Intruder Alarm McDonald’s Toy Hacking

[malikaii] needed to set up some kind of tripwire style alarm system for his office. His bosses kept sneaking in to find him slacking. So, like any loyal hacker, instead of just working harder he built an alarm system. After a failed attempt to recreate an IR alarm circuit he found on the web and built from old appliance parts, he found the Hack a Day article about harvesting McDonald’s toys. The end result was a fully functional IR detecting alarm for the office doorway. This is pretty simple really, the best kind of hack.

Solenoid Motor From A VCR Head

[youtube=http://www.youtube.com/watch?v=3nHX-66PGN0]

Here’s a solenoid motor you can build from a VCR head and some common components. It uses an LED and a light sensor, paired with an LM311 comparator to manage the switching of the motor. As the head turns, the LED shines on the sensor through a hole and triggers a TIP120 transistor to turn on the motor during the power stroke. Once the beam of light is broken, the transistor turns off the motor and the momentum carries it through its revolution until the next power stroke is activated.

We often say that “why” is the wrong question. [Bd5940] must feel the same way because he ends the video by saying: “it has no use, but definitely a conversation piece”. Yep, we’ve seen that before.

[Thanks James]

USB Host For Propeller Micros

[Micah Dowty] has implemented full speed USB host control on a Propeller microcontroller. He’s motivated by the thought of using USB based WiFi and Bluetooth dongles in his projects as ready-made solutions.We’ve seen USB host control with the Arduino and it really opens up the flood gates for advancing your projects through storage, wireless connectivity, and user interface.

So far his work is fairly preliminary but the results seen from other participants in the Parallax forums are very positive. Check out his code from the subversion repository and lend a hand with the development.

[Thanks Stefan via Adafruit]

Touch Screen For Graphing Calculator

[youtube=http://www.youtube.com/watch?v=pyWIJFLbJZ0]

[Owen] got down and dirty by adding a touchscreen to his TI-84 graphing calculator. The dirty part is the z80 assembly code he wrote to use the linkport as a UART (assembly always makes us feel queasy). Once that was working he implemented some commands using an Arduino and then hooked up an Nintendo DS touch screen. Now he’s got this proof of concept video where he draws on the screen, that input is interpreted by the Arduino, commands are sent through the UART, and the calculator program draws on the screen. Adding a touch screen to something is a lot more impressive when you have to go to these lengths to get it working. Nice job!

Illuminated Moveable Type

[vimeo=http://vimeo.com/10437744]

[Rob Stewart] put in a lot of time and built this lighted display at great expense. It displays four letter words using a word association algorithm to pick the next term to show. What interests us is the motorized display. It is made up of fluorescent tubes but they’re not fixed in place. Each can be rotated, as well as moved along a linear path to form any letter in the alphabet. Check out [Rob’s] build logs for the details on how he pulled it all together.

[Thanks Hugo via Engadget and Switched]

Flood Triggered Camera

When the Department of Natural Resources of Australia decided that they needed to capture data about the natural flooding of a cave, they turned to a hacker to get results. The goal was to photograph the area during these floods with an automated system. In the end, they used a gutted Lumix digital camera mounted in a trash can, covered in aluminium foil. Though it sounds a bit silly, the final product turned out quite nice. You can see the build log, schematics, and results on the project page.

[via hackedgadgets]

Update: 50MHz To 100Mhz Scope Conversion

Changing this 50MHz Rigol oscilloscope into its larger, more expensive brother just became quite a bit easier. When we originally looked at this hack it required pulling some capacitors off of the board. Now all it takes is three commands over a serial terminal connection.

Take a look at the walk through video after the break. You’ll see that there’s one chip that needs to be setup differently to change the functionality. Removing capacitors was actually changing the commands sent to initialize that chip at power-up. Now you can just change the model number and one letter of the serial number via a terminal and the firmware will recognize this as the more expensive DS1102E.

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