OLA LED Pixels

Since March 2013, OLA contains an SPI plugin, which allows you to drive strings of LEDs pixels provided your hardware has an SPI device. Using embedded Linux platforms like the Raspberry Pi, this allows one to build Pixel strings controlable via any of the supported protocols (ArtNet, E1.31, OSC & more) for < $100.

Alternatively if you don't want network control, you can send DMX512 to the LEDs using the Python, C++ or Java client library.

Supported Hardware

On the host side, any SPI hardware supported by the Linux kernel should work correctly. By default OLA looks for devices in the form /dev/spi* . If you're using a Raspberry Pi you can save yourself a lot of time by using the pre-built images, see OLA on the Raspberry Pi for details.

On the LED pixel side the following is supported:

• LPD8806, e.g. https://www.adafruit.com/products/306
• WS2801, e.g. https://www.adafruit.com/products/738

Only the WS2801 is supported in the 0.8.27 release. Code to support LPD8806 is in the git repo and will be in 0.8.28.

Hardware Setup

TODO(someone): document this.

Software Setup

Once you have OLA running it's a matter of patching an SPI Output port to a universe and then patching the desired input port. This can be done from the OLA web UI, which runs on port 9090.

Example of an ArtNet controlled LED String

Configuration

The type of LED drivers, operating mode and DMX Start Address are configurable via RDM. Click on the RDM tab and you'll see the options.

Using RDM to set the hardware type and DMX start address

The number of LEDs and SPI speed is set using the ola-spi.conf file.

base_uid = 7a70:00000100
device_prefix = spidev
enabled = true
spidev0.0-dmx-address = 1
spidev0.0-personality = 1
spidev0.0-pixel-count = 25
spidev0.0-spi-speed = 100000
spidev0.1-dmx-address = 1
spidev0.1-personality = 2
spidev0.1-pixel-count = 25
spidev0.1-spi-speed = 100000