Category Archives: Arduino

Hans and Umbach: WiiChuck Pong

Hans and Umbach recently had a huge breakthrough that they wanted to share with you. A few weeks ago they built the Monski Pong example from Tom Igoe’s Making Things Talk book, substituting a few potentiometers for the arms of their non-existent Monski monkey (and non-existent flex sensors). They learned a lot in the process, but the boys have become increasingly concerned that they haven’t done enough work with front-facing interactions.

Stuffing a few wires into a breadboard is great for proof-of-concept work, but it brings with it a delicate and fussy interaction environment that lacks robustness and aesthetics. In the last week they’ve refocused their efforts on interactive input methods, rather than raw electronics, taking apart a Super Nintendo controller and interfacing a Nintendo Wii Nunchuk in the process.

Hans and Umbach: Taking apart an SNES controller

Hans and Umbach: Taking apart an SNES controller

Hans and Umbach: Arduino Hearts Wii Nunchuck

This got them thinking. “If we can access the accelerometers of the Wii Nunchuk as an input source, can we use them to play our Pong game?” The answer is yes, and the boys want to show you how they did it.

Hans and Umbach: Wiichuck Pong Components

First up, you’ll need a Nintendo Wii Nunchuk. These things are sweet, as they carry both an X and Y axis accelerometer (as well as a couple of buttons) for less than $20. Hans hasn’t found any libraries yet that interface with the analog control up top, but these other inputs have been more than enough to keep Umbach busy.

You need access to the wires and pins inside the controller, but it would be an awful shame to cut that beautiful cable. Lucky for us, Tod Kurt has created the WiiChuck adapter, a simple tiny PCB that takes the pins from the Nunchuk plug and breaks them out into a standard 4-pin header. You can get a WiiChuck adapter at SparkFun for a measly $3.

The adapter doesn’t come with the pins to plug them into your Arduino, though, so you’ll want to get a row of break-away headers so you can cut off a 4-pin header for yourself. You need to solder those pins into place, so now you’re also in the market for a soldering iron and some solder as well. And some wire cutters for separating those break-away headers from their kin. Yeah, it takes quite a bit of stuff to get started. We’re lucky to have Umbach on our team, who carries with himself a bandolier full of tools and electronics wherever he goes.

The whole point of the WiiChuck adapter is to be able to plug your Nunchuk into your Arduino, so you can do magic stuff like communicate serially with your computer, or control other things plugged into your Arduino. When it comes to writing code and working with the software side, Tod Kurt put together a WiiChuck library that makes it pretty easy to interface between the Arduino and the Nunchuk without doing everything yourself. If you download the WiiChuck Demo zip file, you’ll get the library of functions for connecting to the Nunchuk, as well as a demo that shows it all (hopefully) working.

The demo is great and all, but the boys wanted to make it do something. They had recently built the pong example from Tom Igoe’s book, and were interested in controlling the paddles with the accelerometer inside the Nunchuk. There are two pieces of software at work here. The first is the Pong game itself, written in Processing, that accepts incoming serial data and moves the paddles based on that. The second is the sensor reader, written in Arduino, that takes incoming sensor data from the Arduino and converts it into a format that the Pong game understands.

To get it all to work, Hans made some changes to the Arduino sensor reader example, blending it with the code from the WiiChuck demo. That way, the Arduino would pull down and translate input from the Nunchuk’s accelerometers (and buttons) into a format compatible with the Pong game. The game itself required minimal modification, only modifying the minimum and maximum ranges for the paddle values to conform to the range of values produced by the accelerometers.

Hans and Umbach: Wiichuck Pong Game

Et voila! C’est magnifique! This video up top shows the fruits of our labor… tilting the Nunchuk up and down moves the right paddle, and tilting it left and right moves the left paddle. One button starts the game rollin’, and the other button resets the scores.

If you’re interested in trying it out for yourself, Hans and Umbach have packaged up all their code into a fine and handy zip file. Or, you can browse the individual files ici:

WiichuckPongReader.pde (Arduino)
nunchuck_funcs.h (Arduino library)
WiichuckPongGame.pde (Processing) (Everything zipped up)

Thanks, and happy hacking!

Hans and Umbach: Arduino Party!

