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First Steps: State of the Union

Doug Leppard (DLeppard@CCCI.Org )
Benjamin Leppard (Benjamin@Leppard.Com)

Author’s note:

This is the forth  in a series of articles outlining the steps we have taken to build our robot. Both Benjamin and I are newbies
at this and thus this article will be written for newbies. These articles are focused on a robot that will compete in the Fire
Fighting contest
, be able to roam around the house and will be a fun learning tool. The 68HC912B32 is our processor, so
articles will be on interfacing to the B32 to various mechanical devices and sensors using SBasic as our programming language.

Previous articles:

"Setting the Stage for Building a Robot," we set goals for the robot and did research. From the goals and
research we will make fundamental decisions on what our robot will be like.

"Choosing the CPU, Language and Basic Shape," using our goals we choose what microprocessor, language and what the fundamental shape of the robot.

"Motorola’s S-Record" looking at the S-Record format the Motorola uses to load data and programs.

"Booting up the 68HC912B32 for the first time" goes into detail how to boot the B32 up and run a program.

State of the union

My previous article deals with booting up the B32 (68HC912B32) was written in January 99 but did not come out until June 99.  I decided to give a pictorial overview of the state my robot.  From that you can see where I am headed.  Then the following articles in the months to come will go into detail on each subsystem of the robot.

Robot overview

To the right is the front view of my robot and I have decided to call Onesimus.  The computer I built from scratch in 1976 I also called Onesimus.   Onesimus is taken from the Bible in Philemon 1:10-11 "...Onesimus ...Formerly he was useless to you, but now he has become useful both to you and to me."  That was symbolic my first computer and now my robot.  The computer was formerly useless when I first built it, now look at what computers can do.  My robot is also useless and people "Ask what does it do and why did you build it?"  For now I build it for the joy of building it, but who knows where this will lead.

Onesimus is built with three levels.  The lowest level holds the motors, batteries and the motor H-bridge controllers.

The middle level holds the various electronics including the B32 micro.

The top level holds most of the sensors and the servos for the sensor pod (head).

robotfront.jpg (48013 bytes)
This is the side back view of the robot.  As you can see, each level is made of plywood, which is easy to cut and drill which makes it easy to mount things on it.

The rest of the article will deal with each section and what sub-systems are in that section.

In future months, I will write articles going into detail the various sub-systems.

robotback.jpg (52930 bytes)

To make it so this page will load faster, I have put each section on its own page.

Lower section: wheels, motors, batteries, motor controller, and wheel encoders.

Middle section: B32, electronic compass, beeper, switches, connectors and misc. logic.

Upper section: sonars, servos, voice board and heat sensor.