Debian image for your Tinker Board and burn it to your SD Card following the instructions on http://elinux.org/RPi_Easy_SD_Card_Setup

Step 2: Next, you need to update your Tinker Board to ensure all the latest packages are installed:

sudo apt-get update
sudo apt-get upgrade

Step 3 a: Once you have updated your Tinker Board, run the following command to install the Python smbus and dev libraries and the i2c-tools packages:

sudo apt-get install python3-smbus python3-dev i2c-tools

Step 4: Edit the /boot/config.txt file using nano or your preferred text editor:

sudo nano /boot/config.txt

Uncomment the line "intf:i2c1=on" as shown in the screenshot below, and save the file. To use the I2C4 bus, uncomment the "intf:i2c4=on" line changing "off" to "on".

Step 5: To avoid needing to run the I²C tools at root, add the 'linaro' user to the "i2c" group:

sudo adduser linaro i2c

Step 6: Next, reboot the Tinker Board:

sudo reboot

When your Tinker Board has rebooted, you will now have I²C and SMBus Python support.

You can find available I²C devices using the following command.

sudo i2cdetect -y 1

A grid of I²C addresses will be displayed with available devices shown by their address number.

To learn more about I²C and how to use it, read our tutorial series Introducing I2C.