Our good friend Lorelei needed some electronics help the other day, so Hans and Umbach invited her over for a fun-filled Arduino Party. She’s prototyping a force-sensing coaster that encourages people to drink plenty of water throughout the day, and the first step towards that goal is getting a force sensor to communicate with her Arduino.

She managed to pull an analog input from her FlexiForce pressure sensor and send it as a PWM output to an LED, but was still getting some terrible noise from the sensor. Umbach managed to dump it all to the serial monitor, and lo and behold, the Arduino was reporting readings that ranged from 0 – 1023 and everything in between!

Hans and Umbach: Arduino Party!

Hans dismantled the circuit and rebuilt it, taking the Cat Sat On The Mat example from Tom Igoe’s wonderful Making Things Talk book as inspiration. In adjusting the sensitivity of the output from the sensor he tried all sorts of different resistors, from 1K to 100K, before ultimately settling on a 15K resistor. Umbach wired up the circuit to the Arduino, ran it into the serial monitor on Lorelei’s computer, and whammo! Success! A clean, analog signal coming from the FlexiForce!

Hans and Umbach: The Completed Circuit

We had a lot of fun, and encourage the rest of ya’ll to throw your own Arduino parties! Just don’t try to combine them with fondue parties… electronics don’t mix well with boiling oil and cheese… then again, they might go well with a chocolate fondue, so don’t let us stop you!

Hans and Umbach: Tragedy!

We have some sad news to report on the Hans and Umbach side of things. Umbach was soldering the other day, putting together our second Arduino Proto Shield from Adafruit, when he burned himself pretty bad on his soldering iron. Don’t worry, he’s a healer!

You see, Umbach keeps his soldering iron to the left of himself when he’s working. The strong affordance of the soldering iron seems to indicate that you should hold it like a pen, but of course that is a ridiculous notion. The long metal end of the iron is about a million degrees, and it will burn your skin in an instant. You should hold it not like a pen, but further back, like a… not pen… or a paint brush… or something.

But then, even that is not entirely accurate. As you get more comfortable with soldering you realize, or at least Umbach has realized, that the iron is not the most important thing you wield in your hands. The iron merely heats up the area, and it does not require nearly the fine motor control as the solder itself. Indeed, the solder should be held in your dominant hand, so you can be as precise as possible with whatever parts you may be slagging in liquid metal.

Umbach was in his groove, grabbed his soldering iron in his left hand, and without thinking made to pass it to his right hand, as he would a pen. He grabbed it for only half a second, but it was enough to burn the back of his index finger and the inside of his middle finger.

There is a lesson here, and it’s not necessarily that Umbach was thoughtless, careless and stupid. As humans we are constantly filtering information, performing apparently routine tasks without deliberate thought. This is in much the same way that I am convinced no one actually learns Photoshop or Illustrator, but over time is able to unconsciously filter out the aspects of the interface that distract from their everyday usage. It’s an incredible ability, and one that frees up our mental capacity to dream of such awesome things as transistors, skee ball, and bears juggling chainsaws.

We go through life largely in a state of absorbed coping. In the case of Umbach, we see that this can get us into trouble sometimes. Grabbing the hot end of a soldering iron is clearly a poor decision, and had Umbach been consciously aware of the results that would inevitably follow from his actions he would never have done it in the first place.

But we are people, and as people we adopt certain habits that are applicable in certain situations. When these situations unexpectedly cross one another, such as the strong pen-like affordance of a soldering iron triggering the pen-like habit of holding, we may find ourselves with burned fingers. As designers it’s important that we deliberately consider what the form of our products communicate to our users, even unconsciously, and design in a manner that discourages the absent-minded adoption of an incorrect interaction model.

Or maybe Hans just needs to take over the soldering from now on.

Hans and Umbach: Soldering and Building

The Hans and Umbach Electro-Mechanical Computing Company

Phew, have we got a treat for ya’ll! Last night Hans was able to tame the wild beast that is Adobe Premiere Pro, and compiled some videos of Umbach (or was it Hans?) building some stuff with Arduino.

First up, the boys soldered together an Arduino Proto Shield kit from Adafruit. You can witness their amazing efforts in super-speed time, where sixty minutes of inhaling metallic fumes has been condensed into three power-packed minutes!

After that, the boys took their new creation and built a three-channel LED color mixer, out of a few potentiometers and one of these kick-ass triple output LEDs from SparkFun.

