:orphan:

============================

python-openzwave hello_world

============================

Here is the hello_world example for the python-openzwave API. In this

tutorial we will implement a simple sniffer. The full code is available

in the examples directory : hello_world.py.

Some theory

===========

OpenZwave uses the mechanism of notifications to manage events network.

When the driver is ready, the node is added, a value is modified, ... openzwave

generates a notification you must catch with a callback function.

Python-openzwave API catch the notification and send a louie signal.

Some words about python-louie : it's a simple mechanism where a dispatcher

send a signal on a channel, and clients connect to him.

Here is the way a sender dispatch a signal :

.. code-block:: python

dispatcher.send(self.SIGNAL_NODE, **{'network': self, 'node':self.nodes[args['nodeId']]})

Here is the way a client connect to a channel :

.. code-block:: python

dispatcher.connect(louie_node_update, ZWaveNetwork.SIGNAL_NODE)

The first argument is a call back function :

.. code-block:: python

def louie_node_update(network, node):

print('Louie signal : Node update : %s.' % node)

It receives as parameters the ones populate by the sender : the network ans a node in ths case.

The callback must set its parameter names as the same as the sender.

Hello from ZWave

================

The import clauses :

.. code-block:: python

import openzwave

from openzwave.node import ZWaveNode

from openzwave.value import ZWaveValue

from openzwave.scene import ZWaveScene

from openzwave.controller import ZWaveController

from openzwave.network import ZWaveNetwork

from openzwave.option import ZWaveOption

import time

from louie import dispatcher, All

First thing to do is to defined some options for the manager :

.. code-block:: python

options = ZWaveOption(device, config_path="../openzwave/config", user_path=".", cmd_line="")

options.set_log_file("OZW_Log.log")

options.set_append_log_file(False)

options.set_console_output(False)

options.set_save_log_level('Debug')

options.set_logging(True)

network = None

We also defined a network object, we will populate it later.

To use this options, you must lock them. No further modification could be done on them.

.. code-block:: python

options.lock()

We can now create the network :

.. code-block:: python

network = ZWaveNetwork(options, autostart=False)

The signals listeners

=====================

We will now create some connection to the louie dispatcher. We will then to 3

main signals, they will notify us about the state of the network :

.. code-block:: python

dispatcher.connect(louie_network_started, ZWaveNetwork.SIGNAL_NETWORK_STARTED)

dispatcher.connect(louie_network_failed, ZWaveNetwork.SIGNAL_NETWORK_FAILED)

dispatcher.connect(louie_network_ready, ZWaveNetwork.SIGNAL_NETWORK_READY)

To do that we use 3 callback functions :

When the driver is ready, we simply print some options on the screen :

.. code-block:: python

def louie_network_started(network):

print("Hello from network : I'm started : homeid %0.8x - %d nodes were found." % (network.home_id, network.nodes_count))

When the driver fails, we reports the error to screen :

.. code-block:: python

def louie_network_failed(network):

print("Hello from network : can't load :(.")

This an important event. It means that all nodes have been queried on the network.

You can now use the network object pass in parameter to query nodes. To do that we connect

to some louie signals. It also sleep during 5 minutes. After that, the scripts

will continue and the network will be stopped.

.. code-block:: python

def louie_network_ready(network):

print("Hello from network : I'm ready : %d nodes were found." % network.nodes_count)

print("Hello from network : my controller is : %s" % network.controller)

dispatcher.connect(louie_node_update, ZWaveNetwork.SIGNAL_NODE)

dispatcher.connect(louie_value_update, ZWaveNetwork.SIGNAL_VALUE)

When a node is updated, added, removed, ...

.. code-block:: python

def louie_node_update(network, node):

print('Hello from node : %s.' % node)

When a value is updated, added, removed, ...

.. code-block:: python

def louie_value_update(network, node, value):

print('Hello from value : %s.' % value)

The start code

==============

We start the network

.. code-block:: python

network.start()

And we wait for the network. You MUST NOT use the network objects before

network is ready.

.. code-block:: python

for i in range(0,90):

if network.state>=network.STATE_READY:

print "***** Network is ready"

break

else:

sys.stdout.write(".")

sys.stdout.flush()

time.sleep(1.0)

We now change the name of the controller. You will have a notification.

.. code-block:: python

network.controller.node.name = "Hello name"

time.sleep(10.0)

Same when changing the location.

.. code-block:: python

network.controller.node.location = "Hello location"

time.sleep(120.0)

And we wait for 2 minutes. If you have sensors on your network, you will

see the value notifications on the screen. If you have switch or dimmers,

activate them manually, ...

Now stop the network and release objects.

.. code-block:: python

network.stop()

That's all :)

Full source code is in examples/hello_world.py

To see a more functionnal example, look at ozwsh code.