First Experiences with Parallax Board of Education

LED blinker

I'm now taking an Intro to Engineering course at Virginia Western Community College.  As part of this course, students divide into teams of 3-4 and build a robot to perform in a modified ASEE robotics competition.  (I'd like to note that my experience in VEX and FIRST has already helped me significantly in this class.)  Each team is loaned a Parallax Board of Education (BOE) kit with the BASIC Stamp 2 (BS2).  This is a review of my first experiences with the BOE-Bot.

Overall, everything was easy to get set up.  The online documentation for the BOE-Bot is easy to access and descriptive.  Installation of the official software was simple and fast.  Actually, while the software installed, I got the first example circuit set up.  This the picture on the right--a simple LED circuit.  One LED is connected to each I/O 12 and 13.  After playing with this circuit for a bit (practice looping, pulse out commands, etc.), I went on to build the standard robot.

(Almost) Complete BOE-Bot Base

This robot uses a pre-built aluminum chassis and very few other parts, so the actual weight of the robot is much less than a comparable NXT or VEX robot.

It uses two continuous-rotation servos for the drive.  Right now, I don't have any sensors on it, but I have a couple IR LEDs and receivers for a primitive distance sensor.  It also comes with a set of "whisker"-style touch-bumpers.

Programming the BOE-Bot should be easy for anyone familiar with the BASIC family of languages (especially the older ones, i.e. QBASIC).  I will say that it is much more bare-bones than other languages I've used, for example, ROBOTC.  Instead of just sending the motors a command to spin at a certain power level, I have to manually give the pulseout commands to the servos. 

I do have two concerns, which will be interesting to follow over the semester: speed of included motors, and 16-bit architecture.

Speed of motors isn't a really big issue--I can just get some other types.  It's only a problem due to the limited budget we have for the class competition; a set of two motors and controllers would take a large portion of that.  The included motors spin at a maximum of about 50rpm.  For comparison, VEX motors have a max speed of 100rpm or 160rpm, depending on the motor.

16-bit variables are a bit more of an issue.  I'm used to the 32-bit NXT or VEX Cortex, so watching for overflow at numbers just over 65000 as opposed to over 4.2x10^9 is a bit challenging.

All in all, the BOE seems to be a very user-friendly robot.  Approximately 4.5 hours after starting work, I now have a robot that drives back/forth and turns.  I'm looking forward to a great semester project.