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This is a library for the SSD1306 OLED Display written in Ruby. It was inspired by Adafruit's libraries written in Python and C. Much of the original logic was simply ported from their Python library, but in addition this Ruby library provides additional functionality such as print and println helpers. The library also features simple image parsing.


Add this line to your application's Gemfile:

gem 'SSD1306'

And then execute:

$ bundle

Or install it yourself as:

$ gem install SSD1306


Using the library is simple. To start with, require the library and initialize the display:

require 'SSD1306'
disp =

The default options are suitable for the Raspberry Pi and a 128x64 display. These can be overridden by specifying values like so:

disp = :i2c, path: '/dev/i2c-1', address: 0x3C, width: 128, height: 64)

Writing text on the display is simple:

disp.println "This is my IP Address:"
disp.println "" # The same as disp.print "\n"
disp.font_size = 2
disp.println ip_address

You can also display monochrome images:

include Magick  # RMagick is a dependency
image ="path/to/my/image.png").first # returns an array

disp.image(image) # Pass in an RMagick image object

The display can also be easily cleared:


# Or more simply:

Check out the source code for additional information.


  • Currently only 1, 2, and 4 work as font sizes. In the meantime, to use other fonts or font sizes, I recommend using RMagick's annotate feature and passing in an image.
  • Implement SPI. Only I2C is currently supported. (For v1.0)


After checking out the repo, run bundle install to install dependencies. Then, run rake test to run the tests. Run bundle exec SSD1306 to use the gem in this directory, ignoring other installed copies of this gem.

To install this gem onto your local machine, run bundle exec rake install. To release a new version, update the version number in version.rb, and then run bundle exec rake release, which will create a git tag for the version, push git commits and tags, and push the .gem file to


Bug reports and pull requests are welcome on GitHub at


This library is inspired by the Adafruit SSD1306 Python library, available here:


Copyright (c) 2016 Xavier Bick under the MIT License. See the LICENSE file for details.