nicosingh/rpi-i2cdisplay repository overview

⁠About

Docker image of Raspbian prepared to display messages in a 1602A screen using I2C bus.

⁠Preparing image execution

Before anything, we have to enable I2C interface in our raspberry pi. This can be done in raspy-config > Advanced Settings > I2C Enable/Disable > choose "yes".

Then, we have to know two values related to our LCD screen:

1. I2C Bus: "1" (for original raspberry pi) or "2" (for raspberry pi revision 2 or 3)
2. I2C Address: I2C connected device address can be discovered with the following command: i2cdetect -y 1.

Finally, we have to create a folder in our host filesystem to host two files: row1.txt and row2.txt, to host the plaintext messages to be displayed in our screen. Remember this path name.

⁠How to use this Docker image?

Having I2C interface enabled in our raspberry pi and knowing I2C bus and address, we can execute our Docker image issuing something like:

docker run -d --restart=always --privileged -e I2C_BUS=1 -e I2C_ADDRESS=20 -v /tmp/lcdvolume:/tmp/textRows nicosingh/rpi-i2cdisplay

Where:

-d (optional): Is recommended to run this container as a daemon

--restart=always (optional): Is recommended to restart our container when it goes down (ie. by a system reboot).

--privileged (required): Is required to use GPIO ports and Python SMBUS libraries in our image.

-e I2C_BUS (required): Is our LCD I2C Bus number (1 or 2).

-e I2C_ADDRESS (required): Is our LCD I2C Address.

-v my_lcd_text:/tmp/textRows (optional): Means we are mounting our local folder my_lcd_text into our container. This folder is in our docker host and contains row1.txt and row2.txt files.

⁠Source Code

Gitlab: rpi-i2cdisplay⁠