The up-side to this design is that all of the drivers are on-board, and only control signals are needed to manipulate the matrix. The down side is that his design requires 4 layers to route, and 4 layer boards are quite expensive to make.
I2C controlled 4X4 RGB LED matrix - [Link]
This blog demonstrates how to drive a bi-color LED, or any 2 LEDs, by using only one microcontroller pin. Sinking or sourcing current from the LED selects which one will light up. Setting the pin as input turns both LEDs off.
Alternating between 0,1, and high-Z, both LEDs are fully controllable and even dimmable. The article also explains how to calculate the resistor values to get the desired current for the LEDs. The only drawback to this circuit is that consumption will increase because the voltage divider requires current even when the LEDs are off. [via]
Driving a bicolor LED from a single output pin - [Link]
Having been disappointed by the generic offering of Christmas lights with small customization options, he decided to make fully customizable light decoration.
Small PIC12F609 MCUs along with RGB LEDs are placed on a board and daisy chained over a 3 wire cable. A master MCU is placed on one end of the cable and controls the color of the lights individually by sending addressed data over the wires. [via]
Christmas lights with a MCU in each bulb - [Link]
Don built an Amblight for his home theater PC. He put together this tutorial describing his build of a multichannel Arduino-based Ambilight. He estimates the BOM at $40 (in addition to the Arduino). [via]
The bill of materials include 6+ ShiftBrites (your call, I wouldn’t do less than 6 though), a printed circuit board, wire, and headers. Additionally this will require all of the components needed to get over 0.5 Amps at 5.5-9V DC on to the board to drive the ShiftBrites; this cannot be reasonably done over USB power. My ultimate goal here is to give others some ideas on how to go about this project for less money than it would cost to essentially buy everything in a kit. I went in to this trying to be resourceful and I feel pretty good about how it turned out.
DIY Arduino Ambilight using ShiftBrites - [Link]
To achieve a more aesthetic panel of your device, you can use flat top LED diodes Kingbright!
We´d like to focus your attention to well-proven flat top LED diodes intended mainly for indication on various controlling and indicating panels. In comparison to standard types with a half-ball top, these types offer a significantly more aesthetic solution when used in front panels.
Advantages / Features:
- aesthetic solution for front panels
- available in 5mm, 3mm and 2mm diameters
- very good visibility even from angles
- low power consumption
From the most used cylindrical types, we keep in stock types with a diameter of 5 mm, 3 mm, as well as miniature ones with a diameter of only 2 mm. All offered types have diffused plastic packages, thus they feature a good visibility even from high viewing angles.
Don´t let LEDs stand out of the panel - [Link]
Andrea Belloni writes:
We realized this project for the “Arduino Day” in Rome 14/04/2011. For it we used two JeeNode (Arduino variant with wireless module on-board), one Rainbowduino + RGB LED Matrix and one PC with Processing. The Processing sketch generate the “plasma” animation and sends the images stream to the first JeeNode via serial port. This JeeNode receives the images and sends it to the second JeeNode via wireless link. The second JeeNode receives the images and sends it to the Rainbowduino + RGB LED Matrix via i2c. More details on the blog’s post (for the English version scroll down).
Wireless pixels - [Link]
A very powerful and bright LED designed to be run on high current. Can be driven to 2800 mA and gives a light flux of 700 to 900 lm (400 lm at 1400 mA). Colour temperature 6300 K and beam angle 130°.
Available as a loose component as well as mounted on STAR PCBs.
Z-Power LED P7, 11.8 W – [Link]
An SMD LED for direct drive with 120/230 V alternating current. The LED consists of two separate coils which are connected in parallel at 120 VAC, and in series for drive with 230 VAC. Available in cold white and warm white versions with a light flux of 360 lm and 280 lm respectively.
230V AC Powered LED - [Link]
An app note on a LED brightness controller:
In this circuit, a digital potentiometer (DS1869) aids an LED-driver IC (MAX16800) in providing manual control of the LED brightness. The circuit also provides thermal protection against excessive heat and overload conditions.
LED brightness controller with 64 taps - [Link]
Giorgos Lazaridis writes:
Some time ago i uploaded a breathing LED circuit with the 555 timer chip. It became very popular and i received many comments and emails with people that made this circuit and worked fine, as well as comments with people that had troubles converting it to operate at 12 volts supply. It was designed to operate with 5 volts, because i plan to use it for a future PC mod. Since the PC power supply has 5 volts output, and since the LEDs that i plan to use require 3.8 volts to operate, choosing 5 volts for supply was the best choice to minimize power dissipation on the transistor.
Converting the original circuit to operate at 12 volts is not a big deal, but it requires some transistor knowledge. The only parts that should be changed were the biasing resistors R4 and R5. But i decided to take it one step further. I decided to make a more flexible breathing circuit. The new version as 2 more functions: It has an adjustable voltage oscillation amplitude, and an adjustable output DC offset. What this means is that it can be easily adjusted to operate with different LEDs. If for example the load is a 12V LED strip with operating voltage range 8 to 12 volts, the circuit can be adjusted to provide exactly this: 8 to 12 volts output. Similarly, it can be adjusted to operate with a high brightness LED that has voltage range from 2.4 to 3.8 volts.
Flexible 555 LED Pulsing (Breathing) Circuit - [Link]