Building A Glue Stick Flashlight

June 9, 2010 by Mike Szczys 29 Comments

Building an LED flashlight is simple, right? Take a battery, connect it to an LED by way of a resistor. Alright wise guy, now make one that steps up the voltage for multiple LEDs and don’t use a boost-converter IC to do so.

[fede.tft] shares a flashlight built inside of a used glue stick case. It’s the perfect size for one AA battery (we’re always on the lookout for good battery cases), and a shape that we’re familiar with as a flashlight. The problem is that he wants two white LEDs but with just one AA cell he’s never going to have more that 1.5V available. He licked that problem, getting to 7.2V by designing his own step-up converter using one transistor, an inductor, and three passive components. To get the inductor he needs, a stock part is disassembled and rewound to suit. Maybe you just end up with a flashlight when all is said and done, but then again, the Sistine Chapel is just some paintings on a ceiling.

Getting Your Message Across At Commencement

June 8, 2010 by Mike Szczys 33 Comments

[Yomagaocho] is graduation from Northwestern University on June 18th (wow that’s late in the year… they must be on quarters). He decided to spice up his mortarboard for the commencement ceremony. A normal message wasn’t good enough, and even a solar-powered diorama wasn’t going to suit him. Instead he added 256 addressable LEDs to the top so that he can get his message across without being limited to a couple of words. See it demonstrated after the break.

He was nice enough to give us the technical details. The matrix is a 16×16 grid mounted in some laser-cut black acrylic. We immediately wondered about the display working in sunlight (a June graduation will probably be outside). He didn’t use any current limiting resistors with the LEDs, dangerous to the longevity but this should provide maximum brightness. It’s certainly a geeky concept, but having the ribbon cable that controls it trailing down into your robe might make those graduation photos a bit embarrassing a few years down the road. Continue reading “Getting Your Message Across At Commencement” →

Wire-wrapping An LED Matrix

June 3, 2010 by Mike Szczys 20 Comments

Regular reader [Osgeld] built a 1024 LED display matrix. This is a proof-of-concept design and he admittedly has overloaded the components. Most notably, the 595 shift registers (featured over the weekend) are sourcing too much current if all eight pins are active. That’s easy enough to fix in the next design by moving up to cascading LED drivers. Instead of soldering every connection in the display, [Osgeld] soldered the components in place and then used wire wrapping to make the point-to-point connections. This must have saved him a ton of time and frustration. We can’t wait to see what comes out of this first prototype.

Six Digit LED Clock

June 2, 2010 by Mike Szczys 13 Comments

Got a bag of LEDs handy? Why not build a display with them? We’ve seen a lot of clocks that make use of LED modules but soldering your own is a fun pastime. [Vadim Suhovatih] did just that using 130 LEDs to build this clock. Each segment of the 7-segment digits consists of three LEDs in parallel which are switched by some 2N4401 transistors. An ATmega328 in the form of an Arduino controls the device with the aid of a DS1307 real-time clock for timekeeping and a 4017 decade counter to assist with scanning the display. Check out the demo after the break.

Continue reading “Six Digit LED Clock” →

Switchmode LED Flashlight Upgrade

June 1, 2010 by Caleb Kraft 11 Comments

When [Neelandan]’s cheap flashlight’s internal rechargeable battery died, he scrounged for a replacement. Ultimately, the brightness of the light suffered with his new battery, taken from an old cell phone since he had dropped the voltage a bit. Upon inspection he saw that he would have to swap the individual resistors for each lamp to get the desired brightness again. This wasn’t really acceptable as he would have to repeat the process if he used another re-purposed battery with different specs. Instead, he added a new circuit to supply constant brightness until the voltage drops below 2.7 volts. We love to see hardware resurrected, even if it is just a cheap LED flashlight.

May The Phorse Be With You

May 31, 2010 by Jakob Griffith 23 Comments

The PhorsePOV by [Julian Skidmore] almost slipped by, but we thought it was a nice easy hack for your Memorial Monday. The gadget uses an ATTINY25 to drive 6 LEDs aren’t standard characters 7 units high? Which when waved in the air produces a readable message. What we were really interested in is the use of a single button for text entry, called Phorse code, or an “easier to learn and remember” version of Morse code. While it seemed silly at first, most of us here could enter messages within a few minutes of trying.

32 LED POV Globe

May 19, 2010 by Caleb Kraft 26 Comments

[youtube=http://www.youtube.com/watch?v=bt1UEGD3BDk]

Here’s a slick version of a POV globe(google translated). Created by [Riko], this globe has 32 LEDs and is powered by a rotating coil. The layout looks fairly solid in operation, with the POV effect showing up very nicely on camera. You can get the schematics and source code from the project page.

We found this project, just like the previous fantastic LED globe on HackedGadgets.com. Apparently someone linked to this project in the comments. That is fantastic, that is what the comments should be for. Please help keep our comments polite and helpful as well, even if you are just linking to a project that you think is better.