boat navigator/autopilot

[Darth-Hördur Jonsson]

I have a project thats in its "planning" stage (long term) that i think others might find interesting.

 

Simply put, its a autopilot for your boat, controlled with a micro computer (pic was initially intended) using a standard rc servo interface.

The required hardware is (so far); computing unit, gps, digital compass, accelerometer (to compensate compass) and user input.

 

It has recently come to my attention that such servo interface is easily built, gluemotor(dotcom) is my latest and dearest search result.

A decent servo control is achieved by using the audio output as data carrier (pwm) meaning that any android phone, with the correct software, can easily be used as a autopilot, since they already have all the neccisary sensors.

An external battery is needed for the servo´s.

 

As far as i can understand googles ambition with android, most of the core functions are easily accessed thru the api, witch means access to all the sensors already exist, its "simply" the matter of cut/paste of functions or external calls to aditional applications.

 

so the basic idea is to get a gps fix, compare it to a target gps position to get a bearing to target, then compare current course to target bearing and use PID http://en.wikipedia.org/wiki/PID_controller to determine ajustments needed to servos.

 

since the output is stereo, a second servo can be attatched to control throttle and therefore speed aswell.

And since we´re out there i might just aswell mention that the headphone jack also has a microphone input. is it possible to connect a sonar transceiver and have the smartphone double as a fishfinder? :)

 

Now, what do i need to learn to achieve this?

or is there anybody out there thats up for a challenge? :)