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 Instead of simply replacing the outdated bulb, we decided to build a small dark detecting circuit with 2 yellow LEDs based on this Evil Mad Scientist Laboratories design.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.

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Aspire One 3G Hack

October 29, 2008 by Eliot 12 Comments

[tnkgrl] is back with part three of her Acer Aspire One hacking. This time she’s adding in 3G. You may look at the picture the above and think, “Cake. She just plugged the card in”. No, the Acer doesn’t ship with the mini-PCIe slot or the SIM card holder. First you have to solder a right angle mini-PCIe connector to the board pads and bridge two others to provide power. The SIM holder was another problem. She wasn’t able to find a pin compatible one. The one she installed is mounted to a riser so she could change the wiring order (let her know if you can find the correct part). This mod definitely requires some good soldering skills and she warns that even she managed to destroy a SIM in the process.

The Dell Mini 9 is another netbook that doesn’t have the appropriate connectors soldered on board, but JKK has a work-around. You need a 3G modem that has the SIM card on board. You plug it into the WiFi slot after taping over a few pins and then use a USB WiFi card instead.

Cellular Automata And LED Matrix Fun

October 28, 2008 by Caleb Kraft 7 Comments

Blinkomat, an LED matrix, turned out quite well. 240 LEDs controlled by an Atmega 16 is what we call a decent bookshelf decoration. The dimensions of 12×20 were chosen due to the fact that the microcontroller has 32 I/O lines. The LEDs are switched on and off using multiplexing. The brightness, controlled by pulse width modulation can be varied by 16 levels. The overall effect is quite smooth an fun to look at. He has programmed it to do other things than just cellular automata. Our personal favorite is a simple sine wave. Watch it after the break.

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Making The PSP Not So Portable

October 27, 2008 by Caleb Kraft 15 Comments

[alien x] has posted this peculiar hack for a PSP. He has gutted and splayed the PSP spreading its insides neatly and mounting them on a plexiglass back. Everything is easily accessible and ready to tinker with. It may not fit in your pocket, but adding mods and experimenting with ideas should be much easier like this. It looks pretty cool too, we want one for our office wall. That could be possible too, he’s selling it.

[thanks doodle]

Coin Slot Detector

October 24, 2008 by Eliot 33 Comments

Wow, how quickly the wearable electronics world has slid into the gutter. They’re now resigned to watching our nations finest natural resource, the butt crack. This project by [semiotech] uses a LilyPad Arduino to monitor the exposure of the wearer’s coin slot. It detects the presence of light with a photoresistor and alerts the user with the vibrations of a pager motor. This breakthrough in coin slot technology will prevent dryness and certainly reduce our exposure to domestic terrorism. We see plenty of room for future development; the Arduino is already capable of logging exactly how often your coin slot is exposed. Even if you feel this is more protection than your coin slot needs, we recommend Neutrogena’s Coin Slot Cream for general upkeep.

Quick Cheap Cassette Adapter

October 24, 2008 by Caleb Kraft 18 Comments

[Dane] sent us this super quick tape adapter project. Yes, we know we can go buy one of these for pretty cheap and it will probably sound much better, but really, wouldn’t it be cool to make one? Using a headphone adapter, a couple resisters, some wire, and an old cassette tape, [Dane] shows us how easy it is to build one of our own. You are basically pushing the signal from the headphones through a coil that is up against the tape read head. This is a perfect project to teach beginners about magnetic fields.

[Dane] has sent in some stuff before. You may recall his PWM adio generation with an AVR post several months ago.

Uv Oven From An IKEA Cabinet

October 23, 2008 by Caleb Kraft 7 Comments

This may not be an amazingly complicated project, but it is a very elegant and fairly cheap way of building a UV oven for exposing PCBs. [aris] started with an IKEA FIRA cabinet. He basically left the framework as an empty shell and made a make shift top hinged door to enclose it. Mounted in the top is an array of 35 UV LEDs powered by an HP printer transformer. He did not have a timer circuit, instead he just watched the clock and unplugged it at the right time. You can see from his pictures that his results were quite good.

If you don’t want that piece of furniture taking up room, and don’t mind using a little more elbow grease, you could follow our directions on how to make your own single sided PCB. If money isn’t an issue either, you can always just get your PCBs laser etched.