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Larry Barello


Late spring 1999, I turn my attention to building a fire fighting robot. I entered it into  the Seattle Robotics 1999 Robothon Fire Fighting Competition and took second place.  This is a work in progress. Preliminary software has been completed.

Current Hardware Configuration:

Software Status

Future Stuff:

The Engineering problems:

Picture Gallery

Back Quarter View

Front Quarter View

Side View

Here are three views of Dilbert.  The paper horn was placed on the fan to direct the airflow in a more concentrated pattern and to cover a larger vertical distance. 

Partial Disassembly

This view is with the top panel and the drive wheels removed.  You can see the encoders and the Hitec 605BB servos.  The aluminum plate was cut out on a band saw, turned on a lathe and the wheel slots cut with a jig saw.

Circuit Board

The L293 motor driver chip is to the far left. A hex inverter is next followed by the AVR 90S8515 controller. The far right is the 5v regulator, conveniently located under a mounting post. The connector next to it is for the LCD display The connectors on the upper left are for the Sharp proximity detectors, On the right are the SPI and serial interface headers.

Encoder wheel

I crafted an encoder wheel using a drafting program, printed them out on my laser printer and glued them onto 4" disks of Plexiglas that served as the wheels.  The wheels also have 4" silicon O-Rings as the tread.

Drive Wheel Assembly

The Hitec HS-605BB servos are stripped of electronics, the tab clipped to allow continuous rotation and have an 4" wheel (4" silicone rubber O ring) attached to the original control "horn" that came with the servo.

Encoder Electronics

Dilbert has two Hamamatsu photo reflexive detectors set up 90 deg out of phase for quadrature detection. The encoder has 45 segments, which gives the robot 180 clicks/revolution, or 2 deg, or 1/15" with a 4" wheel.

Floor sensor Assembly

Floor Sensor

GP2D02 Sensor assembly

User Interface

LCD with data display

Code base

As of 7/7/99, for the IAR v1.4 assembler: firebot.zip