Meeting Minutes 2007.01.07

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The proposal is due February 15th. It would be good to have a prototype to show BM by this time.

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Mike out of town Monday-Thursday. Weekend not ideal for meetings. Olya has class Monday and Wednesday evening.

Next Meeting Tuesday, January 16th. 8pm, probably Mike's place.


Currently Evaluating [ET301 SiRF III Evaluation Board], just GPS module available from SparkFun for $59.95

Looking at 3 axis accelerometer, possible 2 axis yaw rate gyros


  • 802.11a - poor range, good bandwidth, questionable tolerance of motion
  • Bluetooth - lower bandwidth, [sparkfun claims 100m range]
  • Antenna - can it be integrated in metal body? will it work through metal frame?
  • other technologies?

Computation Platform:

  • Want Floating Point
  • AVR with FPU?
  • ARM and PPC?
  • power efficient i386?


  • Steel rod
  • aluminum tube
  • sheet metal with plasma cut holes (available large enough?)
  • clear plastic (polycarbonate, acrylic)
  • recycled grocery bags (polyethylene?)
  • fiberglass


  • current prototype 2.5 ft diameter
  • larger diameter would give a more significant impression, maybe 4 feet
  • taller than bicycles makes them more visible
  • have to tradeoff weight, shipping constraints, cost, power

LED Options:

  • illuminate entire sphere or a few regions in one color each
  • make straight line persistence of vision array which forms images while sphere is moving forward
  • make rotating display attached to outer shell which forms circular display as ball spins

Audio Options:

  • Mechanical noise makers
  • Bleepy R2D2 noises, simple synthesis with midi tracks
  • sampled sounds, in memory with midi triggers. could be animal sounds, voice, instruments, etc.
  • streaming audio tracks with high bandwidth communications


  • Ultrasonic Sensors to detect and evade obstacles
  • IR sensors to seek humans

Mother ship :

  • GPS base station
  • central computer control
  • power generation

Green Man Ideas

  • Photovoltaics, built into mothership. Possible rent with insurance
  • pedal power generation
  • pedals drive mothership
  • power meter on mothership indicates proportion of Green Power.
  • power up at Illumination Village to avoid seperate generator
  • Green Man motif in sphere surface and mother ship
  • biomimetic behaviors (see below)


  • school of fish
  • ant swarm
  • bee swarm
  • flock of geese
  • dolphins and sharks
  • spheres change appearance - light, shape
  • ballet - involve choreographer
  • stand in line for cofee
  • vibrate to show emotion
  • mating behavior
  • different sized spheres with different roles- mother/child, warrior, drone, etc.
  • orrery - orbiting planets
  • sinuous smooth motion is important, avoid jerky motion
  • autonomous behavior - machine vision and learning
  • seek humans, solicit pedalers