Random experiments, circuits, code, rapid prototyping, sometimes things to buy, and the odd tune by Tod Kurt.
The various prototyping shields available for Arduino are a great, sturdy way to add a breadboard. The Boarduino is another nice way to securely attach an Arduino-like device to a breadboard. But if you already have an Arduino and a solderless breadboard, you can attach the two together with an amazing bit of open source technology called a rubber band.
It’s pretty friggen great.
On Nov 8th I was a guest lecturer at the “Theory and Practice of Tangible User Interfaces” class at UC Berkeley. It’s a physical computing course, about “a new approach to HCI which focuses on the physical interaction with computational media.” The class has both lecture and lab components. The lab section is hands-on experimenting with novel physical interfaces, using Arduino as the core. So of course I have a great fondness for the course.
The talk itself was a sort of summary of the things we’ve been pondering at ThingM. If you’re already familiar with the stuff Mike and I have been talking about for the last several months, there’s not much new. But for me it was interesting to put it all together into one package and attempt to construct a narrative that threads it all together. The talk covered:
Before my talk I got to see the in-progess work of the students’ final projects to create new kinds of musical instruments using a variety of input devices, Arduino, Processing, and so on. It was great. I was invited to be a guest lecturer by fellow Sketcher Kimiko Ryokai, an assistant professor at Berkeley’s School of Information. Thank you, Kimiko, for letting me be a part of your class and to meet your students. The class was 40 strong and it’s obvious there’s a lot of interest in the process of making software interact with the real world. I hope more schools follow in this one’s path.
The PDF of my slides with notes is here:
– berkeley_info290-13_todkurt.pdf (8.8MB PDF)
The Boarduino is an Arduino work-alike kit from Adafruit.com that’s smaller, cheaper, and you can build it yourself.
The Boarduino’s small footprint made me want to see how small of a device I could whip up in an hour from some fairly complex components. So I decided to see how small the combination of a Boarduino, a Wii Nunchuck, and a hobby servo motor could be. Here’s a little video of the result.
WineM solves the problem of remembering all the information about the wines in a large wine rack, cellar or cabinet, or searching through that data. This smart wine rack makes that information always accessible and updatable.
ThingM will be at Wired’s NextFest conference, showing off a prototype of our WineM product. Come visit us if you’re in LA!
You can even read a press release about WineM.
WineM has a bank of RGB LEDs for every cell a bottle can go in. Each cell has a microcontroller implementing a high-power variant of a SmartLED.
There are 576 total LEDs in the WineM prototype, controlled by 52 microcontrollers, bussed together over an I2C bus.
Here’s a little video showing the cell lights in action.
The electronics in each cell look like (click for more details):
Standard through-hole components were used since space wasn’t an issue.
Each cell also has an RFID antenna to recognize the RFID tags on the wine bottles. This lets you recognize which wine bottle is in which cell. A controller board holds the RFID reader and controls up to 12 cells. Four controllers are linked together to in the WineM prototype to control the entire rack:
The Parallax RFID reader is a pretty cool bit of tech. For $40 you get a reader with integrated antenna that outputs ASCII at 2400bps. Unfortunately, the integrated antenna means you can’t place RFID tag sensing in tight spaces. You can however circumvent the built-in antenna and add your own. With a remote antenna of your own creation, you can customize its size and shape to fit your application.
First, locate the two places where the circuitry connects to the
antenna. (click the images for larger versions with notes)
Then using an Exacto knife or similar device, scrape away the traces leading to the antenna. This disconnects the built-in antenna. Then scrape away some of the solder mask on each of the traces leading to the circuit and solder down some fine wire. I use wire-wrap wire.
The two wires soldered can then be led to a jack of some sort. I used a 2-pin Molex header I had laying around. Now you can fashion a remote antenna.
To fashion an antenna, you need to create a >1/2″ diameter loop of about 100 turns of 30-gauge enameled solid-core wire (aka “magnet wire”). Radio Shack sells a pack of magnet wire that fits the bill just fine. Wind the wire around something handy, then keep it together with clear fingernail polish. Use a lighter to remove the enamel and solder wires to it.
If you have an inductance meter, use it to make sure the inductance is between 500-1000 uH.
If the inductance isn’t high enough (i.e. not enough turns) the RFID reader just won’t work and you may even damage it. But then, if you’re taking an Exacto to your reader, you’re probably not so concerned about that.
Jed, aka “JedJedJed”, “Jedders”, “Jedbutt”, “Little Wacko” died today after living approximately 15 years. He died quietly in his home with me at his side.
Continue reading “In Memoriam: Jed the cat, ~1992 – 8 Aug 2007”
The Sketching in Hardware 2 conference was a blast. So many interesting people and ideas. I wish we could have it every few months. Mike has his notes and a good summary of this year’s Sketching.
My talk was on “Smart Interface Components”. It was a generalization of the things I’ve been thinking about with the Smart LED prototypes.
Slides from the talk: sketching07-tod-smartcomponents.pdf
What are Smart Interface Components? Current interface components, the sensors and actuators that comprise the user interface of the gadgets we use, are dumb. They require specialized domain-specific knowledge to make work correctly, non-trivial processing to use, and in general are a pain. Tiny microcontrollers are becoming cheap enough to embed even at the edges of our hardware designs. A component with local brain can embed some of the domain knowledge and enable a higher level of communication between it and the application processor.
An example presented is a Smart LED. LEDs are dumb. Multi-color LEDs are hard to control. Can we make it better?
Imagine an LED that instead of worrying about PWM and current-limiting resistors, you just give it the HSV or RGB color values via a serial line? “#FFCC22 @ 20% brightness”, you say.
Some prototypes (from the flickr set):
Work is continuing in making production versions of these smart LEDs.