have a few arduino projects under my belt right now and i've been tackling a relatively ambitious project. I want to step it up a notch and have the arduino mega piggy back a cruise control system for my boat. It wont be going against the arduino guidelines as i'll just be using the arduino to simulate button presses. The thing that i need to figure out is how to know what speed the controller is set at so that i can display that information on my arduino's screen.
the module has an lcd gauge (thats not mine but its similar): http://img853.imageshack.us/img853/155/imagerwi.jpg
it looks to have a 10 wire harness.
i took it apart and noticed that the 4 buttons on the front panel had a handy 5 pin header and socket. (4 buttons, 1 common ground) http://onfinite.com/libraries/1663907/87b.jpg
i also found this device online that lets you control the speed wireless while being towed: http://www.nautiqueparts.com/wirelessremoteforcruisecontrol.aspx (speed up/ slow down)
this leads me to believe that the button presses are not serial and and the connect directly to digital inputs on the master module. that would leave 6 wires on that harness for the display. two of which are power and ground. that would lead me to believe that it's a serial lcd? (edit: i contacted the person who made that and the buttons do extend out from that wire harness.)
now to my question... does my logic sound correct? and if so. being new to coding and micro controllers. would sniffing out the speed settings that are being sent to the lcd screen be within a novice's grasp? and do you guys recommend any online tutorials/videos (or if you'd like to post directions here... id love that too) that would show me the correct ways of accomplishing this task?
thanks in advance