A huge shout goes out to Ryan Rapsys of Erratik Productions for the music!

Hans and Umbach: Taking Stock

The Hans and Umbach Electro-Mechanical Computing Company

I’ve been haphazardly collecting electronics since this past summer, so one of the first things I needed to do was survey all the stuff I have at my disposal and organize the heck out of it. This spread is already outdated, as my orders from Sparkfun and Adafruit arrived last week, but it still gives a nice overview.

Hans and Umbach: Taking Stock

Here’s everything. Well, here was everything. There is far more everything now.

Hans and Umbach: Taking Stock

Buttons, switches and all that good stuff.

Hans and Umbach: Taking Stock

Tools. Tools are good.

Hans and Umbach: Taking Stock

Arduino-specific stuff, including some handmade battery and AC adapters. This last week I received a second Arduino and two Proto Shield kits, so now I’m truly ready to rock.

Introducing the Hans and Umbach Project

The Hans and Umbach Electro-Mechanical Computing Company

Last summer I began thinking about something that I referred to as “analog interactions”, those natural, in-the-world interactions we have with real, physical artifacts. My interest arose in response to a number of stimuli, one of which is the current trend towards smooth, glasslike capacitive touch screen devices. From iPhones to Droids to Nexus Ones to Mighty Mice to Joojoos to anticipated Apple tablets, there seems to a strong interest in eliminating the actual “touch” from our interactions with computational devices.

Glass capacitive touch screens allow for incredible flexibility in the display of and interaction with information. This is clearly demonstrated by the iPhone and iPod Touch, where software alone can change the keyboard configuration from letters to numbers to numeric keypads to different languages entirely.

A physical keyboard that needed to make the same adaptations would be quite a feat, and while the Optimus Maximus is an expensive step towards allowing such configurability in the display of keys, its buttons do not move, change shape or otherwise physically alter themselves in a manner similar to these touch screen keys. Chris Harrison and Scott Hudson, two PhD students at CMU, built a touch screen that uses small air chambers that allow it to feature physical (yet dynamically configurable) buttons.

From a convenience standpoint, capacitive touch screens make a lot of sense, in their ability to shrink input and output into one tiny package. Their form factor allows incredible latitude in using software to finely tune their interactions for particular applications. However, humans are creatures of a physical world that have an incredible capacity to sense, touch and interpret their surroundings. Our bodies have these well-developed skills that help us function as beings in the world, and I feel that capacitive touch screens, with their cold and static glass surfaces, insult the nuanced capabilities of the human senses.

Looking back, in an effort to look forward.

Musée Mécanique

Much of this coalesced in my mind during my summer in San Francisco, and specifically in my frequent trips to the Musee Mecanique. Thanks to its brilliant collection of turn-of-the-century penny arcade machines and automated musical instruments, I was continually impressed by the rich experiential qualities of these historic, pre-computational devices. From their lavish ornamentation to the deep stained woodgrain of their cabinets, from the way a sculpted metal handle feels in the hand to the smell of electricity in the air, the machines at the Musee Mecanique do an incredible job of engaging all the senses and offering a uniquely physical experience despite their primitive computational insides.

Off the Desktop and Into the World

It’s clear from the trajectory of computing that our points of interaction with computer systems are going to become increasingly delocalized, mobile and dispersed throughout our environment. While I am not yet ready to predict the demise of computing on a desktop (either through desktop or laptop computers alike), it is clear that our future interactions with computing are going to take place off the desktop, and out in the world with us. Indeed, I wrote about this on the Adaptive Path weblog while working there for the summer. Indeed, these interactions may supplement, rather than supplant, our usual eight-hour days in front of the glowing rectangle. This increased percentage of time that a person in the modern world would spend interacting with computing, even through any number of forms and methods, makes it all the more important that we consider the nature of these interactions, and deliberately model them in such a way that leverages our natural human abilities.


One model that can offer guidance in the design of these in-the-world computing interactions is the notion of embodiment, which as stated by Paul Dourish describes the common way in which we encounter physical reality in the everyday world. We deal with objects in the world–we see, touch and hear them–in real time and in real space. Embodiment is the property of our engagement with the world that allows us to interpret and make meaning of it, and the objects that we encounter in it. The physical world is the site and the setting for all human activity, and all theory, action and meaning arises out of our embodied engagement with the world.

