Sending compass sensor info to laptop via Bluetooth

[Joao Barcia]

Hi everyone, I would like to code a simple program that would send (either continuously, or upon pressing a button on the screen) the compass coordinates (lat, long, bearing) to a laptop via bluetooth. Is DroidScript suitable for this? I will start working on this project next week, just wanted to be sure if I should invest time with DroidScript, or consider an alternative.

Thank you very much!

[Dave Smart]

Hi Joao,

It depends on what you are planning to do on the laptop end.  DroidScript can talk via Bluetooth Serial or Bluetooth LE, but you might want to consider using WebSockets if you have a Wifi access point available (or running on your laptop).  

What are you going to code the PC end in?

You could simply run a browser on your laptop (if you have Wifi available) and then run a web server inside DroidScript. 

Regards

David

[Joao Barcia]

Hi Dave,

Thanks for the quick reply. Turns out "email updates to me" wasn't turned on by default so I just got to see your reply now.

The plan is to use droidscript to send GPS and Compass info to a laptop. Another source connects to the laptop to give distance to a remote object. The laptop calculates GPS coordinates of the remote object and stores it.

Is there any straightforward way to calculate the compass true north value from the magnetic sensor?

Cheers

[Dave Smart]

Probably best to use the 'Orientation' sensor.

Check here for some sample code:- https://groups.google.com/d/msg/androidscript/5AuPNLN9DDo/7LAjhP_hReYJ

Getting true north from the magnetic north (azimuth) value might not be straight forward though.  You might need to hunt for a JavaScript function to do it for you.

We probably need to add it DS in the future like this:-

http://stackoverflow.com/questions/5479753/using-orientation-sensor-to-point-towards-a-specific-location

[Joao Barcia]

Hi Dave,

Exactly. After some research it turns out that it seems that good compass programs actually use a mix of the Magnetometer, the Orientation sensor, GPS and some calculations about magnetic deviation (which I didn't know existed until today https://en.wikipedia.org/wiki/Magnetic_deviation).

Will take a look at it. Thanks