Friday, September 27, 2013

Motion Tracking Skull for Halloween

Interactive Halloween props are always fun. So in this project I designed a simple motion tracking system that will make your Halloween props turn to look at people and follow their movements as they walk by.

To do this, I mounted a servo to the bottom of a foam skull. Then I set up an array of light sensors  in front of it. When a person walks in front of it, the light sensors will detect the person’s shadow. An Arduino then calculates where they are standing and turns a servo to face them. When they move, the system adjust and turns the skull to face their new position. You can set this up on a shelf or fence where people will be walking by. It stays still until someone is right next to it. You can surprise a lot of people simply because they aren’t expecting it to move.


Tuesday, September 17, 2013

Haunted TV Prank

Halloween is just around the corner. So it’s time to start building projects to scare and prank your friends. I decided to start off this year by making a haunted TV. In this project I show you how to use a cheap pair of walkie talkies to make strange and eerie sounds come from your TV. One walkie talkie is hidden inside the TV. When you speak into the other walkie talkie, your voice will appear to come from the TV.

You could pretend that it is a ghost. You could pretend that the TV is intercepting signals from aliens. Or you could make it appear that they TV is bugged and you are being watched by big brother with a SWAT team closing in. Use your imagination and have fun.

Tuesday, September 10, 2013

Remote Tripwire Alarm

A tripwire is one of the most basic ways to set up a simple security system. You run a line across a pathway. Then when someone walks through the line, it activates an alarm. This kind of system is easy to set up and is fairly effective. But there is always room for improvement.

The most inconvenient thing about a classic tripwire alarm is that it requires you to run a physical line from the tripwire to the alarm. This makes it difficult to set up a system where the alarm is far away or inside a building. To get around this problem, I designed a simple remote alarm system that uses a small radio transmitter to activate the alarm wirelessly. So in this project, I am going to show you how to make a simple remote tripwire alarm.


Thursday, September 5, 2013

How to Transplant an RFID Chip

RFID (radio-frequency identification) systems are all around us. They help us get through toll booths faster. They help stores keep track of inventory. They are even in a lot of toys.

But there is no reason why the RFID chips need to stay in their original housing. In this project, I am going to show you how to transplant a RFID chip into a different housing to make it more convenient or at least more fun use. You can make an RFID reactive wallet, multi-tool, or cell phone case. My favorite was a RFID magic wand. That way you could open your office door with a magic wand. The only limit is your imagination.


Giant Cardboard Dinosaur Puzzle

A few weeks ago I purchased some small 3D wood puzzles to build with my son. Among them was a pteranodon. I thought that it was a really fun model, but it was too small. So I scanned the pieces and blew them up about 500%. Then I cut the pieces out of cardboard to be lighter. The result was a giant pteranodon puzzle.