Things Bus: Difference between revisions
From Pumping Station One
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Before running the example, you must have a recent python, recent libzmq installed, and must have pyzmq installed. | Before running the example, you must have a recent python, recent libzmq installed, and must have pyzmq installed. | ||
<syntaxhighlight lang="python"> | |||
#!/usr/bin/env python | |||
import zmq | |||
context = zmq.Context.instance() | |||
# Create a zmq socket that will SUBscribe to door nodes. | |||
door_socket = context.socket(zmq.SUB) | |||
door_socket.connect("tcp://frontdoor.pumpingstationone.org:5556") | |||
door_socket.connect("tcp://backdoor.pumpingstationone.org:5556") | |||
# The doors send a lot of types of messages. We only care about "door.state.unlock" messages | |||
door_socket.setsockopt(zmq.SUBSCRIBE, b"door.state.unlock") | |||
# create a zmq socket that will PUSH data to our IRC actuator node. | |||
zirc_socket = context.socket(zmq.PUSH) | |||
zirc_socket.connect('tcp://sally.ad.pumpingstationone.org:5558') | |||
# Loop forever | |||
while True: | |||
# Read messages from the doors | |||
topic, message = door_socket.recv_multipart() | |||
# Send the message to the irc channel | |||
zirc_socket.send(message) | |||
</syntaxhighlight> | |||
== Hardware == | == Hardware == | ||
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For details of this system, see https://github.com/eastein/thingsbus | For details of this system, see https://github.com/eastein/thingsbus | ||
== Communication == | == Inter-Node Communication == | ||
{{ambox | |||
|type=content | |||
|text=The code snippits contain errors | |||
}} | |||
The software for a node can be written in any language that supports zmq and json. | The software for a node can be written in any language that supports zmq and json. | ||
Nodes send messages using json data. Sensors use zmq PUB/SUB. Actuators use zmq PUSH/PULL. Neurons use whatever they have to do get the job done, which means they SUB to sensors, and PUSH to actuators. | |||
=== Code Snippits === | |||
Sensors send data like this: | Sensors send data like this: | ||
import zmq | |||
context = zmq.Context.instance() | |||
socket = context.socket(zmq.PUB) | socket = context.socket(zmq.PUB) | ||
socket.bind('tcp://*:5556') | socket.bind('tcp://*:5556') | ||
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Neurons receive data like this: | Neurons receive data like this: | ||
import zmq | |||
context = zmq.Context.instance() | |||
sensor = context.socket(zmq.SUB) | sensor = context.socket(zmq.SUB) | ||
sensor.connect("tcp://sensor.tld:5556") | sensor.connect("tcp://sensor.tld:5556") | ||
sensor.setsockopt(zmq.SUBSCRIBE, b"dot.delimited.filter") | |||
topic, message = sensor.recv_multipart() | topic, message = sensor.recv_multipart() | ||
data = json.loads(message) | data = json.loads(message) | ||
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Neurons send data like this: | Neurons send data like this: | ||
import zmq | |||
context = zmq.Context.instance() | |||
actuator = context.socket(zmq.PUSH) | actuator = context.socket(zmq.PUSH) | ||
actuator.connect('tcp://actuator.tld:5558') | actuator.connect('tcp://actuator.tld:5558') | ||
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Actuators receive data like this: | Actuators receive data like this: | ||
import zmq | |||
context = zmq.Context.instance() | |||
socket = context.socket(zmq.PULL) | socket = context.socket(zmq.PULL) | ||
socket.bind('tcp://*:5558') | socket.bind('tcp://*:5558') | ||
