Let's Make Robots!


I dismantled a cd drive from my old laptop yesterday, and found out that the plastic frame and insides were a pretty good chassis for a robot. It will have an LCD screen, use an IR sensor for not running into walls, and possibly some odds and ends here and there. Does anyone have any suggestions for some of the features that would be integrated into this robot? I am using a Picaxe 28x1.


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Locomotion: What will you use to move it around?

  • Two gearmotors with differential drive will take up two digital outputs each from your 28x1.
  • Two continuous rotation servos (either hacked by you or purchased already made for continuous) will provide differential drive and use only one digital output each.
  • Note that I (and others) have had some trouble with the servo commands on the 28x1. If you try to disable the servo by setting the pin low (or high), it resets the Picaxe on at least some of the revisions. This seems to have been fixed on the 28x2. I thought it was worth mentioning.

Sensors: How will it see?

  • Will your IR sensor be on a servo so that it can scan?
  • You can also use multiple IR sensors and mount them at angles.
  • Consider supplementing the IR sensor(s) with bump switches or other sensors.
  • Do you want features like cliff detection so it won't fall off a table?
  • How about line following?

Thanks for your suggestions. The IR should probably be controlled by a servo, because otherwise I would need servos for the drive train. Are there any specific sensors that anyone would suggest? Should I replace the IR with an SRF05?

see differently. They both have their strengths and weaknesses. IR has a problem with black. Ultrasound has problems with narrower round objects and I believe fuzzy(?) objects. IR has definite distance ranges that are typically in 10's of inches. Ultrasound, I believe, is usually capable of measuring many feet. If you have the available pins, bump sensors can be useful when you are too close to something to be sensed by either of the other two sensors.

Are there any downsides to using IR sensors outside in the sun? And does anyone know of a cheap, tiny camera that would fit into the cd drive robot? I was thinking about using this one, but I would have to minimize the camera by taking it apart. The opening in the drive is only 1 cm thick.