Below are videos demonstrating the multiple versions of code I used in the cubes while testing.

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)

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