JP ROV update

[jpWA]

I finally got all the major parts and have put together most of the wiring and onboard electronics
I have an arduino connected to 3 dual H-bridge motor drivers for the thrusters and some relays for the lights and claw, the Ardiuno usb port and the camera are both connected to a usb hub, which will go to a usb to RS232 converter, with the serial cable going to the surface. Onboard power comes from 5 11.5v lithium batteries linked together for a total of 11 amp-hours

IMG_0481.jpg (449.9 KiB) Viewed 4784 times

I added a claw because... ummm... It's cool

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IMG_0484.JPG (719.52 KiB) Viewed 4784 times

The batteries go in the left pipe and the electronics go in the right.
I was planning to have an emergency cutoff system where if water got into either pipe, a connection between 2 contacts would trip a relay which would cut off power to everything else. However, ever when I used a small relay to control the big one that switches off main power, fresh water is just not conductive enough, even if the contacts are very close together. So I could either put salt inside the tube (which actually now seems like a really bad idea), or just abandon the whole system. Would fresh water even harm the electronics? If so, I'll probably put them in vacuum sealed plastic bag (I don't trust my watertight sealing around the lights).

[Sunktwice]

Nice - cool claw

Which H-Bridge units did you use ? are they the 3A rated ones ? Reason i ask is i'm still waiting for a set, and wondered how they perform ?

If you want to get a leak safety cutoff in there, use your arduino - either use a piece of strip board and a resistor and code in a pin HIGH-LOW block, or buy a cheap rain sensor pad from eBay - there are a few out there with an I2C board so coupling it to the arduino is a piece of cake - and, as it's there to detect rain (fresh water)- so your on to a winner

linky below.
Water/Humidity sensor

[jpWA]

This H-bridge, http://www.aliexpress.com/store/product ... 69334.html, is rated to 43A and works from 6 to 24v.
I hoped to have leak protection based on basic circuitry so it could work in the battery housing, while keep the number of wires between the two housings to a minimum. (by that I mean that i've already done the wire penetration on the battery housing and I really don't want to redo it)

[rovdude]

the Ardiuno usb port and the camera are both connected to a usb hub, which will go to a usb to RS232 converter, with the serial cable going to the surface.

How far does your rs232 go? I was trying to figure out a way to get my usb camera to surface too

[jpWA]

Actually, I think I'll use a cat6 converter like this one:
http://www.monoprice.com/Product?seq=1& ... 7AodolEAtA

As long as the control signal to the arduino is at a low baud rate, there should be enough room for both signals from the USB hub.

[rovdude]

Actually, I think I'll use a cat6 converter like this one:

I have those now. Keep in mind it reduces the speed from USB 2.0 to 1.1, giving a very grainy picture usually

[Players753]

Hi I'm new to the rov's what kind of motors are the ones in the picture

[jpWA]

rovdude: Thanks for the warning, I'll try to find one that works with 2.0

player753: they are Rule in-line bilge blowers
http://www.xylemflowcontrol.com/special ... lowers.htm
they are designed to work in air but seem fine in fresh water, and you can get them from amazon or at a boat store

[merbass]

Do you know how many amps the bilge blowers are pulling?