Python API

OLA is distributed with a Python API. This makes it easy to quickly prototype new DMX512 generators.

Installation

If you’re installing from source you need to pass --enable-python-libs when running configure. i.e.

$ ./configure --enable-python-libs

Once the configure script completes, you can check where the Python modules are going to be installed by running:

$ grep ^pythondir config.log
pythondir='/Library/Python/2.5/site-packages'

After running make and make install, check that the modules have been correctly installed into $pythondir.

Finally check that $pythondir appears in sys.path:

$ python -c "import sys; print sys.path"

If it doesn’t add it to $PYTHONPATH:

$ export PYTHONPATH=$PYTHONPATH:/path/to/your/pythondir

You probably want to put this line in your shell .rc file.

Sending DMX

A simple example to send one frame of DMX data:

import array
from ola.ClientWrapper import ClientWrapper

def DmxSent(state):
  wrapper.Stop()

universe = 1
data = array.array('B', [10, 50, 255])
wrapper = ClientWrapper()
client = wrapper.Client()
client.SendDmx(universe, data, DmxSent)
wrapper.Run()

Sending Multiple Frames

import array
from ola.ClientWrapper import ClientWrapper

wrapper = None
loop_count = 0
TICK_INTERVAL = 100  # in ms

def DmxSent(state):
  if not state.Succeeded():
    wrapper.Stop()

def SendDMXFrame():
  # schdule a function call in 100ms
  # we do this first in case the frame computation takes a long time.
  wrapper.AddEvent(TICK_INTERVAL, SendDMXFrame)

  # compute frame here
  data = array.array('B')
  global loop_count
  data.append(loop_count % 255)
  loop_count += 1

  # send
  wrapper.Client().SendDmx(1, data, DmxSent)

wrapper = ClientWrapper()
wrapper.AddEvent(TICK_INTERVAL, SendDMXFrame)
wrapper.Run()

Receiving DMX

Here is some code to receive DMX on universe 1.

from ola.ClientWrapper import ClientWrapper

def NewData(data):
  print data

universe = 1

wrapper = ClientWrapper()
client = wrapper.Client()
client.RegisterUniverse(universe, client.REGISTER, NewData)
wrapper.Run()