Thursday, 21 September 2017
The Braitenberg Vehicles are done and today we demo’d them as a group. The bots show varied chassis styles, though the electronics are functionally the same:
We learned to breadboard! Super cool experience that I’m sure will pay off later as we develop our own projects.
We learned about basic circuit components! Resistors, photoresistors, jumper wires, transistors, and diodes are all in our wheelhouses now.
We learned how motors work! Swapping the connection results in a backwards-spinning motor. So cool!
We strengthened troubleshooting skills! Man, those breadboard holes are close together. You wouldn’t believe how often that messed us up.
I only managed to record one bot during demo time — this guy runs from the light, which Braitenberg dubbed “Fear”:
Note to self for next year:
- Consider the ways that a cardboard box can be a structurally sound chassis and show the kids some of those methods. A flat piece of cardboard is iffy at best and electrical tape is way too stretchy.
- Locate a room that can be made quite dark. The classroom is way too bright to get the bots to turn toward a flashlight spot. For quick tests, it’s important to have a space.
- Invest in a few flashlights whose beams can be focused better than the ones I have. A broad beam tends to hit both photoresistors and the bot doesn’t turn (though fixing that problem is a fun design challenge, too, so maybe not). One student was driving his bot with a laser at the demo — does that method have long-term benefits worth investigating?
- Is it possible to use the same motors that come in the Ardumoto Shield Kit? They’ll be central to our line follower bot for the next project, so it’d be nice to reuse more materials to save costs and keep with familiar parts.
- Do I want to organize demo day in a more rigorous format? I had the kids share with another person, then we drove our vehicles around a dark-ish room for awhile and had fun reveling in the finished project, and finally we reflected on the experience.
EDIT: Parts List
- 2 Solarbotics geared motors with wheels
- 1 breadboard
- 2 NPN transistors
- 2 photoresistors
- 2 diodes
- assorted jumper and breadboard wires
- 9 volt battery and a battery connector
Circuit diagram and explanation of how it works.