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Journeying 20,000 leagues under the sea, Jason built this underwater Remote Operated Vehicle (ROV) so he could explore the depths of his bath tub, swimming pool and beyond. Employing mostly off-the-shelf parts, the ROV is controlled via Visual Basic commands sent over an RS232 serial port. Powered by bilge pump motors and equipped with a video camera, the ROV was developed on a flexible platform that will allow the addition of advanced capabilities such as joystick control, temperature/pressure sensors, air lift balloons and sonar.
This Gadget Master originally appeared in our sister publication, Design News.
1. Assemble the PVC pipe hull as shown below. All pieces are off the shelf parts. The only parts that need to be cut to length are the 2″ pipe. This can easily be done with any hand saw. Glue all pieces following the direction on the PVC glue you purchased. On any threaded part be sure to use plenty of Teflon plumbers tape to prevent leaks. Part number 1 in the diagram above is the 2″ union this part needs to be put on with the rubber gasket closest to the main body of the ROV. These gaskets seal the ROV windows.
2. Let the PCV glue dry over night, then use white plastic prime to paint the ROV, then after that is dry paint the ROV with Yellow paint. Paint the ceiling tile grate black.
3. Disassemble the Flash lights. Keep only the reflector. Remove the bulb and replace with a 12V low watt bulb (too high will melt the plastic reflectors). Solder 24″ red and black wire to the battery tab and to the metal ring of the reflector. You will have to cut and sand down the reflectors to fit inside the PVC unions, but they are a very close fit.
4. Cut the ceiling tile grate in a U shape to fit between the PVC pipes. Use the black cable ties around the PVC pipe, and through the ceiling tile grate.
5. Mount the bilge pump motors as shown, with the nozzles pointing in the correct direction. The bilge pumps are mounted to the ceiling tile grate via ¼-20 bolts and nuts and large fender washers.
6. The wires are bundled together and woven between the grates and cable tied. The wires are not long enough from the bilge pumps so there need to be wires soldered or butt connectors put on them (they need to be extended about 3 feet). For the enter in the sub all 12 wire must fit into through a hose barb and vinyl hose. Run wires into center 4″ tee.
Water proof connector
Build Ethernet connector as shown above leaving feet of wire on the inside.
7. Run the hoses for the thrusters as follows, and cable tie where appropriate. The hoses can be tipped with hose barb reducers to increase thrust if needed. I used U bolts to go around the back and entry point to the large center tube. To help aim the up/down and forward hoses.
8. Build the circuit by either making circuit board if you are familiar with that or build the circuits on a perf board following these schematics. If you need more detail, or info on the the board layouts they are available at my web site www.rollette.com/rovrev2
9. The program for the Mega32 is available from my web site. It is written in basic using the Bascom Program from MCS ELECTRONICS. It can be downloaded here:
http://www.mcselec.com/index.php?option=com_docman&task=cat_view&gid=99&Itemid=54. There are tons of user groups to help with AVR programming I use this one: www.avrfeaks.com.
10. The ROV is controlled via a visual basic interface that looks like this. There are commands are sent via the RS232 serial port. This program was written for me by a great guy that found my web site Bill Travis.
Here are the serial commands from Visual Basic or HyperTerminal. The values are a lower case letter each followed by a value from 0-9 and a carriage return. Value “0” being off. a0-9 = Forward, b0-9 = Reverse, c0-9 = Left, d0-9 = Right, e0-9 = Up, f0-9 = Down, g = Ping, h = Air Lift, i = Torpedo, j = Aux1, k0-9 = ballast, l0-9 = Lights, m0-9 = IR lights.
Commands received from processor: When the sub is first turned on it sends back “Ready”.
Commands are in UPPER CASE followed by a number in the range ex.: C56 means the compass is sending back a reading of 56 degrees. C Compass direction (in degrees) 1-360, L Leak message 0 = no leak, 1 = leak, P Pressure (in PSI) 0-500, TI Internal ROV temperature (in degrees Fahrenheit) 0-100, TW Water temperature (in degrees Fahrenheit) 0-100, V Battery Voltage 1-20, X -90 – +90 tilt angle(front to back vertical), Y -90 to +90 tilt angle(left to right horizontal).
11. The Ethernet cable needs to have floats every 10 feet or so to keep it semi afloat I used hose insulation cut in 1.5″ lengths and cable tied every 10 feet or so.
12. Here is the finished ROV in the water.