making waves with the jelly

[ongoing news + progress]

so it's sunday night and the time is right. the last week has been well spent fabbing, circuiting, and hair-pulling. here's the update:

materials

• ATmega16
  
• IR transceiver
  
• clear acrylic base corel file dxf: this has a series of holes cut into it to attach (via pretty ribbon) the motors, the fabric for the body, and hooks for hanging
  
• fabric for the body: shimmery ivory organza and iridescent purple/pink/blue (it matches the violet LEDs!) georgette
  
• ribbons + string: pinky and beigy (visceral colors) kinky ribbon for the inner parts, and silk cord for tentacles, and ties for the motors and fans
  
• fans: huge $14.99 case fans from microcenter, each of which outputs 72 cubic feet per minute. WHOA. i have four of them.
  
• motors: ten stepper motors to twitch. i might have killed one of them already. details follow.
  
• lots and lots of mosfets.
  getting a little current-crazy.
• acrylic pulleys: lasercut components in which to tie the tentacles onto the motors
  
• thin copper wire: to sew LEDs into the fabric
  
• LEDs: violet for sparkle, bright-white for illumination
  
• ELwire + inverter from coolight: still pending. but pink tail wire + white 2.3mm wire to string along tentacles
  
• some sort of stand: thinking along the lines of a suspended birdcage. second best thing: a wheeley portable wardrobe.
  
• circuit [prototype as of now]: schematic, board, gerber
  

what works

• circuit: so i fleshed out a quasi-realistic schematic for the board. a little (well, super) tricky to route, so just breadboarding at this time until the circuit fleshes out completely. havent decided whether to modella it or etch, but the board seems like it'll be really big. planning on using the ATmega16 chip, with 32 glorious pins to work with. the basic organization is PORTA -> IR transceiver to detect proximity, PORTB -> fans, PORTC -> motors, PORTD -> LEDs.
  
• AVR: right now, testing on the AT90S8515 chip with the STK500!!! unsurprisingly, coding in C has been a godsend. using winAVR with programmer's notepad + avr studio. a little tricky + finicky; lots of late nights spent head-scratching, thanks to drained batteries, defective alligator clips, a wayward LED, and software crashes.
  
• proximity sensing: played around witih IR transceiver, and know how it's working. very cool.
  
• body: initial attempts using four small case fans were paltry, sad, flaccid. the fabric's a bit sheer and porous, but the fans failed to make it budge. basically, they blew [pun intended]. scavenged microcenter for some mightier fans. definitely hit the jackpot with these super ones that even come with their own modulation knob. tied them up prettily in bows with silk cord and strapped them, damsel-to-traintracks-esque, to the base. good news: got PWM working on the fans to adjust the speed. managed to hook (n+1) fans up so they coordinate and spin synchronously. each fan (12V, 0.5 amp per) is attached to its own mosfet to maximize the wind output.
  
• tentacles: got stepper motor to work, but then it started to flip out and get warm + stop working + twitch. the motors are tied to the underside of the base, and tentacles are tied onto lasercut pulley-hooks on the motor. as the motors pulse on and off, the impulse wiggles down the attached string. each motor has its own mosfet, though all of their motions are coordinated, so all assigned to identical pin.
  

below, the four fans installed onto the base. the fabric PWM-poofs!


what will work

• interactivity: havent hooked up the IR transceiver to the circuitry yet,
  but i have parts working on breadboard. when a person gets close/touching, the lights will flicker, the white lights will refresh illumination, and the body + legs will convulse.
  
• coordination: getting the timing right so that motors, fans, and lights work together simultaneously.
  
• the LEDs: the LEDs will be distributed about the fabric body, sewn using copper wire as thread.
  
• suspension: jellyfish will be hung with clear fishing line [how appropriate!] from some sort of hook. first thought was a freestanding doorjamb-like thing, but a birdcage will work nicely. trying to find one, or will fabricate a good solution.