Wiring it up to a boarduino is not as easy as simply plug&play as with an Arduino, so you’ll need a few wires. Still its very straightforward!

when you power it up it will immediately start doing its thing which is fading thru some nice colors

But the real fun is programming it…upload the Arduino Communicator sketch and then run the blink Sequencer on your computer. Connect and then select which colors to display

2 years ago when I worked on Duel Nature, I made a table of data that approximates a heartbeat. I couldnt quite duplicate it directly because the loop time is 3 seconds not 1 second, but I didn’t do too bad. Here it is in ‘autoplay’ mode with the heartbeat script. Sadly it doesnt seem like you can save the script to share it.

Click To Play

Add a coin cell, and you’ve got a ValenThrowieM (Valentine LED Throwie M)!

Click To Play

Next I wanted to experiment with talking to the BlinkM over i2c. I decided to make a little temperature display. When its cold, the LED turns blue, when its hot it turns red. For the sensor I simply used a LM34 which is super simple: just give it 5V and ground and the middle pin will be at +10mV/degF. So 68 degrees is 680mV.

I used a little heatshrink to protect the wires:

Then wrote a sketch to tell the LED to change color, here it is at room temperature

(65deg, its cold in here)

Squeezing the sensor brings up the temp a bit, to maybe 85 degrees, a little pinker

Then some icey water (its in a plastic bag to protect both the sensor and my drink!)

and some hot tea

The final analysis?
The BlinkM worked well and is a nifty little thing, the Sequencer software could be improved (can’t save scripts, cant adjust loopspeed, clicking on a ‘frame’ doesnt display the RGB value…) but its impressive that theres any software at all. It seems like the real control comes from sending it direct i2c commands, so one would have to write a custom Arduino sketch to make it do what you want. (Or, probably better yet, a python script that talks to the Arduino communicator since at least then you’re not uploading sketches) While its not the right thing for people who want to make 100-LED blinky projects (since its ~$12 each), its probably a good accessory for someone with an Arduino who just needs a few lights for a standalone project. I could see them being popular as integrated into wearables/fashion technology. They’re hella bright too!

ps. I’d like to see someone show how to control them directly using a motherboard i2c port such as the ones that have temp (and sometimes IR) sensors.

I used a MIDIsense instead of a simple voltage divider because I want to extract the absolute LED brightness pattern and a photocell voltage divider acts ‘inversely’ (well, 1/R) instead of linearly (ie, just R). (The MIDIsense has an opamp to linearize the resistive sensor output)

There it is! There is a bit of ‘noise’ on the peaks because I’m picking up some of the PWM artifacts through the diffused white plastic.

OK so boards came in, and there’s 80-100 to be assembled. They’re pretty simple boards: 1 8-pin micro, 3 resistors, 1 capacitor and 2 4-pin header plugs. Since it takes a long time to solder, I designed the board for mass-manufacture: surface mount parts!

Eventually everyone needs to make a lot of PCBs (at home), the best way to do this is to use solder paste and a reflow oven. Since EYEBEAM has a laser cutter I can use it to make a screening stencil and a registration frame. (You can also buy stencils from your 4pcb.com and probably a bunch of other PCB manufacturers) Then it’s super fast to make tons of PCBs. Just silkscreen on solder paste (available at digikey), place the components, and bake!

***

First, cut out a frame from 1/16″ acrylic the same size as the PCB, this will be the registration frame

The PCB should be a perfect fit

Extract the stencil info. I took the stop layer, viewed it in GC-prevue, printed it to a file (ie. PostScript), then opened it in CorelDraw which is set up to print directly to the lasercutter

Cut it out in 2-3 mil Mylar

Register (align) the screen on the frame and tape it down

Now…use a biz card or something similar as a squeegee. Lay down a bead of tasty solder paste…
[gv data="http://video.google.com/googleplayer.swf?docId=6066848196815777770&hl=en"][/gv]

OK now you have a board with solder paste dots

Place the components with your tweezers
[gv data="http://video.google.com/googleplayer.swf?docId=-1907760876743714269&hl=en"][/gv]

Repeat 80 times, and put them into the toaster. 200 degrees for 4 minutes, 300 for 2 and then 450 until the paste melts, then 300 for a minute to cooldown.

Yay you are done! now all thats left is the thru hole parts…

There’s also a white silkscreen square to write an address to identify each PCB (since they’re addressable)

Then I checked the gerbers with GC Prevue and sent them off to 4PCB.com tuesday afternoon. With 2 day turn and overnight shipping that means they arrive Friday. Since it’s Kate’s first order with them, she gets $500 off the order… Basically we pay for shipping ($50).
Tomorrow I have to solder up 80 Duel Nature PCBs (maybe try out making silkscreens on the lasercutter)

(Starting the project…)

Kate came to me with these drawings and her original plan: the red LEDs would form a ’4-chase’ sequence. The budget is around $500 for all electronic parts, including LEDs, wiring, power, batteries, tools, etc. I decided to push the project a little futher: instead of a simple chase (which was well within reason), we would have each LED be individually controlled and PWM’d so that complex designs could be realized.
The biggest constraint (apart from the budget) is that all the electronics must fit in the square wing-support tube: .8″x.8″ and any wiring and connectors have to fit through a .5″ hole that was already drilled in the wings.

As always, I specified the connector first. Because of the small space, I couldn’t go with a feed-thru connector, and originally I wanted to use phone/cat5 cable and connectors but they wouldnt fit either. So in the end I was forced to go with 4-pin 0.1″ Molex MTA. It’s not the best but it’s dirt cheap and I’ve worked with it before. The connector pins pass power (3-5V), ground, data receive & clock. I decided against i2c and stuck with SPI because I’ve had good luck with it. It’s also more reliable than serial because of the clock.

To control the LEDs I picked the ATtiny13, which ends up being 75 cents each at the quantities I’m dealing with. It’s an 8 pin device: 2 pins for power, one for reset, and three for LEDs. The PWM code is written in C and uploaded to the chip using a surface-mount IC clip.