Chandra’s Blog

In continuing with my experiments with IoT,

I was googling for ways to send mobile phone data (battery level, GPS location) to a centralized server using MQTT.   The nice thing about a MQTT broker is that it is light weight (compared to other message bus and is well tuned for sensor data; further, it also has some QOS as part of the protocol).

 

Step 1:

I setup a Mosquitto based MQTT broker  (on an Ubuntu 12.04 laptop)

http://mqtt.org/

sudo apt-get install mosquitto
sudo apt-get install mosquitto-clients

su /etc/init.d/mosquitto start
su /etc/init.d/mosquitto stop

Testing:

to subscribe – mosquitto_sub -d -t hello/world

to publish – mosquitto_pub -d -t hello/world -m “hello”

Step 2:

I looked for a mobile app – fortunately OwnTracks (http://owntracks.org/  and https://github.com/owntracks/ios seem to be the best choice).  It is a small app (also available for Android) that sends geo-location to a MQTT server (set up above – all this would be inside a private network).

I downloaded the owntracks app from Apple store and configured it to send data to the server above.

Note:

The MQTT server does not store any information.

On the laptop – mosquitto_sub d -t owntracks/chandra/iphone

On the iphone owntracks app – choose Host ip address (laptop address), default port (1883) and Topic owntracks/chandra/iphone

A quick way to test is to press the square blue button on top (Location Monitoring Mode) and click on ‘Public Now’ button – this will send out a MQTT packet to the MQTT broker (you will see it on the laptop window that is running mosquitto_sub program)

Date: Tuesday, April 14th, 2015 at 11:07 am | Category: IoT | RSS Feed: RSS 2.0 feed.
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