Tuesday, March 30, 2010


I finished up my bachelors degree in Electronics Engineering at ITT in Tucson, June of 2006.
My final project, along with Tom Gross and Ronald Trinh, was an under water vehicle.

The construction of the frame was made from PVC pipe from the local hardware store, and the pressure chamber was made from a small Pelican case. Being a single hinge with clip lock, the pressure chamber was only good for less than 50 feet of depth, but good enough for a proof of concept.

Mounted in the case were all the electronics, as well as a small pinhole camera. Power and control signals were fed into the case via an umbilical cord, made from cat-5 cable. Two pairs of wire were used for power (one pair serving as +, one as -). One pair of wire was used for RS232 communications. Finally, one pair of wire brought back the video signal to a small LCD display.

The PCB carried a 5-volt linear regulator, as well as a pic16f877 micro-controller from Microchip Technologies. This chip had simple firmware written in PicBasic. The firmware handled all the communications via RS-232 to a laptop. In addition, using a simple state machine, it switched on the various motors of the ROV, via a standard power transistor.

The motors that moved the ROV around were bilge pumps made by Rule. All wires going into the Pelican case were first glued into a short piece of tubing with pvc caulking. Next, the wires were passed through a hose barb mounted in the case, and the tubing slipped over the barb, forming a water tight seal. Finally the wires could be connected to the PCB using screw terminals mounted to the board.

Since finishing the project, I have had a lot of time to consider all the improvements that could be made. In addition, I have joined and followed the discussions on a home-built ROV group. As such, I have been planning and am now in the circuit design and PCB layout stages of a new ROV, which will rival many commercial units, yet offer the electronics package at a price in which many can afford. My plan is to target small agencies that may be strapped for cash, in wetland areas. Agencies such as search and rescue, police departments, wildlife and fisheries, and emergency response units need small portable ROVs to work in rivers and lakes, which are of of low cost, as well as being easy to maintain. However they still need many of the same features of the mid-class inspection ROVs.

I will be making future posts as the project develops.

The original ITT-ROV project can be found here:

The posts have also been added to THIS blog. You can find them simply by clicking the ROV link on the left.

No comments:

Post a Comment