6 motors controlled via ethernet with game controller

[Bennachie]

Regarding your code, I think you are nearly there. Problem is, it only takes one tiny error to make the whole thing not work!

I see two options.

1. Start to simplify the code. Break it down in to sections that can be got working easily and debug each section. On the plus side, you'll learn a lot about coding this way!

2. Use my working code but change your joystick input method from USB to analogue. You could even dismantle your USB joystick and use the outputs from the potentiometers and buttons and feed them directly in to the topside Arduino. Or you could buy new analogue sticks & buttons.

As for transferring power from the surface, you have hit upon a well known problem. I posted some replies to this in a thread in the 'electronics' section. The thread is called 'pros and cons of external power'.

You can either use AC or DC high voltage to transfer the power. Be aware- both are potentially dangerous!

Both methods have pros and cons. AC requires either a generator or an inverter at the surface. Generators are heavy and noisy. Inverters are horribly inefficient. AC requires fitting a transformer and rectifier in the ROV.

DC requires using isolated DC-DC converters both on the surface and in the ROV. Step up converters, which convert a low voltage to a higher one and therefore would be used on the surface, tend to be fairly low power, but if you make sure to use isolated ones, you can connect them either in series or parallel as required. Step down converters convert a high voltage to a low one, so would be used in the ROV, are a lot more powerful but tend to be quite large.

Take a look on the RS website. You'll find it possible to use DC-DC converters to convert from 12V to over 100V at about 5W, so you'd need to parallel two or three together. You can also find converters to convert from around 100V back down to 12V, but they are not small.

[Scanro]

Regarding your code, I think you are nearly there. Problem is, it only takes one tiny error to make the whole thing not work!
Take a look on the RS website. You'll find it possible to use DC-DC converters to convert from 12V to over 100V at about 5W, so you'd need to parallel two or three together. You can also find converters to convert from around 100V back down to 12V, but they are not small.

I checked out RS and I found a switch mode powersupply from Tracopower that can do 12V and 5.42A DC with a 85 -> 264V ac input range. I know that I would need 6 of them, but it really seems like the best option, since then I can run AC down to the sub and get enough DC power to my ESC and well the motors to get a decent amount of thrust. I have also spent quite a lot of time looking at (not sure if this is the correct english term) ring iron core transformers, but they get rather large and then I would still need to get a AC to DC transformer, which isn't ideal given the limited space.

[Bennachie]

If you plan to use AC at the surface then that route is the sensible one. You could use a transformer and make your own full wave bridge rectifier, but as you say transformers can get quite big, so the TRACOs are a convenient solution, if a little expensive sometimes.

[Scanro]

If you plan to use AC at the surface then that route is the sensible one. You could use a transformer and make your own full wave bridge rectifier, but as you say transformers can get quite big, so the TRACOs are a convenient solution, if a little expensive sometimes.

I think that using AC at the surface would be the most sensible mainly based on the extra bulk going pure DC on both sides will probably add in the end, at least based on my research for the past few days. But yeah they are quite expensive, I still have to go over this with my friends to see if we can afford to do this, but it seems doable right now.

My original idea was actually to make my own full wave brudge rectifier, but that got shut down at least for now because of the size. And thanks for all of the input and help so far.

[Oddmar]

IMHO, putting batteries in the ROV eliminates all these problems/ safety concerns. I would never consider running power down the tether. Without batteries in the ROV, when you (or the autopilot controller) revs the thrusters, there is a voltage drop that can 'brown out' your control electronics.

I use batteries for ballast in seperate WTC's. I figured if i needed ballast anyway why not take advantage of batteries being heavy (commonly).

I use (24) 6V 12AH SLA batteries in two custom-built aluminum housings, but in the future when i become rich (lol) i may switch to LiFePo4. My batteries are charged at 12V but when plugged in put out 18VDC with 96AH onboard.
https://www.amazon.com/YUASA-NP10-6-10A ... 87&sr=8-16

Most hobbyists won't be building such a large ROV though, and could afford the LiFePo4 batteries due to the reduced quantity needed.
https://batteryhookup.com/collections/l ... teries-new

[Scanro]

If you plan to use AC at the surface then that route is the sensible one. You could use a transformer and make your own full wave bridge rectifier, but as you say transformers can get quite big, so the TRACOs are a convenient solution, if a little expensive sometimes.

just to go a bit back what video transmitter do you use? I have been looking a bit on hobbyking and I found a RunCam Split Mini FPV/HD Camera, but I can't quite find a wired transmitter.

IMHO, putting batteries in the ROV eliminates all these problems/ safety concerns. I would never consider running power down the tether. Without batteries in the ROV, when you (or the autopilot controller) revs the thrusters, there is a voltage drop that can 'brown out' your control electronics.

sadly because of the operating time we want out of it batteries aren't really an option, at least not without it getting too big and heavy for us.

[Bennachie]

just to go a bit back what video transmitter do you use? I have been looking a bit on hobbyking and I found a RunCam Split Mini FPV/HD Camera, but I can't quite find a wired transmitter.

I'm using fibre optics, but as you will presumably be using copper, you should use a pair of video baluns. They convert the video signal from an unbalanced signal to a balance line pair signal, a bit like the equivalent of RS-485 but for video.

For example-

https://cpc.farnell.com/defender-securi ... gKw2vD_BwE

These ones are passive, so no power required. They will almost certainly be suitable. You can also get powered ones, but I doubt you'd ever need that.

You simply fit one at the top and one at the bottom. They will drive the video signal up your tether.

[Scanro]

just to go a bit back what video transmitter do you use? I have been looking a bit on hobbyking and I found a RunCam Split Mini FPV/HD Camera, but I can't quite find a wired transmitter.

I'm using fibre optics, but as you will presumably be using copper, you should use a pair of video baluns. They convert the video signal from an unbalanced signal to a balance line pair signal, a bit like the equivalent of RS-485 but for video.

For example-

https://cpc.farnell.com/defender-securi ... gKw2vD_BwE

These ones are passive, so no power required. They will almost certainly be suitable. You can also get powered ones, but I doubt you'd ever need that.

You simply fit one at the top and one at the bottom. They will drive the video signal up your tether.

Thanks for the link and explanation