Flight Suit V3

The next version of the LED Flight Suit marches forward with WM, lots of headway on key components:

• Three 16-channel, 12-bit pwm PCA9685 chips will operate MOSFET's to switch 48 LED strips.
• Small sot23 smd MOSFETs (or these); the old ones (P16NF06's) were too overkill, too big. Overkill is still good but there's some math this time.
• RC batteries for more power: peak 14.8V and 12A no problem, but will be <500mA most of the time.
• Thinner, lighter LED strips with 120 LED's/m.
• Arm-based remote control with a 1.3" OLED screen, dials/buttons/sliders/TBD.
• The remote control will hopefully be a second Arduino-based system, a serial peripheral to the main suit system.
• Multi-band audio analysis with MSGEQ7 or a separate Arduino FFT.

Most importantly WM is coding Arduino!  He already built a complete mode-switching, parameter-adjusting system with a figure diagram on-screen!  

We'll make the suits themselves-- the displays with LED strips-- when we have a working circuit and software: we don't know where everything's going yet.  So for a demo display I'm making a circuit board showing all 48 PCA9685 outputs on LED bars-- old school.  Here's the one I'm scrapping-- got too much rework:

and here's an MSGEQ7's output, from iphone audio, of seven values on a Sure Electronics 24x16 panel:

That display will also help when debugging and building the system.

(F)Light Suit Progress: PWM!

I had a frustrating time trying to get a PCA9685 working-- it wouldn't even reply with its register byte values. I've interfaced with other I²C chips and didn't expect problems, but trouble was all I got.

Poking around the Arduino Forum trying to find any examples with a PCA9685, I found the thread on Elco Jacobs' new ShiftPWM library to drive the outputs of the ubiquitous 74HC595 shift register with 8-bit PWM precision. His demo video is on the right. The example sketch was so straightforward, I had two chips driving-- and dimming-- 16 red LED's in minutes.

Once I saw those red LED's cycling, I considered that part of the project done-- thank you, Elco!-- and started laying out a driver board with a 74HC595, eight outputs hooked up to MOSFETs and test LED's, and screw terminals so they can be daisy chained. With the DorkbotPDX order deadline this morning, I had to stay up late laying it out and getting a final Eagle brd file ready, and hopefully it will work; I wasn't that excited about asking for six copies of a 3.9"x2.1" V001 design and having no time for a second run if they don't work, but... hey, they'll work!

Here's the Eagle schematic: pdf, sch. And the board: pdf, brd.

LED (F)Light Suit: Ramping Up

I've been mesmerized by bouncing red LED's since the early '80s. LED's were mostly red, needle-style VU meters were on the outs, we hadn't yet graduated to green-yellow-red meters, and I grew a special place in my heart for those bouncing red lights. We also had KITT and the Cylons: bouncing red lights were and still are awesome ("rad" had not been invented yet).

I put together a black flight suit with red EL-wire segments for Burning Man in 2008 but did not have time to build the sequencer and control system I envisioned, so it was an on/off affair, or it pulsated to the music before the small batteries died.

Working on a suit for this year's burn, I've decided to return to the original concept-- red LED's-- and am working on the major areas now:

• Suit electronics: Arduino core, I2C port expander w/PWM output using PCA9685 16-channel, 12-bit PWM I2C-bus LED controller driving power MOSFETs, one per segment. There are 17 segments in my design, so I'll use the port expander and then another spare pin to trigger the 17th channel.
• Audio metering: I have a MaceTech Shifty VU shield working but I wonder about adjusting levels on the fly, and how to best get a mic input to it or something similar. There will be other modes for sequencing the lights, but bouncing VU meter is the primary mode I'm looking for.
• Segment planning: location and length of each segment, power lead routing, attachment to suit. This is going well, with the first seven (of 22) segments cut and tested last night from my first 5M strip from DealExtreme; the suit will need 53' of light strip so I've ordered more.
• Power: rechargable 12V power packs are easy to get; not sure how to recharge them on the Playa.
• Remote control: would like to have a small, wireless remote to control modes and mode parameters.
• The program: I have a list of modes I'd like to switch between, some of which have parameters I'll want to adjust on the fly. Ideally I'll be able to edit the program during the day if I come up with new ideas while I'm in BRC.