Knowing how to build something, physically or virtually, will get your designs further.

Sometimes when I’m learning a new programming language, arduino, or electronics, I wonder if my time is best spent learning something that isn’t specifically about interaction design. I know I will never be a pro at object-oriented programming, fully understand what a capacitor does, or be able to hack an arduino to control my twitter feed.

But… it does feel great to build something and see it working in front of you! …it does feel great to take a crazy idea that is impossible to explain to someone and build it for them to understand firsthand!

Learning bits and pieces of PHP, Processing, Flash, electronics, and Arduino during my time in the Masters program has been invaluable knowledge. It isn’t directly about interaction design, but they allow me to directly demonstrate and explain my interaction design.

• button double-press (hold red light on)
• button press hold + touch tap (switches rainbow color)
• button press hold + touch hold (cross fades between rainbow colors)

My initial electronics design made use of a very small code library that would allow me to sense the touch of the button. This method did not require any additional hardware and used only a small amount of code to detect the touch. (See photo above) It is a great piece of code and only requires connecting a single wire to a single digital pin on the Arduino.

However, this method did not work for the level of control that I need for my cube. My basic debugging showed that the touch is being consistently detected, but the detection cycles quickly between “touch” and “no touch”. For my cube, I need to be able to detect when a finger is touching the button for more than 1.5 seconds, an action I’m calling a “hold”. This “no hardware touch detection” would cycle between “touch” and “no touch” so quickly when my finger was “holding” on the button, that I wasn’t able to accurately interpret the “hold” action.

I instead moved towards a “hardware required touch detection”… (see video)

The button touch is now being detected by the Quantum QT110 QTouch Sensor IC (chip). Only a simple setup is required, connecting the chip to power, ground, a capacitor to filter out noise, a wire that will be touched, and one digital pin on the Arduino to receive the HIGH/LOW output signal. The good thing about using the chip, is that it does the touch processing for me and outputs a simple HIGH/LOW signal to the Arduino, and also allows me to detect the “hold” action! Integrating this chip to the electronics was almost too easy. The only custom wiring I did was to lengthen the “auto timeout” from 10 seconds to 60 seconds. I changed one wire from power to ground for one pin on the chip to achieve this.

Functionality so far:

• button press (red light on)
• tap button touch (blue light on, repeats number of taps)
• hold button touch (blue light, cycles brightness up and down)

I never thought I would hear myself say that! Thanks to my classmate, Katrina Anderson, for the perfect idea of sewing conductive thread on top of a monome.org style rubber button.

Many updates to catch up on…

I have decided on a direction for the final prototype: a small cube with a single touch-sensitive button, that abstracts the idea of a SUI, with playful and contemplative interactions. The first step, of course, is to create this cube.

My plan is to laser cut plexi for the cube, use a monome.org style rubber button, make the top of the button touch-sensitive, include some AA batteries, throw in an Arduino Pro board and maybe an RGB LED… and POW!… a “SUI Cube!”

3rd Test of making the rubber button touch sensitive… (the 1st and 2nd attempts were with variations of using a QT110 touch sensing chip or a bare wire, both of which failed)

I know of capacitive touch chips that are available, for example, at Sparkfun. But why do I need an additional chip for sensing touch, when apparently I can do the same sensing with a piece of wire connected to the arduino? See video…

Hardware setup and Arduino code available in Arduino Playground: Native Capacitive Sensors without additional Hardware

Final Prototype

Schematic Diagrams

Entire Electronics Schematic

Arduino Connections (zoom view)

Parent Multiplexers (zoom view)

Children Multiplexers/IR Phototransistors (zoom view)

Switches/Laser Transistors (zoom view)

Parts List

• Arduino Duemilinova (1)
  • #12200020 from Electrokit.se
• 4051 Multiplexer (16)
  • #73-473-70 from ELFA
• IR Phototransistor (110)
  • #75-203-15 from ELFA
• IR Laser (2)
  • 35mW 980 nm Infrared
  • 120 degree line generator
  • #A-H980-35-3 from Aixiz
• Switch (2)
  • Push Button PCB 0.8 mm black
  • #41001412 from Electrokit.se
• Transistor (2)
  • BC337-25 TO-92 NPN 45V 500mA
  • #40320009 from Electrokit.se

Code

• Arduino: TRKBRD_build_8_8.zip [6 KB]
• Serproxy (to send data from Arduino to Flash)
• Flash movie to receive TRKBRD data: TRKBRD_flash_build_5.zip [1.8 MB]
  • Be sure to adjust the Flash security settings to allow this movie to play locally on your computer.

Video Documentation

The two prototypes that I built were the TRKBRD and the MemoryWatch. In reference to my diagram below, I attempted to position each prototype as the red X, which is exactly why both projects failed to meet their deadlines and needed extensions throughout the summer. What follows is an explanation of the sage advice I received from the fellows at Unsworn Industries, during their critique of our FashionTechnology final presentation.

When you have your idea, and want to begin prototyping your idea, no matter if your idea is physical or virtual, first think of how that prototype will fit into the matrix below. What is the most important element, or elements, for your idea or design? Most people, when they begin prototyping, fall into the pitfall of immediately aiming for the red X below, where the resolution and the fidelity are both perfect! This is not the best place to start prototyping. Consider restricting the resolution, so you can concentrate on the fidelity. Or, consider restricting the fidelity so you can concentrate on the resolution. Think of your prototypes as small steps towards achieving that final red X position of perfect resolution and fidelity. And remember that it takes many steps before achieving that final position!

from Make Magazine:

The video mentions that the necessary supplies are available from Jameco, but they can only ship the supplies by ground, which presents us in Europe to receive it. I think ELFA in the EU has the supplies but I am still trying to find the necessary pieces.

Electrokit in Malmö has the necessary supplies:

• Developer #41000469
• Etching #41002328 or #41002488
• UV lamp from some other store
• Light-sensitive boards such as #41004123

Last night, I laid in bed unable to sleep. It was already late, but decided to get up since I wasn’t accomplishing anything by just laying there. The conference session was on my mind, so I got up and started sketching out ideas for my presentation. It is an understatement to say that I’m nervous about the session. Though, I’ve had some practice with presenting the TRKBRD.

After presenting at Ergonomidesign in Stockholm late last year, I got some great feedback relating to my conference session: the session should tell the story. I’m talking about how “physical prototyping” helped my project and gave me a result that would not have been possible otherwise. Other people will also be talking about the technical hardware (Massimo Banzi and the Tinker.it Toolkit). Besides, there’s no way you can talk about the hardware in under 40 minutes. I will be telling the story of me and my TRKBRD, happily running through the fields in the late afternoon sun!

The sketch attempts to outline the path I took for the project:

1. got the idea
2. explored how arduino could help me, which sensors?
3. research, research, research, and people
4. many trials and errors…
5. trial success!
6. documentation
7. exposure
8. demo’s and testing
9. future?

There are a lot of little thoughts throughout the sketch. My first pass outlined the major sections of the drawing. I then went back with my pencil to write in small notes for each section. It was a nice way of slowing adding fidelity to the drawing. Quickly do the first pass, to just get it down on paper. Then go back and add more details in multiple iterations of going around the sections.

This sketch has helped me a lot so far in just trying to organize my thoughts. Also, it allowed me to finally get to sleep last night too!