Posts with «dorkbotpdx» label

(F)Light Suit Major Components

The main components of the (F)Light suit:
(Updated 8/15/11)
Component(s)SourceStatus
LED stripsDealExtreme 22 strips with connectors, need sealing and velcro backing.
8-channel MOSFET Output BoardsDorkbotPDX board orderThree built and tested, work perfectly
Arm accelerometers Modern Device Left one on main board, right attached with 3-wire lead across shoulders
Black flight suit Amazon Needs velcro for LED strips
Arduino-compatible main board: Minimalduino 105 DorkbotPDX board order
Arduino interface board: Adafruit protoshield Adafruit Industries Done, ready for mounting and cable threading. Ports for MOSFET output boards, right accelerometer, remote control, audio sensor
Remote control homemade, various parts Needs laser-cut acrylic surround, rot 2 flaky
Batteries eBay 12V, 4800mAh Li-ion battery packs with barrel connectors, powering third MOSFET board.
Audio input: ZX-Sound board RobotShop.com Test, add light, change connector, paint, velcro back
Missing anything?
Jeff's Arduino Blog 10 Aug 20:03
adafruit  dealextreme  dorkbotpdx  ebay  flight suit  lcd117  minimalduino  moderndevice  

(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.
Jeff's Arduino Blog 26 Jul 05:13
74hc595  dorkbotpdx  flight suit  pca9685  shiftpwm  

Minimalduino 105: Nice!

I built out one of the "V.105" boards I got a few weeks ago from the DorkbotPDX PCB order, and it works beautifully, almost identical to the version 107 I posted files of, with "5V/3.3V" voltage and "FTDI/IN" power selector switches. I mounted a mini USB socket and a 7805 regulator, in addition to the barrel jack for power in.

I've gone to whole number versioning btw, no need for "always under 1" versioning or major/minor versions, and if I need to go higher than 999 (huh?!), I can just use four digits.

Top and bottom labeling came out great, including the Open Hardware logo, though the letters mush together a little. Also, the "FTDI" header label didn't print at all, maybe there's a problem having two "FTDI" text labels.

One issue is that the drills for the main female headers are smaller than those on versions 89 and 97 boards, even though they use the same parts in EAGLE! I'll check the parts and maybe swap them out. That's a bummer-- I had to drill them all out to mount the headers, which ripped some of the pads off the fiberglass, but thankfully they stayed connected to the traces.

Minor edits for the next version:
  • Move the power input components to give electrolytic capacitors more room to accomodate shorter/fatter ones or taller ones mounted horizontally. As it is, the 100uF cap at the input is jammed between the .1uF cap and the barrel jack. [done]
  • Rotate LED's so they can be mounted horizontally for better side viewing when using a shield. [done]
  • Add heat sink polygon and vias under the 7805 tab.
  • Fix the Sparkfun mini USB through-hole part: its outline is on the bPlace layer, not tPlace where it belongs. Or just use a different part. [done]
  • Check female header drill diameters.
  • Add 2-pin header at the reset button to make it easier to add a remote panel-mounted reset button. [done]
  • Round the corners; looks nice on the Freetronics boards. Also check Uno outline and drills to make sure things are lined up right. [done]
I'm pretty happy with this for now though-- I have plenty of cheap, homemade, 5/3.3V-switchable Arduino-compatible boards to work with!
Jeff's Arduino Blog 15 Jun 20:34
arduino  dorkbotpdx  minimalduino  

Minimalduino v.105: Curvy Trace Fun

I've been trying out some Hope RFM12B radio modules-- very cool and inexpensive!-- which run off 3.3V. I've been using MinimalDuinos since they're 5V/3.3V switchable, and I got three version .97 boards made last year, with curvy traces, and they're coming in handy.

I have a few boards I'll need to get made over the next few months, so to warm back up with EAGLE, I polished up a straight (normal) trace version .105 board and set to curving it up. It took about an hour and a half, going around trace by trace in move mode, lots of command-clicking and dragging in the middle of trace segments to adjust their arcs. I submitted it to the DorkbotPDX PCB order before the deadline hit, and I can't wait to see what I get :) Design files and snapshots can be found here.

A key goal of the design is to have a good single-sided pattern for home etching, so I'll also make one by hand after fattening up as many traces as possible.

V.105 with straight traces:

Compare to V.105C, with curvy traces:
Jeff's Arduino Blog 09 May 16:59
dorkbotpdx  eagle  minimalduino