Jimmie P Rodgers . com writes:
The Open Heart is an LED matrix of individually addressable LEDs. It can be used to create a brooch or bag light with highly customizable animations. It can be configured so that you can temporarily attach it to fabrics with headers that you simply push through, or you can configure it to be sewn into a project using conductive fabric for a more permanent setup. [via]
Open Heart - [Link]
Smart Battery Meter meaures the charge condition of LEAD-ACID batteries and uses a multicolor LED array to show remaining charge.
The Smart Battery Meter measures the “state of charge” of a 12 volt or 24 volt sealed, lead-acid battery system. It uses a multi-color array of LEDs to give an instant visual indicator of the remaining charge, sort of like a gas gauge.
You can buy a kit or assembled unit from the site below. Instructions are not online yet, but you can email the author for more information.
Smart Battery Meter - [Link]
In this “instructable” jaycollett explains how he modifyed a tap light to delay about 3 minutes when pressed off.
After reading this nice tutorial I thought I’d post an instructable to show everyone how I accomplished making myself a few tap lights with a delayed turn-off. My wife always forgets to turn lights off and I knew I had to install these in our closets with a auto-off feature! For my setup I used the following parts, you can play with the capacitor and resistor to adjust the delay in turning off the LEDs. This setup will keep the LEDs on for about 3 minutes before they get too dim to be usable.
Tap Light LED Auto-Off Hack - [Link]
In this project “annacegu” intergrates the 4D TTL camera functionality onto the uOLED-xxx-G1(GFX) series LCDs. Apart from as a normal camera, it has various uses, such as a video intercom, a baby monitor, or as part of a security system. Check more details and .4dg file on the link below
uCAM demo with uOLED-xxx-G1(GFX) - [Link]
So there are a ton of instructables covering the use of high brightness leds. Many of them use the commercially available Buckpuck from Luxdrive. Many of them also use linear regulation circuits that top out at 350 mA because they are highly inefficient. This instructable serves to let people know that there are other options out there to drive high power leds.
1.5A Constant Current Linear Regulator for LEDs - [Link]
João Silva writes:
Some time ago I had the idea of building a LED lamp that was solar powered, harvesting the Sun during the day and charging the battery, while at night deliver some light. The idea was to extend the hours of light of my peppers during the winter, once the vase was inside the house. [via]
LED SolarLight - [Link]
A small ATMEL ATtiny13A microcontroller (IC1) is the brain of the circuit. One pin (PWM) blinks the lights, most of the other pins are used for programming and power. You could get similar effects with a 555 timer or discrete components, but our goal is to learn about a new microcontroller family and make something easy to hack. [via]
Hackable LED Christmas card - [Link]
This tiny circuit is a simple way to make a fading led without having to program chips or writing code. Just a few simple components and you’re ready to fade all day. The end result is a constant fade up and fade down just like a Mac on standby.
Throbbing / Fading LED with 555 Timer - [Link]
Step-by-step, easy to follow instructions on the building of a LED Rainbow RGB LED PWM Controller. Only a minimal amount of parts are needed, along with a PIC processor, and you can construct one of the most amazing LED controllers available.
The system is capable of driving either RGB LEDs, or individual Red, Green and Blue LEDs to produce stunning effects.
LED Rainbow – RGB LED PWM Controller - [Link]
Many people assume that all LEDs can be powered with a constant 3V power source. LEDs in fact have a non-linear current-voltage relationship. The current grows exponentially with the voltage supplied. There’s also the misconception that all LEDs of a given color will have a specific forward voltage. The forward voltage of an LED does not depend on the color alone and is affected by other factors such as size of the LED and its manufacturer. The point is, the life expectancy of your LED may degrade when its not powered properly.
Current Regulated LED Tester - [Link]