From embodiment we can derive the idea of embodied interaction, which Dourish describes as the creation, manipulation and sharing of meaning through our engaged interaction with artifacts. Rather than situating meaning in the mind through typical models of cognition, embodied interaction posits that meaning arises out of our inescapable being-in-the-world. Indeed, our minds are necessarily situated in our bodies, and thus our bodies, our own embodiment in the world, plays a strong role in how we think about, interpret, understand, and make meaning about the world. Thus, theories of embodied interaction respect the human body as the source of information about the world, and take into account the user’s own embodiment as a resource when designing interactions.

Exploring Embodied Interaction and Physical Computing

And so, this semester I am pursuing an independent study into theories of embodied interaction, and practical applications of physical computing. For the sake of fun I am conducting this project under the guise of the Hans and Umbach Electro-Mechanical Computing Company, which is not actually a company, nor does it employ anyone by the name of Hans or Umbach.

In this line of inquiry I hope to untangle what it means when computing exists not just on a screen or on a desk, but is embedded in the space around us. I aim to explore the naturalness of in-the-world interactions, actions and behaviors that humans engage in every day without thinking, and how these can be leveraged to inform computer-augmented interactions that are more natural and intuitive. I am interested in exploring the boundary between the real/analog world (the physical world of time, space and objects in which we exist) and the virtual/digital world (the virtual world of digital information that effectively exists outside of physical space), and how this boundary is constructed and navigated.

Is it a false boundary, because the supposed “virtual” world can only be revealed to us by manipulating pixels or other artifacts in the “real” world? Is it a boundary that can be described in terms of the aesthetics of the experience with analog/digital artifacts, such as a note written on paper versus pixels representing words on a screen? Is it determined by the means of production, such as a laser-printed letter versus a typewriter-written letter on handmade paper? Is a handwritten letter more “analog” than an identical-looking letter printed off a high-quality printer? These are all questions I hope to address.

Interfacing Between the Digital and Analog

Paulo's Little Gadget by Han

I aim to explore these questions by learning physical computing, and the Arduino platform in particular, as a mechanism for bridging the gap between digital information and analog artifacts. Electronics is something that is quite unfamiliar to me, and so I hope that this can be an opportunity to reflect on my own experience of learning something new. Given my experience as a web developer and my knowledge of programming, I find electronics to be a particularly interesting interface, because it seems to be a physical manifestation of the programmatic logic that I have only engaged with in a virtual manner. I have coded content management systems for websites, but I have not coded something that takes up physical space and directly influences artifacts in the physical world.

Within the coding metaphor of electronics, too, there are two separate-but-related manifestations. The first is the raw “coding” of circuits, with resistors and transistors and the like, to achieve a certain result. The second is the coding in Processing, a computer language, that I write in a text editor and upload to the Arduino board to make it work its magic. Indeed, the Arduino platform is an incredibly useful tool for physical computing that I hope to learn more about in the coming semester, but it does put a layer of mysticism between one and one’s understanding of electronics. Thus, in concert with my experiments with Arduino I will be working through the incredible Make: Electronics: Learning by Discovery book, which literally takes you from zero to hero in regards to electronics. And really, I know a bit already, but I am quite a zero at this point.

In Summary

Over the next few months I aim to study notions of embodiment, and embodied interaction in particular, in the context of learning and working with physical computing. As computing continues its delocalization and migration into our environment, it is important that existing interaction paradigms be challenged based on their appropriateness for new and different interactive contexts. The future of computing need not resemble the input and output devices that we currently associate with computers, despite the recognizable evolution of the capacitive touch screen paradigm. By deliberately designing for the embodied nature of human experience, we can create new interactive models that result in naturally rich, compelling and intuitive systems.

Welcome to the Hans and Umbach Electro-Mechanical Computing Company. It’s clearly going to be a busy, ambitious, somewhat dizzying semester.

Version Zwei


Apologies to any Germans in the audience for brutalizing your beautiful native tongue.

Going Indie

It’s barely December, but I’m so sick and tired of this semester that I’m already working on next year. Kate was nice enough to get me Phaeton as an early Christmas present, and so I’ve been working on the art direction for my independent study next year:

The Hans and Umbach Electromechanical Computing Company

This is gonna be a fun one.