L3: The Expressive Rolly-bot


Thomas, Krithin, Amy, Daniel, Jonathan

Group Number:


We originally built an automaton that used two wheels powered by two DC-motors. The wheels were thick, sturdy paper plates large enough to fit the Arduino and batteries snugly in between, like a sandwich. Unfortunately, after many attempts and tweaks we were unable to make it successfully work, and scrapped it for a smaller, simpler design using two halves of a yo-yo. The Arduino and batteries were removed from the robot itself and were attached via alligator clips.
We wanted it to move really fast and considered small paper plates an effective method. Alas, they weren’t; the yo-yo wheels were better. It rolled around quite nicely and we like that it is basically a segway without a steering pole, it goes on its own with just two wheels. Attaching the plates directly to the DC motors didn’t work, so we attempted attaching bottlecaps to the motors, and then the plates to the bottlecaps. That didn’t work either so we switched to a yo-yo.
Brainstormed Ideas:
  1. Spinning Screw
  2. Mechanical Bird
  3. Grappling Velcro Hook – uses the Velcro arm to pull itself
  4. Quad-copter
  5. Wobbly-walker – Two-armed “crawler” that has two parallel arms offset by 180 degrees rotating together.
  6. Balloon as Bellows – a motor controls a valve to release air from a balloon to propel it
  7. Submarine
  8. Unicycle
  9. Growing Seed – a seed planted beneath a robot, the motor waters the seed, as it grows it will move the robot skyward
  10. Ripstick
  11. AT-AT – a four-legged spider-walker
  12. Car – either a two-wheel or four-wheel variation
Photos of Design Sketches AND Video of Final System:
Kaltura media memory limit reached, so here’s a link to all of our pictures and videos, captions are provided there as well.
Parts List:
  • Arduino
  • AA Batteries (4)
  • DC Motors (2)
  • Yo-yo (1)
  • Stackable Pin Header (3)
  • Sticky Putty
  • Electrical tape
Instructions for Recreation:
  1. Tape two DC motors together, so the spindles are facing away from each other.
  2. Place the three pin headers around the two motors, like a splint, to keep them aligned. Duct tape it all together.
  3. Wire the motors to the Arduino (motors are wired in parallel to the 5V and Ground pins) and wire the Arduino to the batteries.
  4. Stick putty inside the yo-yo halves.
  5. Attach yo-yo halves to DC motor spindles.
  6. Plug in batteries and watch it go!

Source Code:

No code was used, we just used the Arduino to connect the motors to the battery source; no code required.