Tethered Control with Analog Inputs to Arduino

Using Arduino Project Guidance
1

Hello all, I am currently working on a senior design project. My team is designing and building a Remotely Operated Underwater Vehicle. The current design is utilizing a 50ft tether. We are using 50' of 12 gauge wire for power, a 50' video line, and a 50' ethernet line for analog control of the thrusters. The ethernet line will be connected to an analog joystick at the surface which will then be routed to the Arduino aboard the ROV via a 50 ft ethernet line. My concern is using analog control over such a long distance of wire. What issues, if any should I expect by transmitting analog voltage signals over a 50' ethernet line?

Also, what would be the best way to implement RS-485 communication between a master and slave arduino?

We are a team of Mechanical Engineers with limited electronics exposure, any help is greatly appreciated.

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Previous post concerning ROVs. Your setup has a lot of wiring. Excluding power, you probably could do your control and video over thin four conductor cat3 telephone wire. Put a router on the ROV and use a 10BaseT connection over the telephone wire to connect to a router on top with an arduino and pc connected to it.

https://www.google.com/search?hl=en&as_q=rov&as_epq=&as_oq=&as_eq=&as_nlo=&as_nhi=&lr=&cr=&as_qdr=all&as_sitesearch=http%3A%2F%2Farduino.cc%2Fforum%2F&as_occt=any&safe=images&tbs=&as_filetype=&as_rights=

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Is there a way that I could control the 6 thrusters onboard the ROV via communication from an Arduino at the surface to an Arduino aboard the ROV?

Also, besides a lot of wiring, will the current design in the OP work reliably?

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Is there a way that I could control the 6 thrusters onboard the ROV via communication from an Arduino at the surface to an Arduino aboard the ROV?

Probably. If you run enough wires, you won't need an arduino, you could just use toggle switches or push buttons on the surface.

Also, besides a lot of wiring, will the current design in the OP work reliably?

Possibly, depending on your ability to put it all together. So, what have you done so far in testing your design?

5

I have functioning code that I tested with LEDs, I basically made sure the right LEDs lit up for a given analog input from a potentiometer. This however was using 5 inches of wire. My concern is the vulnerability of the voltage inputs on the 50 foot ethernet line to fluctuate with small disturbances ( main disturbance would be the current running in the power line for the ROV).

I have ran a test using 50' of 22 AWG wire as the input line from the pot to the Arduino. The only way I could create a disturbance was by wrapping the line around a power tool's frame (AC engine). I also wrapped the wire around the power tool's power cord but no disturbance was seen in this case.

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I'd suggest using an arduino on the ROV, and on top have another arduino or a PC and use simple rs232 communication between the two.

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I am completely lost in trying to code RS 232 communication between Arduinos. How hard is this and where can I find good info on it? I am doing a ton of googling on it and finding some good info but any more help is appreciated. Thank you!

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Start by using the serial monitor in the arduino IDE. Go to file > examples > communication and look at the serial examples.

9

Rather than searching for "RS 232 communication" try "serial communication" because the RS-232 bit has nothing to do with the software.

This is a VERY common subject on the forum so you should be able to find plenty of threads about it.

Rob