[Ladyada] has released this tutorial on using pressure sensors. They cover everything from the basics of their construction through how to connect and read data from them. The elegant sensor pictured above is available through the adafruit store, but you could always build your own.
[thanks pt]
[youtube=http://www.youtube.com/watch?v=PGRBjCrnjhs]
Here’s another hacked Nerf Vulcan rifle. This time it is an automated sentry gun. You must present it your badge, if no badge is found, you are assaulted with a fiery storm of small nerf darts. All encounters are logged and a photos are kept. This was a final project at Cornell, and for once it wasn’t ECE. This was for CS1114. They did a pretty good job with the tracking, now they need to add some more interesting voice options to it.
[youtube=http://www.youtube.com/watch?v=Mhu3zojL5Y4]
[Jeri] put together an absolutely massive Etch A Sketch for The FatMan and Circuit Girl show. She had removed the DLP chip from an HD rear projection TV and decided to repurpose the 52inch screen. The movement mechanism uses pulleys from screen doors with nylon lines. The two sets of lines are fed in a criss cross pattern so that the parallel lines move in the same direction. The lines move tent poles in the x and y which controls the movements of the golf tee stylus. It’s driven by two high torque motors from $9 Harbor Freight 18V drills. They tried several different powders, but ended up using aluminum powder from an original Etch A Sketch because it sticks to everything. It will eventually be hooked up for IRC bot control once they get a large enough h-bridge.
[via adafruit]
[youtube=http://www.youtube.com/watch?v=HI3KNy9GKB8]
[dunk] sent his home made Radio Control system. It is constructed from a Playstation 2 controller, an Atmega 2561, microcontroller, some RF modules and various servos and motors. It seems to work pretty well. You can get all the schematics and source code on his site. Several people have submitted a similar project which involves an iPhone and a helicopter, but that one is a bit dubious, mainly due to it’s lack of detail.
[Daniel] had to have runaway in his mind when he built this coil gun. It’s hand held, holds 14 42 gram rounds and can propel them at speeds of 110km/h. Of course when it is battery powered, you have a 90 second warm up time between shots. It can also be used while plugged into a wall socket, which reduces the charge time to roughly 3 seconds. Great job [Daniel].
[via engadget]
We really wish we had a little more information on the construction of this, but [Jeff] made this APRS tracker several years ago. APRS, or Automatic Packet Reporting System is a system where shortwave radios put out small packets of data that are uploaded to a database available via the web. This specific one is relaying GPS data so his family can see where they are located. With current phones, you might think this is antiquated, but he notes that he took this through New Mexico and was able to transmit his position even when there was zero cell phone coverage.
[youtube=http://www.youtube.com/watch?v=H1TelXmRQs0]
This project is particularly amusing. It doesn’t have a whole lot of practical use, but it makes up for it in style. They have an SD card with Wikipedia from 2003 downloaded to it. This is accessed with a Parallax propeller microcontroller based system and displayed on a small retro looking screen. We like it. We don’t think we would ever actually use it, but we would definitely keep it around.
