Hardware Hacking Projects for Geeks

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Chapter 8, How to Hack a Building-Size Display

6. Mount the system on your house

After you have tested the LED array on the ground and installed the option-

al light diffuser, it is time to mount the system on your target building.

It is probably safest to drop hoisting ropes from the windows where the

array will be secured and slowly pull it up just under the window height.

Secure the ropes that hold everything in place and carefully connect the

wires.

Your hardware is now complete! Skip ahead to the Software Setup

Instructions.

Large-Scale Hardware Assembly Instructions

The CCC installed the Blinkenlights system on the top 8 floors of a 12-

story building. Behind each of the 18 front-facing windows on each floor,

there was a single lamp on a handmade tripod. Each lamp was connected

to a power source via a relay; if the relay switched on, the windowpane

became lit. The building in Berlin had all of the windows painted white to

act as a diffuser, which may not be practical for you. Instead, you can place

a white cloth or paper sheet in front of each window to keep the light from

looking like a point source. All of the lamps should be similar to ensure

uniform illumination of all of the “pixels.”

In the Berlin project, each relay was connected to the control floor via a

cable. All the cables came together in a huge bundle of cables connected to

the Blinkenlights Chaos Control Center. An amplifier provided the cables

with the necessary power to switch the relay; the control computer was

capable of switching each relay independently. More than 5,000 meters of

cable was required to wire the building.

In the following steps, you will find an appropriate building for your dis-

play, build the relay drivers and boxes, and wire the building.

1. Choose a building for installation

The Blinkenlights system consisted of a matrix 18 pixels wide by 8 pixels

tall. You should choose a building in which the number of windows facing

outward is close to this number, but it does not have to match exactly since

you can create smaller animations and images with the software tools.

You could even build the display on an 18-story building with 8 windows

across; in this case, you would need to create the images and animations

sideways.

The building should have easy access to each of the window “pixels.” You

will be running a cable from each lamp to a central controlling PC, so make

sure that you can access stairwells between floors. Each window should

have an electrical outlet near it as well.

Large-Scale Hardware Assembly

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