I'm building a small rov (3motors). to control it im planing to use arduino board to connect joystick with pots (only for movement left right forward and reverse) , and one sliding pot for up n down. Now, problem is im not that good in C. Please help me with the code or if u know when can i get samples
If I were going to build such an ROV (I am still assuming an underwater craft here; you haven't said otherwise) , I would actually use two Arduinos; the one on the ROV for decoding commands, and another on the surface sending the commands via the tether.
Based on your description, you are looking at building a tether for at least 3 potentiometers, and power. That will need a minimum of five wires in the tether. As you add peripherals (lights, video, etc) you are likely going to need more wires in your tether. The more wires, the heavier the tether, needing more powerful motors, etc.
Nip that idea in the bud immediately; go with a simple tether consisting of as few lines as possible. The easiest would be to use Cat5e with stranded core wires (not solid core); if you can find it with a silicone outer jacket, that would be even better (though more pricey). If you are working in a swimming pool environment or the like, then a standard jacket will be OK; but you will still want stranded core wires, because of the flexing as you reel it in/out.
Cat5 makes a pretty good tether, from what I can gather; its lightweight, flexible, fairly waterproof (provided the end points are sealed), and is designed for remote, long range electronic communications. The difficult part is reeling it in/out - I remember finding one guy's solution was to build a reel for his tether, and the reel had sliding contacts of brass loops and springs, so that he could reel in/out the tether as needed, but that communications wouldn't be interrupted, plus there wouldn't be tangling (as involved with just a manual coil of cat5).
With such a tether, you have 8 wires; you could continue with your plan of using those wire connected to potentiometers, switches, etc - but what would be better would be to wire two Arduinos together in a serial communications system, so that one (the topside controller) interprets the joystick/potentiometers values, then sends those down to the controller in the ROV, which uses those commands to activate the thrusters as needed (and/or switch lights on/off, command a gripper arm, send back telemetry data on heading/attitude/water temperature/etc).
Such a system would only need two wires of the eight available for transmit and receive; You would want to either have an on-board battery on the ROV for power, or send it down via two of the pairs on the tether (so, four wires - 2 for power, 2 for ground - because of likely current requirements, plus redundancy). If you send the power via the tether, that leaves two wires left; use those for an on-board video camera on the ROV (some of the telemetry info could also be sent up via video if you use one of those video overlay boards that exist out there).
If you need some ideas (and possibly some code direction), check out this guy's site:
He uses an AVR platform, so some of the coding ideas may translate over to the Arduino. Other example code for what you would need (serial communications, PWM control of motors, reading potentiometers, etc) can all be found in the playground as well as in the examples that come with the Arduino IDE. The rest can be found on this forum.
Also note that there are a ton of sites out there geared toward people developing their own ROVs (and UAVs, but curiously, very few for developing UGVs - not sure why, though).
