Meeting Minutes 2007.06.26

Hoodies and patches are here!

To do for Fourth of Juplaya

One Orb

Thursday 5:30pm Welding

Saturday and Sunday work day at shop.

1. Schedule on Playa

• Mike and John: Monday - Thursday
• Niladri: Tue - Wed
• Tad: maybe
• Post to List

2. Power

• Niladri can get a generator for 4th
  • Will drop off generator to Mike since they are leaving earlier
• Ideal to charge batteries inside orb. Impliment diode.
  • Lee thinks should work

3. Aluminum orb?

• Entire inside welded on one half. Some outside welds on smaller ribs.
• Other half ground and ready to weld.
• Thursday to weld. Lee will be there all day. Chris later: 5:30ish.
  • Need two people for alignment. Larger slots make it harder.
  • Respirators needed? Whatever makes you comfy.
    • Aluminum not as bad as stainless (ala Erin Brockovich and Zodiac), don't breathe the smoke.
    • Aluminum does not cause parkinson's.
    • TIG welding produces the least amount of toxins. Yay Green!
  • If just weld one side (inside) may be a concern for stress.
    • Maybe just do 16th inch filler rod on outside if heavy inside.
• Bucket Handle, 1/2 inch steel or aluminum tube. More about stiffness than strength: Steel
  • Need 4 pieces of about 10-20ft. Probably 20 feet. 2.5ft/piece. Who is going to pick it up?
  • Bay Area Iron Works Supplier in Bayview. Allied Iron - Belmont (nicer than Alan Steel)
  • Round tube probably looks nicer maybe? Could use square (easier to lay stuff on?) Mike envisions round.
  • What if it goes up and over?
    • Can we weld it to C-clamps for break away?
      • What about wiring? (Throw away)
      • Threading issues
    • Keep bucket handle more flexible? Conform with sphere?
    • Single bar vs. multiple bars?
      • Don't want to bend & unbend with single bar.
    • What about rolling protection for electronics?
      • Bottom layer is steel.
      • Top 1/4 inch Polycarbonate dome etc.
    • Failure Mode:
      • Side to side or front / back forces
      • Destroy electronics
      • We're just speculating.

4. Computer Architecture Geek Stuff

• Johnathon will have laptop
• Dust proof
• Zigbee to outside
• On Orb GPS testing
  • Aggregator board running. Wired for straight serial out.
  • Bucket Handle (see above)
  • GPS data from Mother Node
    • GPS to Mothernode, some sort of logging thing to RF
      • (Michael's diagram) Jonathan thinks it's two lines of code.
      • Need IMUs (Tad ordered them - gave one to Jonathan (Tad showed up later))
      • Housing and wires, great if we can get it done. Depends on aggregator board.
• Daughter boards. Have three made. ($120 for 3)
  • Basically working, but haven't plugged in a lot of stuff.
    • A few bugs: Resistor, short
  • Heat gunning process (side discussion of toaster ovens, griddles, etc)
    • Solder on pads, no paste, then heat gun.
    • Tad has coworker who may be able to do some precise stuff for a reasonable price.
      • Conner likes doing boards. Maybe not have tools for really fine stuff.
• ISP Header vs 640 (Tad and Niladri)

GPS Discussion

• Hoping for firmware revision
• e-mail to Nathan, Matthew at eTek (no repsonse)
• 2 modules from sparkfun
  • Fallback options: RTCM Surfstar 2 (read their approach?)
• Rick has beacon. Getting more modules soon.
• MTK is totally different chipset (new)
  • Missing command set.
• Snooping mini GPS commands
  • Microsoft port monitor utility (MS website - portmon)
  • Linux/MacOS to sniff serial port? Fifo? named pipe.

More SPU discussion

• Jonathan has not ordered all of the connectors
  • Tad has good stock of CPCs and Dsubs and crimp tools
  • Old keyboard PS2 cables...female connectors, gasket through H-bridge etc.
    • Matt has a lot (also some 10-pin cable)
  • Digikey parts list is nifty.
  • IDC connectors for daughterboard? Just solder?
• Serial passthrough
• Can we spit to log file?
  • Easier on Mother node, 'cause file is there and don't need to extract
  • No preservation/evacuation mechanism
  • Can keep it on SPU (limit to loop over?)
    • Matt will look into that.
  • Dillo doing daemonizing
  • Niladri zigbee parser
  • Jonathon motor controller parser - status value out
  • Motherboard 10hz loop
• Kill switch? one free pin
  • Now: Edge triggered interupt - reports to SPU
    • Should be able to test. Mike feels better hitting enable on the H-bridge vs active brake.
    • Push/Pull, momentary resets. Variety of approaches.
      • Expose pin to toggle switch.

Main Event

Power

• Lee is working on Solar (6kw hours...)
• DPW Depot that Lisa may be able to access
• Maybe rent generator

Weather

• Swarm protection for rain?
  • Everything is sealed, trying to make weather/playa proof
  • But, don't want to expose too much to elements if possible.
    • Covered with tarps or ponchos most of the time for rain/dust.
      • But we want them to be visible.
    • Electronics with dome
    • Bearings, Gears, Chain
    • Battery connections fine (or goop with silicone)

Random stuff

Lee has credit cards to charge stuff on if you want to buy anything for Swarm.

Involved discussion of shipping costs.

Effects of welding Stainless Steel - effect strength, rust?

• Crystal structure - strength
• Alloy - properties
  • We'll store inside.

Tad is missing a component.