Difference between revisions of "OLA Python API"

Revision as of 10:50, 9 January 2011

Building the Python Bindings

You need the python version of protocol buffers installed.

See Building LLA but run

$ ./configure --enable-python-libs

Check where the modules are going to be installed:

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

Run the usual: make, make check, make install.

Check that the modules have been installed correctly in the $pythondir above.

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/install/dir

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

Interesting Classes

LlaClient

the main connection class

dmxBuffer

represents a list of DMX channel values

LlaClientObserver

base class to handle events

LlaPlugin

represents a Plugin

LlaDevice

represents a Device

Sending DMX

A simple example to send DMX:

from lla import *
import sys

con = LlaClient()
if con.start():
  sys.exit()

universe = 0

# create a dmxBuffer for the channel values
DMX_LEN = 512
dmx = dmxBuffer(DMX_LEN)
for i in range(0, DMX_LEN):
  dmx[i] = i

con.send_dmx(universe, dmx, DMX_LEN)

Receiving DMX

Receiving is slightly harder, we need to setup an Observer object to handle the events:

THIS ISN'T WORKING YET [simonn]

from lla import *
import sys

class Observer(LlaClientObserver):
  """ Handle the events """
  def new_dmx(self, uni, length, data):
    """ Called with new dmx buffer """
    return 0


# create a new LlaClient
con = LlaClient()

# create an observer object and register
ob = Observer()
con.set_observer(ob)

if con.start():
  sys.exit()

con.register_uni(1, LlaClient.REGISTER)

while True:
  con.fd_action(1)