AVR-Chat

On Tue, Feb 03, 2004 at 12:06:26AM -0500, Dave VanHorn wrote:

> Tonights test gives 33 lines/sec print speed, roughly 1.5x the
> competition's top of the line machine..

Sounds very cool!  My application is nothing so time critical - it is
part of the operator interface for a robot rover.  On the operator
side sits a radio modem, MAVRIC-II, and Sony PS/2 controller.  On the
robot sits the other radio modem.  I've used the second serial port on
the MAVRIC-II to act as a pass-thru so that I can hook up a laptop for
a command interface.  When that is not in use, I have the game
controller to send commands to control various aspects of the robot.

On the robot I've got another MAVRIC-II and am using the on-board
RS-485 interface to control a pair of dual h-bridge motor controllers.
I had these made which incorporate an ATmega8 w/RS-485 which drives a
pair of LMD18200's.  The Mega8 generates the PWM, senses the encoders,
motor current, and thermal shutdown of each of the h-bridges.  I also
implemented a built-in PID algorithm on the controllers to maintain
constant velocity so it is set and forget.  Communication between
these smart motor controllers and the MAVRIC-II is with a packet
protocol over the RS-485 bus.

So the MAVRIC-II on the robot is free to control other stuff.  I'm
currently working on collision avoidance sensors (combination of bump,
IR, and motor stall detection) and a pan/tilt camera mount for remote
video.

The base is powerful - I need to be careful because it is strong
enough to push heavy object aside with ease, climb over anything it's
tires can get a grip on, damage walls, furniture, etc.  I'm intending
it to mostly live outside.

-Brian
-- 
Brian Dean, bsd@bdmicro.com
BDMICRO - Maker of the MAVRIC ATmega128 Dev Board
http://www.bdmicro.com/