Sounds like we're doing the same project!
I've been working on a sub for a few months now ( on and off ), basic layout is this:
- usb webcam connected to the a usb-lan adaptor
- 40m umbilical chord made up of lan cable + power cable
- 3 modified bilge pumps for movement
- 2x salvaged torches for lights
- arduino + adafruit motor shield for control of motors and lights
- controlled from suface using wiimote connected to laptop
- Small pressurized container made from clear perspex for electronics
- outer shell made from plumbing parts
- Temp sensor, leak sensore and compass
although you've clearly put a lot more effort into the design - looks great!
I am quite curious why you need 4 wires for the nunchuck? Or for that matter more for future developments? Are you planning on having the arduino on the surface or in the sub?
I went down the route of making the laptop on the surface talk to the arduino in the submarine ( via uart ), its sends it requests ( like lights on, dive, torpedoes ) and the arduino sends back status info ( like leak detected, compass heading ). That way I only have 2 wires for control and as I add more peripherals to the arduino I only have to make changes to the software ( thinking about pan/tilt for the camera next ).
Something I have found - the specs for the usb-lan connector said 50m lan cable, 40m if using a usb hub as well. This didn't work - I had to cut it down a bit - I think my umbilical is closer to 30m and I still cannot use a usb hub ( was planning to have more than one webcam ).
I'm just in the process of finishing off the code for the pc - wiimote bluetooth connection then I should be launching it ( hopefully next weekend ).