Need camera advice

[jpWA]

I have been trying for a few months now to successfully waterproof a cheap USB webcam, only to find that the autofocus won't work underwater.
I had been planning on connecting the camera and arduino to a USB hub, linked to my laptop on the surface by usb signal booster cables daisy chained together, but this won't work with more than one booster cable for some reason.

Now I want to use RS232 for the arduino and either 232 or 485 for the camera, using USB converters to connect to my laptop. Serial board cameras are more expensive and I would like suggestions if anyone knows one that they could recommend.
These are a few that I am considering.

http://www.alibaba.com/product-detail/- ... 54061.html

http://www.securitycamera2000.com/produ ... 7AodDg4A8g

http://www.securitycamera2000.com/produ ... 7AodzScAJA

[rossrov]

Hi jpWA. USB won't work over a certain distance because of the time taken for the signals to travel back and forth in cable. Google "propagation delay". This limitation is set in the USB specification. USB was never designed for any distances much further than desktop use. Apparently daisy-chaining hubs can be used to extend, but by the time you mess around with that there are much easier ways to send video along a tether.
I apologize if I misunderstand, but seems you are trying to find out if video can be sent via RS232. The serial cameras you linked to refer to sending additional data via serial, such as PTZ, not the video. Some cheap board cameras can do serial imagery that can be sent via RS232 or similar, but these are only still images, not video. The data rates required for video would typically be too high for RS232.
You might consider using a cheap composite output board camera, a video balun in the ROV, one pair of wires in a cat 5 cable tether, another video balun and a video to USB converter at the PC. I have not tried this out myself, so do not know what sort of delay or latency there would be due to the video to USB conversion. Converters are cheap, and you can test that on the bench before buying the baluns.

[jpWA]

The extender cables that I bought had a circuit board at the far end to boost the signal, and the packaging said that several of them could be daisy chained, but I guess the packaging can't be trusted.

Sorry if I wasn't clear enough, but I was not sure what communication protocol to use for the camera, and I guess I'll use RS485 for both the camera and arduino even though all of that stuff is more expensive.

This one appears to actually take real time video, from the demo on the website, but It's just a lot more than what I want to spend on a camera without knowing anything other than what's on the website, and I hoped someone could recommend it or a similar camera, or recommend methods to pressure-proof it without ruining it.
http://www.securitycamera2000.com/produ ... e-OSD.html

[Bubbles]

This one appears to actually take real time video, from the demo on the website, but It's just a lot more than what I want to spend on a camera without knowing anything other than what's on the website, and I hoped someone could recommend it or a similar camera, or recommend methods to pressure-proof it without ruining it.
http://www.securitycamera2000.com/produ ... e-OSD.html[/quote]

A similar camera that I am thinking to use if I don't use Gopro is this one:
http://www.camonetec.com/de/produkte/ka ... daten.html

[rossrov]

jpWA. The camera on the link uses RS485 to send on-screen-display data and other commands TO the camera. If this is what you want to do then great. You will still need some other cable to get the video back to your monitor. NOT RS485, 422, or 232.

Bubbles: Off-topic, but that's a nice looking camera for HD recording. I had a look at the English version user manual on the website. Pins "L" are marked video out. I assume this is composite video, real-time, that can be sent up the tether. Also there are other pins for recording start/stop etc. Easier than modifying something already in a case.

[jpWA]

Been busy this week

jpWA. The camera on the link uses RS485 to send on-screen-display data and other commands TO the camera.

Glad someone caught that, but I'm not worrying about trying to overlay anything onto the video. The description says it has HD-SDI and CVBS BNC outputs. Would a converter like this work if it was just plugged into a laptop?

http://www.dealfocal.com/Computer-Cable ... 25966.html

[rossrov]

That's the sort of thing I'm referring to. The link you posted caused a security warning on my PC, so i searched for it elsewhere. You can get much cheaper ones, just with an RCA connector and not BNC. In the ROV you may be cutting off connectors and solder splicing or soldering direct to the PCB to save space.

As to the camera, I bought a car reversing camera for another submersible but non-ROV project a few days back. It was about $12. These will work with the converters.

cheers,
Ross

[jpWA]

...So analog video is fine over distances around 50ft. Is this camera similar to the one you used
http://www.bestbuy.com/site/agptek-nigh ... 1304644204

And as for the converter, would a cheap one like this work
http://www.lightinthebox.com/usb-2-0-tv ... tely_buy_1

Or would I need a more expensive one like this
http://www.brickhousesecurity.com/produ ... s+input.do