ideation :

The first (possibly, we're no longer sure) idea involved a cube of photoresistors. A sort of flashlight for a horror game. That spawned ideas about a punishing, non-visual horror game. That led to a 4x pressure sensor controller for a horror game (eventually abandoned). And that (eventually) turned into the initial thought behind {cuff}: why not let a horror game use additional input (read: sensors) to enforce certain playing conditions?

We really liked the idea of using what happens when a player plays a game (increased heart rate, perspiration, fidgeting) to influence how the game itself behaves. Our current prototype uses (1) a pulse sensor to approximate the player's emotional state and (2) an accelerometer to enforce motion constraints (stillness or the lack thereof).

video :

{cuff} provides two basic features: (1) pulse detection (to spawn an asteroid on every second beat), and (2) motion detection (to violently throw asteroids across the screen at the slightest twitch). So as heart rate and fidgeting increase, the game's difficulty -- or fun factor, depending on how you look at it -- increases.

components :

  • processor: arduino (leonardo)
  • sensors
    • pulse sensor
    • lilypad accelerometer
  • wristband: heavy, canvas-y cloth secured with heavy-duty thread
  • connective tissue
    • conductive thread
    • 3 long pieces of solid-core wire (crimped)
    • 4 long pieces of stranded wire (wrapped)
    • electrical tape

challenges :

  1. Pulse sensors. We wanted something subtler, less invasive, so we went with a wristband (a la fitbit). We didn't, unfortunately, have a pulse sensor that fit on the wrist. They exist; we just couldn't find one to prototype with.
  2. Analog input. We had to figure out how to use the data: did we want BPM? just peaks? something more complex? Ultimately, we set dynamically-adjusted thresholds to approximate heartbeats, and spawned asteroids on every other beat. Mapping the accelerometer data was more direct: the deltas fed asteroid velocities.
  3. Wires. They were annoying to crimp, annoying to connect, and annoying to keep connected. They were also mildly annoying to sew (though this was mostly because we wanted a reasonable-looking wristband -- meaning <= 1.25" wide).

thoughts :

MPA01 was a fun project, though we needed the additional time to get any real results. Having to use an arduino was, perhaps, also too limiting. Components were scarce at times, and several skills we needed had to be learned on the fly (e.g. wire crimping), but it was, overall, rewarding.

links :