AirMobile - 20 - Bluetooth protocol

amgalbu

13 Jan 2015

Bluetooth protocol

Everytime I search something in the opensource community, a quote from Isaac Newton comes into my mind

"We are dwarfs on the shoulders of giants"

It's unbelievable the health of information is available for you to give form to all your ideas!!

I was looking for an Android application that I could use as a starting point. The main requirements were very simple

Connect via Bluetooth to the AirMobile sensor
Cache data local visualization
Push data to the AirVantage cloud through MQTT

I was very lucky because I found an application that also met my idea about the Bluetooth protocol (see my post here) The application Bluetooth protocol is a very simple one-way (from sensor to application) procotol and so I decided to adopt it for the AirMobile sensor.

Here is the protocol specifications:

The Sensor package name is the external sensor name (in this case "AirMobile")
The Sensor name should be different for each sensor.
Type of measurements is a string that identifies what we are measuring
Short type of measurement is used (in my case) internally to identify the dataset to update in the AirVantage cloud

T1..T5 are integer thresholds which guide how values should be displayed -
lower than T1 - extremely low / won't be displayed
between T1 and T2 - low / green
between T2 and T3 - medium / yellow
between T3 and T4 - high / orange
between T4 and T5 - very high / red
higher than T5 - extremely high / won't be displayed

Just to give an example, the AirMobile sensor will send out strings like this

  23.5;AirMobile;TMP36;Temperature;temperature;degrees Celsius;°C;-40;-10;30;40;60
  55;AirMobile;HIH4030;Humidity;humidity;percent;%;0;25;50;95;100");
  10;AirMobile;TGS2442;CO ppm;co;ppm;ppm;30;40;100;500;1000
   20;AirMobile;MiCS-2710;N02 ppb;no2;ppb;ppb;200;200;500;1000;2000
  100;AirMobile;SharpGPY;Dust;dust;ug/m3;ug/m3;0;10;300;490;500