BMX handlebars as a wireless controller

I just got back from San Francisco. I did something I often do when I visit there (in addition to eating a gigantic crustacean). I always try to rent a mountain bike and do a half-day ride along the water towards the Golden Gate. My gig in SF was an exercise in mimicking real life - I provided a videogame experience of a cyclist on the streets of San Fran from Lombard Street to Fisherman’s Wharf! 2nd life meets 1st life! The bike game was to be a fun experience for kids at a Hemophilia convention which felt more like a street fair full of kid friendly activities. I’m honored that our bike game was one of the activities. The goal was to illustrate, in a fun way, 11 reasons why a particular medication is useful. Experience is a word I spend a lot of energy contemplating. The client wanted a custom videogame from the outset, so I, along with Sam Ewen at Interference Inc happily obsessed over how we might make the game a memorable and interesting virtual experience.

First method for creating the “experience”: throw out the traditional videogame controller. I’ve been playing with Arduino’s for the past few months. Awesome little guys that they are, I devised an Arduino (teamed with an Xbee and either an Accelerometer or digital compass) as the brain of a real-life set of bicycle handlebars used as a wireless controller. $25 later, my new buddy Jace Van Auken produced a set of black BMX handlebars with mushroom grips :) These were perfect because they had a space for fitting the technology and the 9volt battery to drive it all. Funny side note, I was at a tradeshow in Philadelphia and sent him a photo of the kind of handlebars I wanted using coffee stirrers on the carpet of the Philly convention floor, see the link. Looked great. Thanks Jace.

Second method to achieve the “experience” : recreate the streets of San Francisco. Why was this a cool idea? Almost all of the attendees of the Hemophilia event are families visiting SF from out of town, many have visited Lombard street or the Wharf just the day before. I was pleased to hear, several times, “look honey, we were on that street yesterday!” I consider that a big win, we tapped a family activity fresh on players’ minds.

Hardware and software:
I’m a fan of open source, I like the organic nature of communities that form around a project that is basically owned and grown by it’s voluntary contributors. It also means there is a huge support structure if I find myself in need of assistance. My way of giving back to a community is to include the open source tools in my installations in order to bring awareness to the toolset being used professionally and by the public. On this installation we used both open source software AND hardware. Read on.

Blender3D, an often underestimated 3D modeling and animation program, was used for the main game via its realtime game engine. The true strength of Blender3D, for me, is how accessible everything is via Python in ittybitty little scripts. I found myself in a situation where the Blender artist we hired couldn’t complete the job. I put an ad for help out on some public forums and had a handful of responses within hours! 7 responses almost immediately and twice that over the next day, A testament to the Blender community. I’d like to officially thank Blendenzo, moderator at www.BlenderArtists.org for his invaluable help. He is a pro, an efficient worker, and his work ethic is exactly what you'd want when the clock is ticking. If you have need of an ace Blender artist, I urge you to contact him. For time’s sake, we stripped a bunch of elements out of the game engine so I could recreate them in Flash (a tool I’m much more proficient with). Blender+Flash you ask? That’s right, we used some nifty Python to enable the two to communicate and seamlessly switch between the running game engine and Flash Player. We swapped data such as scores, different game states, and the choice of in-game cyclists totally on the fly. We divided and conquered. The whole process ended up quite smooth.

In terms of hardware, the Arduino is an exciting bit of kit. As an open source project, you can follow plans to build your own on any shape breadboard you please. We used the off-the-shelf Arduino Duemilanove. One sits at the computer with an Xbee wireless receiver. Another sits in the handlebars with the Xbee transmitter, Accelerometer, and 2 contact closure buttons. The tricky part of this set up was that I tried to steer clear of sending serial output directly to Blender (blender can certainly handle this as Python can access a serial data stream over usb via PySerial libraries). I wanted to avoid this to make life easier on my first Blender artist, he designed with keyboard keys as a controller, so we had the Arduino emulate a real keyboard and send keystrokes based on the accelerometer’s movement. A neat trick. An added benefit is that I can remap those keys for use in just about anything that will receive a keystroke now :) Spyhunter anyone?




From a purely HCI standpoint, the handlebars did a good job of providing an unexpected experience (no Wii controller here), while simultaneously engaging observant passersby (wondering what the deal is with the untethered handlebars). Using the familiar real-life object, and making a connection between the virtual experience to a real experience which resides in another realm for the user, in this case a family related experience (the prior touring of the SF sites found in-game), creates an emotional association with the game as its being played. Such associations are great as they’re tough to unlink, nostalgia for one means nostalgia for both. That’s great for both the player and the brand.