We all love blinky lights. What we love even more than blinky lights is a very detailed tutorial with great photos. [Richard Kline] has written this fantastic tutorial on how to build a large 5×7 LED matrix and control it with a PIC processor. The bulk of the body is a foam insulation board, covered with a diffuser. Source code and schematics are available for download from the site. If you’ve ever thought about getting into PIC processors, this would be a great beginner project.
[via MakeZine]
Reader [Osgeld] is a board-layout ninja. He populated this 4×4 LED matrix board without having a layout plan to start with. Watch it develop in slideshow format to see the art work he performs. The display is driven by a shift-register and he’s included all the proper parts like resistors and transistors, yet he makes everything fit. Why is this amazing? He’s using uninsulated wire and not a single one of them crosses another wire. He’s physically designing a printed circuit board, routing the traces as he solders away. He’s built this to use with an Arduino shift register tutorial and our only question is where is the header to hook this board to a microcontroller?
[Barry] didn’t want to deal with the voltages involved in using a Nixie display so he built this clock to look like it has Nixie tubes. He’s made 7-segment LED displays using some channel material, and mounted them so they look like they’re hovering above the clock base. Once everything was hooked up he added small glass jars over the top of each digit, completing the look.
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.
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.
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.
