Flickering LED Circuit

October 30, 2008 by Nick Caiello 16 Comments

Here’s a simple project for your Halloween celebration. The other day while looking through our box of Halloween decorations, we noticed that the incandescent lamp in one of the jack-o’-lanterns was burnt out. Instead of simply replacing the outdated bulb, we decided to build a small dark detecting circuit with 2 yellow LEDs based on this Evil Mad Scientist Laboratories design. After successfully building the circuit, we took the project one step further by incorporating an Atmel ATtiny13 microcontroller. The code switches the LEDs on and off randomly for a flickering effect and is based on this instructable. Below is the schematic we created in EAGLE and a parts list.

Continue reading “Flickering LED Circuit” →

Adafruit Arduino Sale

October 26, 2008 by Eliot 19 Comments

With the release of the Arduino Duemilanove, Adafruit is trying to shift out some old stock Arduino Diecimila by offering 10% off. [amk] noted that the new Duemilanove is not so much an upgrade as an Arduino with a new hat. The only changes were autoselecting power and a cutable reset line. The best part about the Adafruit sale is they’re offering Atmega328s preloaded with the Arduino bootloader as a $5 upgrade. The Atmega328 gives you twice the flash memory, twice the RAM, and twice the EEPROM than the original Atmega168.

Tiny Optical Theremins

October 25, 2008 by Eliot 16 Comments

Matrixsynth pointed out a couple incredibly small optical theremins that look like they’d make for a great afternoon project. [AlexArt] first built the simple circuit on a piece of protoboard (Google translated). Knowing he could go smaller, he then built it freeform with a buzzer instead of a full size speaker. The design is based around the common 555 chip and photoresistor. Here’s a simple circuit you can use to lay out your own. The optical theremin should not be confused with the traditional RF theremin since the name comes from the similar sound, not similar construction.

LED Life And Charlieplexing

October 24, 2008 by Eliot 8 Comments

Yesterday, we featured [Andrew]’s orientation aware camera. We want to highlight another one of his projects: LED Life. It’s a 6×5 LED matrix playing Conway’s Game of Life. He used the low power MSP430 like our e-paper clock. The best part of the writeup is his explanation of how Charlieplexing works. Microcontroller GPIO pins generally have three possible states: output high, output low, and input. This combined with the directional nature LEDs and some creative wiring means you can run a large matrix of individually addressable LEDs with just a few IO pins. Instead of just flipping the IO pins on and off you change their assigned state. Have a look at [Andrew]’s site for some great illustrations of how the system works. A video of his LED Life board is embedded below. Continue reading “LED Life And Charlieplexing” →

Sticky Tape Emits X-rays

October 22, 2008 by Eliot 37 Comments

Wired posted a gallery covering an interesting phenomenon. When you unroll regular sticky tape it emits visible light, but what was recently discovered is that under vacuum it actually emits x-rays as well. They’re still trying to nail down the cause. Have a look at the gallery of UCLA’s research lab to see what kind of equipment you need to unroll tape in a vacuum.

INTERNATIONAL CAPS LOCK DAY

October 22, 2008 by Eliot 46 Comments

As you can plainly see, we’re embracing International Caps Lock Day with full gusto. Go ahead, try it out in the comments. Caps lock is the cruise control for cool. Surprisingly, there are quite a few full time haters of the key running campaigns: CAPSoff and anticAPSLOCK actually united to form CAPSoff.org to further development of a caps lock free keyboard.

Once you’re tired of yelling at people online (like that’ll happen), you might attempt to do something useful with the key. In OSX, you can remap the caps lock key in System Preferences > Keyboard & Mouse > Modifier Keys. You can make it an extra Command, Control, Option, or select No Action. If you want to map it to another key entirely, try a program like fKeys. You could map it to Esc to make Vim—THE BEST TEXT EDITOR EVER—easy to use. In Windows, try this handy guide from TechRepublic for remapping your keys.

If ease of use is not your goal, you could always make a random caps locker hardware dongle.

[photo: catcubed]

Björk Teaches You About Electronics

October 20, 2008 by Eliot 89 Comments

[youtube=http://www.youtube.com/watch?v=75WFTHpOw8Y]

As we often suspected, [Björk] is quite the technical mastermind. In the video above, she teaches you about the ins and outs of her television. We think she’s making a strong bid as the next person to join Prototype This! Her hacking philosophy is the same as ours: “You shouldn’t let poets lie to you.”