Power puncher (1997)

Doors in the Caltech houses use five-button combo locks.

Punch buttons. Turn latch.

One of my first projects was a device to crack the locks by trying all possible combos.

Stepper motor turns latch. Sensor detects success. Solenoids punch buttons.

It requires a 12v RC-car battery and a lot of patience.

Air guitar (1998)

My senior project at caltech was an electronic air guitar.

Distance between hands determines "fret". Bend a finger to pluck one of four "strings". Curl a finger to slide between notes.

This box goes in your left hand. This glove goes on your right hand. LCD shows what notes you're on.

The guitar sound is synthesized with sample playback. Distance is measured ultrasonically.

Coke machine (1998-1999)

Start with an ordinary coke machine.

Add an LED display and clock display in the window.

Modify or rebuild the machine's guts, for complete control over button pushes, coin deposits, soda dispensing, and coin returns.

Write a firmware operating system and drivers, so the machine acts as a computer peripheral.

Design a software API, so everyone can write programs for the coke machine.

Applications: buy cokes on account by punching in a "password", play games, check email, buy cokes over the web...

The coke machine was first hacked by Walter Brisken with Blake Jones. Contributors to my revamp included Steve Ginzburg, Jeremy Boulton, Peter Maresh, and Andy Griffin.

LED matrix (1997)

I had a bunch of LEDs lying around. So, I built a 30 x 7 LED display...

... and designed a full-custom VLSI graphics processor to drive it. (Supports 4-bit color depth, 16 shades of red.)

But the chip didn't get fabbed, so I hooked the display to my parallel port. (Software-driven 2-bit color depth.)

Later, I gutted the circuitry again to use it as the Coke Machine display. (Firmware-driven 3-bit color depth.)

It was even embedded into a wall of my room as part of my ditch day stack.

This little display has really gotten around.

Networked air conditioner (2000)

There's nothing worse than walking into a hot, stuffy apartment during a humid Philadelpha summer.

My then-girlfriend wished she could turn on her air conditioner from work.

Call home, and let the answering machine pick up. Punch in a code. A/C hears code and turns on!

When you are with a EE, be careful what you wish for.

Microphone listens for touch tones. IR LED turns on A/C from across the room, by mimicking the remote control.

I gave it to her for her birthday. The digits of her birthday were the secret code.

Mailbox flag (2000)

I used to live at the top of a hill. The mailbox was at the bottom. Getting the mail was quite a hike.

My roommates and I often wanted to know whether the mail had come, and if so, whether someone else had already grabbed it.

Light sensor inside box detects mail. Motor flips up a flag When mail is inside.

Motor flips the flag back down when mail is removed.

One day, the landlords replaced the mailbox. i had to retrieve this project from the dumpster.