Saturday, May 11, 2013

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.

Sunday, January 20, 2013

Atari 2600 Hackback?

I've had a clean 1980 Atari VCS CX2600A for a dozen years or so, with joysticks, paddles, power brick, and cartridges, but the video output was always terrible, and I couldn't get any useful image out for a few years.

I followed (one of) Ben Heck's instructions on getting composite video out, but while everything checks out circuit-wise, and I get some video output, it was dirty and I couldn't stabilize it. Not a surprise since it wasn't working well to begin with!

Reading about the Flashback 2 from a few years ago, it turns out there's a way to add a cartridge port to it for playing old games. Instead of turning the Flashback into something even smaller, I wonder about going the other way: transplanting the Flashback 2 into the original 4-switch VCS, using as much original hardware as possible. It doesn't look like anybody has gone in this direction, but thankfully the VCS is well documented online; even the original service manual in PDF.

"Atari Hackback" seems like an appropriate project name. Thanks to Craigslist, it took a day to find a clean Flashback 2, and this handy reference shows where the cartridge pins go. There are a LOT of signals to reroute, but I'd like to preserve the hardware's connection to the PCB, so will need to find other solder points for attaching leads.

Monday, January 7, 2013

Too Many Parts... TGIMBOEJ!

I have a tendency to over-order, whether at a restaurant or Fry's or Mouser or Adafruit, and I find myself with an excess of parts and other electronic junk. Some parts were destined for a project that took another turn, or I ordered parts to build two copies and only built one, or I raided a kit for a few parts and filed the rest away. I'm also a sucker for the free and cheap and just enjoy tearing down gear for motors, IC's, power parts and of course blinkable bits, always adding to the parts stores.

But some bins are filled to bursting, and I have more parts than I will use: time to pass this stuff along. Enter TGIMBOEJ: The Great Internet Migratory Box Of Electronics Junk: fill a box with stuff and send it to a stranger! The website hasn't had much action lately, but the request list is long, but I got in touch with somebody still interested. I'm hoping to send a box of tomorrow or Wednesday.

Note: new "NAR" tag added for "Not Arduino-Related" posts.

Spreadsheet Updates...

I've found more Arduino-compatible boards ('328- and '32u4-based) to add to the spreadsheet... there are always more! Plus I need to add the new official Arduinos, so: I have mixed feelings about Arduino hardware. Their official boards have diversified in odd directions, and non-official versions keep doing everything better. For instance, it's strange that with so much going on on a Leonardo board, there's still no 3.3V/5V switch or jumper.