DanNixon @ instructables.com writes:
I just happened to see some large strips of LED lighting when I was picking up some parts at Maplin which were on sale (if I remember correct they were around £12 per approx. 2m strip) however the controller/driver was still around £40, so I thought I would just build a better one myself.
I wanted it to be a web enabled controller as there are a lot of cool things that can be done with a device once it is accessible over HTTP, and I am working on a home automation server project so it would be good to have some devices which I can test this with.
Arduino Web Enabled RGB Lighting - [Link]
Professor John A. Rodgers has previously taught us what the future has in store by way of flexible, stampable microelectronics that adhere to the surface of human skin. As revolutionary as those devices can be – providing critical health-related information from real-time physiological monitoring of the human body – they are limited in their ability to penetrate the depth of human tissue for an even greater understanding. A recent study by Rodgers and his team from UIUC alongside Professor Michael R. Bruchas of Washington University has found a unique solution to the tissue issue – injectable LEDs that can stimulate and monitor brain activity.
Studying the brain with micro-injectable LEDs - [Link]
No-name GU10 LED lamp teardown @ kuzyatech.com
In the usual Kuzyatech fashion, when something breaks, we must take it apart. Today, one of the ”early adopter” GU10 style LED lamps decided to fail mechanically.
No-name GU10 LED lamp teardown - [Link]
Write messages and show animations on this palm-sized heart-shaped LED display. Works seamlessly with Arduino, and requires only three pins to control. Want a heart matrix of your very own? You can buy this as DIY kit.
Heart Matrix display - [Link]
by Publitek European Editors:
With the proliferation of high-brightness LEDs designed to provide replacement lamps for commercial and domestic lighting there comes an equal, if not greater, proliferation of power supply solutions. With hundreds of products from dozens of manufacturers, it becomes a question of how to make sense of all the permutations of input / output voltages and output current / power ratings, to say nothing of the mechanical dimensions / termination types and the many other features for dimming, remote control, and circuit protection that are offered. This article aims to unravel the mysteries of the different types of LED power supplies and how they operate in order to ease the selection process.
How to Choose the Right Power Supply for Your LED Lighting Project - [Link]
The new iW3606 and iW3608 single-stage, solid state lighting (SSL) LED drivers from iWatt feature a wide, flicker-free dimming range from 100% all the way down to 1% of measured light, to closely match the dimming performance of incandescent bulbs. This enables the smooth, “natural” dimming, with no light drop-out at the low end of the dimming range and virtually no dead travel where the light turns off before the dimmer control reaches the bottom of its travel. The very low internal power consumption of the iW3606 and iW3608 allows them to start at a very low dimming level of <5% of light output. This virtually eliminates pop-on, a phenomenon where the light does not turn on at low dimmer levels and as the dimmer level is raised, the light suddenly turns on. This also helps eliminate popcorning effects, in which various bulbs in multiple-light installations on the same dimmer circuit can turn on at different dimmer setting thresholds. [via]
New LED Drivers Deliver Exceptional Bulb Dimming Performance - [Link]
A versatile kit that can be configured to drive either constant voltage LED arrays or constant current LEDs. Use the kit to dim under-cabinet LED lighting using flexible LED strips or build your own LED desk lamp using High Brightness LEDs.
The majority of the circuit is identical for both types of LEDs. Two inexpensive NPN transistors and a few resistors are added to the circuit for constant current LEDs. It uses the ability of a MOSFET transistor to act either as a digital switch or linear current regulator.
Constant voltage LED arrays include built-in current limiting resistors. Typically these arrays come in a flexible tape form (such as Jameco part number 2128631) but may also be constructed from discrete LEDs and appropriate current limiting resistors (for example a string of 3 white LEDs wired in series with a 120 ohm resistor designed to operate at 20 mA with a 12 VDC power supply). When configured to drive constant voltage LED arrays, the dimmer circuit acts as a digital switch that turns on and off hundreds or thousands of times per second to modulate the LED brightness.
Universal CC/CV LED Dimmer - [Link]
Raj from Embedded Lab posted a new PIC project which is about building a mono color LED matrix marquee that consists of 320 LEDs in total that are arranged in 8 rows and 40 columns. The project uses PIC16F1847 microcontroller which receives the display data from a PC through a serial interface, and display it on the LED matrix scrolling from right to left.
LED Matrix Scrolling Marquee using PIC MCU and Shift Registers - [Link]
Here’s an interesting project by Steve of Tangent Audio the AZIZ project, a microcontroller-based LED microscope illuminator:
AZIZ is an LED microscope illuminator that I designed and built from scratch. It is designed around a Texas Instruments TLC59116 constant-current PWM LED driver chip, and an Atmel ATTiny1634 8-bit microcontroller.
AZIZ: DIY LED microscope illuminator - [Link]