Python usage

OLED displays can be driven with python using the varous implementations in the luma.oled.device package. There are several device classes available and usage is very simple if you have ever used Pillow or PIL.

First, import and initialise the device:

from luma.core.serial import i2c, spi
from luma.core.render import canvas
from luma.oled.device import ssd1306, ssd1325, ssd1331, sh1106

# rev.1 users set port=0
# substitute spi(device=0, port=0) below if using that interface
serial = i2c(port=1, address=0x3C)

# substitute ssd1331(...) or sh1106(...) below if using that device
device = ssd1306(serial)

The display device should now be configured for use. The specific luma.oled.device.ssd1306, luma.oled.device.ssd1325, luma.oled.device.ssd1331, or luma.oled.device.sh1106, classes all expose a display() method which takes an image with attributes consistent with the capabilities of the device. However, for most cases, for drawing text and graphics primitives, the canvas class should be used as follows:

with canvas(device) as draw:
    draw.rectangle(device.bounding_box, outline="white", fill="black")
    draw.text((30, 40), "Hello World", fill="white")

The luma.core.render.canvas class automatically creates an PIL.ImageDraw object of the correct dimensions and bit depth suitable for the device, so you may then call the usual Pillow methods to draw onto the canvas.

As soon as the with scope is ended, the resultant image is automatically flushed to the device’s display memory and the PIL.ImageDraw object is garbage collected.

Color Model

Any of the standard PIL.ImageColor color formats may be used, but since the SSD1306 and SH1106 OLEDs are monochrome, only the HTML color names "black" and "white" values should really be used; in fact, by default, any value other than black is treated as white. The luma.core.canvas object does have a dither flag which if set to True, will convert color drawings to a dithered monochrome effect (see the 3d_box.py example, below).

with canvas(device, dither=True) as draw:
    draw.rectangle((10, 10, 30, 30), outline="white", fill="red")

There is no such constraint on the SSD1331 OLED which features 16-bit RGB colors: 24-bit RGB images are downsized to 16-bit using a 565 scheme.

The SSD1325 OLED supports 16 greyscale graduations: 24-bit RGB images are downsized to 4-bit using a Luma conversion which is approximately calculated as follows:

Y’=0.299R’+0.587G’+0.114B’

Landscape / Portrait Orientation

By default the display will be oriented in landscape mode (128x64 pixels for the SSD1306, for example). Should you have an application that requires the display to be mounted in a portrait aspect, then add a rotate=N parameter when creating the device:

from luma.core.serial import i2c
from luma.core.render import canvas
from luma.oled.device import ssd1306, ssd1325, ssd1331, sh1106

serial = i2c(port=1, address=0x3C)
device = ssd1306(serial, rotate=1)

# Box and text rendered in portrait mode
with canvas(device) as draw:
    draw.rectangle(device.bounding_box, outline="white", fill="black")
    draw.text((10, 40), "Hello World", fill="white")

N should be a value of 0, 1, 2 or 3 only, where 0 is no rotation, 1 is rotate 90° clockwise, 2 is 180° rotation and 3 represents 270° rotation.

The device.size, device.width and device.height properties reflect the rotated dimensions rather than the physical dimensions.

Examples

After installing the library, head over to the luma.examples repository, and try running the following examples (and more):

Example	Description
3d_box.py	Rotating 3D box wireframe & color dithering
bounce.py	Display a bouncing ball animation and frames per second
carousel.py	Showcase viewport and hotspot functionality
clock.py	An analog clockface with date & time
colors.py	Color rendering demo
crawl.py	A vertical scrolling demo, which should be familiar
demo.py	Use misc draw commands to create a simple image
game_of_life.py	Conway’s game of life
grayscale.py	Greyscale rendering demo
invaders.py	Space Invaders demo
maze.py	Maze generator
perfloop.py	Simple benchmarking utility to measure performance
pi_logo.py	Display the Raspberry Pi logo (loads image as .png)
savepoint.py	Example of savepoint/restore functionality
starfield.py	3D starfield simulation
sys_info.py	Display basic system information
terminal.py	Simple println capabilities
tv_snow.py	Example image-blitting
tweet_scroll.py	Using Twitter’s Streaming API to display scrolling notifications
welcome.py	Unicode font rendering & scrolling

Further details of how to run the examples is shown in the example repo’s README.

Emulators

There are various display emulators available for running code against, for debugging and screen capture functionality:

• The luma.core.emulator.capture device will persist a numbered PNG file to disk every time its display method is called.
• The luma.core.emulator.gifanim device will record every image when its display method is called, and on program exit (or Ctrl-C), will assemble the images into an animated GIF.
• The luma.core.emulator.pygame device uses the pygame library to render the displayed image to a pygame display surface.

Invoke the demos with:

$ python examples/clock.py -d capture

or:

$ python examples/clock.py -d pygame

Note

Pygame is required to use any of the emulated devices, but it is NOT installed as a dependency by default, and so must be manually installed before using any of these emulation devices.