System use cases and refrigerator experience


Author introduced real-time sensor platform service and implemented the real application with Arduino and sensors.

Author says,

SAWA can be considered as a platform, with a set of services and web application. It uses XMPP Protocol to transport all sensor data in real-time, and allowing secure connections.


He says about his use case example (Monitoring a refrigerator),

I used this experience to test the system, so the objective was to record sensor data.

The variables I selected to record was: door status(open or closed), time open (number of seconds the door was open), and temperature.
Since arduino is very resource limited, i used HTTP POST method to publish data.


  • sensors
    • 1 temperature sensor
    • 1 photo-resistor
  • devices
    • 2 arduinos
    • 1 ethernet shield
    • 1 RF kit

Network diagram

Sensor Network diagram
Sensor Network diagram

– The arduino on refrigerator sends messages to gateway (arduino in router) with format msg_id:sensor_variable:value (example: 455:door:1:temperature:10)
– Then gateway sends via HTTP POST the sensor value with user credentials and sensor identification
– Then on server, this data is published to XMPP node


Sensor gateway (Arduino Ethernet)
Sensor gateway (Arduino Ethernet)





Salvador Faria





Please Login to comment
Notify of