Example: MQTT

What is MQTT?

MQTT is a machine-to-machine (M2M)/"Internet of Things" connectivity protocol. It was designed as an extremely lightweight publish/subscribe messaging transport.

Requirements

Install MQTT server:

sudo add-apt-repository ppa:mosquitto-dev/mosquitto-ppa && sudo apt-get update && sudo apt-get install mosquitto

Install MQTT and BlinkStick Python packages

sudo pip install mosquitto blinkstick

Files

Create file listen.py and paste the following text:

#!/usr/bin/env python

from blinkstick import blinkstick
import sys
import mosquitto

def on_connect(mosq, obj, rc):
    print("rc: "+str(rc))

def on_message(mosq, obj, msg):
    sticks[0].set_color(hex="#"+str(msg.payload))
    print(msg.topic+" "+str(msg.payload))

def on_publish(mosq, obj, mid):
    print("mid: "+str(mid))

def on_subscribe(mosq, obj, mid, granted_qos):
    print("Subscribed: "+str(mid)+" "+str(granted_qos))

def on_log(mosq, obj, level, string):
    print(string)


def main():
    global sticks

    print "BlinkStick MQTT script"
    print ""

    sticks = blinkstick.find_all()
    if len(sticks) == 0:
        print "BlinkStick not found..."
        return 64

    mqttc = mosquitto.Mosquitto()
    mqttc.on_message = on_message
    mqttc.on_connect = on_connect
    mqttc.on_publish = on_publish
    mqttc.on_subscribe = on_subscribe
    mqttc.connect("localhost", 1883, 60)
    mqttc.subscribe("blinkstick/color", 0)

    rc = 0
    while rc == 0:
        rc = mqttc.loop()
    
    return 0

if __name__ == "__main__":
    sys.exit(main())

Create file send.py and paste the following content:

#!/usr/bin/env python

import mosquitto

mqttc = mosquitto.Mosquitto()
mqttc.connect("localhost", 1883, 60)

mqttc.publish("blinkstick/color", "00ff00")

Running

Make sure you have BlinkStick connected to the computer and start the listener:

python listen.py

Open up another terminal window and run the following command to set the color of BlinkStick to green (#00FF00):

python send.py

Alternatively you can set the color with the mosquitto_pub command line tool:

mosquitto_pub -h localhost -t blinkstick/colour -m 00ff00

Idea

Thanks to Andrew D Lindsay ‏@andrewdlindsay for coming up with this idea!

BlinkStick.com

This solution gives you a local version of remote control for BlinkStick. If you want to control your BlinkStick with your mobile device or share it with somebody else via Internet, you can find all information how to connect it to BlinkStick.com in the tutorials section.