This is the first try at an underwater remote controlled vehicle
(ROV).  It was somewhat successful. No leaks and battery power
was sufficient.  Video back to the surface was good. Thruster
became erratic after 10 minutes of operation so I'll be looking at
improvements to the DC motor drive circuits.  We expect to use
this as a development platform for grippers, depth control, etc.
All rights reserved.
RMT Engineering
Projects (page in progress)
This large Tesla Coil worked well, generating 16" arcs, but I can
tell that it could do better if I couple the primary closer to the
secondary.  I plan to work on that soon.  This is a great
demonstration for resonance as well as inductive and capacitive
reactance.
Here is a picture of a small briefcase Tesla Coil.  This
demonstrates the same effects as the large coil above, but is
much more easily transported.  Generates smaller arcs - about 7".
 I leave it dusty looking to enhance the "old and mysterious"
effect.  
This is an animatronic head project.  So far the eyes move in two
directions and the mouth moves a little. There are passive IR
sensors so it can respond when someone gets close.  I have a
speech module attached.  So when someone approaches, they
are detected, the eyes move in their direction, and he greets the
visitor.   The "brain" is an Atmel microcontroller.  This is a fun
platform to demonstrate servos, speech and microcontroller
programming.  Work is ongoing to fine tune this project.
Here is a view of a small bot.  The basic electronics have been
incorporated into the small board in the center.  It has an Atmel
microcontroller and TI motor control chip.  The PCB is an in-house
design.  In front are IR sensors for collision avoidance and feeler
sensors in case it bumps into something.  Small gearmotors are
under the white plastic base, hidden from view.  Also underneath
is the 7.2V battery pack.  We expect to use this bot as a platform
to develop more useful features.  One area that needs to be
developed is an easy way to connect a charger for the batteries.
Here is a picture of the microcontroller board used on the small
bot above.  This is a nice general purpose board designed here
using ExpressPCB CAD software.  The large chip is an Atmel
ATMega168 and the smaller chip is motor driver TI SN75441.
There is on board power regulation and provision for crystal if
needed later and for an LM386 audio amp chip.  The board is
designed to accommodate direct connection inputs from Sharp IR
proximity sensors, and direct outputs to servos. Small DC motors
are directly connected to the green connectors at lower left and
right.  DC power in is on the bottom edge. Programming is done
with the micro in circuit, through the 2X3 pin header.  Usual
practice is to program in BASIC using a BASCOM compiler.