Difference between revisions of "LED"

Revision as of 22:46, 10 December 2010

A light-emitting diode (LED) is a semiconductor light source. LEDs are used as indicator lamps in many devices, and are increasingly used for lighting. Introduced as a practical electronic component in 1962,<ref name=LemelsonMIT/> early LEDs emitted low-intensity red light, but modern versions are available across the visible, ultraviolet and infrared wavelengths, with very high brightness.

This page focus in driving LED's and RGB LED's using small programmable microcontrollers such as the [Arduino] platform.

Arduino LED's basics

• Arduino LED basics http://fritzing.org/projects/digital-output-loop/
• Arduino basic RGB LED mixer http://www.instructables.com/id/RGB-LED-Tutorial-using-an-Arduino-RGBL/step3/Example-Circuit/
• Arduino basic RGB LED mixer http://fritzing.org/projects/rgb-led-mixer/
• Arduino basic RGB LED mixer http://fritzing.org/projects/colored-light-rgb-led/
• Arduino power more LED's http://fritzing.org/projects/digital-output-npn-power-transistor/
• Arduino basic RGB LED strips http://fritzing.org/projects/arduino-controlled-rgb-led-light-strips/

LED's and RGB LED's Controllers for Arduino.

(most of the examples are compatible with other mricrocontrollers paltforms)

Arduino can drive LED's using its PMW Outputs (AnalogWrite). Considering we need 3 of them for each RGB LED's and the Arduino has just 6 PMW outputs one could think the maxium number we could drive are 2 LED's. Luckly there are a bunch of chips that can easily expand our Arduino PMW ports allowing us to drive a huge number of RGB LED's easily but also any other kind of devices that require these outputs as standard LED's or DC Motors.

TLC5940

TLC5940 is a 16 channel PWM unit, so you can drive 5 RGB's LED's. There's an arduino library to easy work with it.

• Datasheet http://www.ti.com/lit/gpn/tlc5940
• Library http://code.google.com/p/tlc5940arduino/
• Tutorial http://www.arduino.cc/playground/Learning/TLC5940/
• Tutorial (Shield design available) http://fritzing.org/projects/pwm-expander-rgb-ledsservos/

M5451

M5451 is a chip specially designed to drive up to 70 LED's . There's an arduino library to easy work with it that implements PMW support.

• Library http://code.google.com/p/arduino-m5451-current-driver/

• Datasheet http://www.ti.com/lit/gpn/tlc5940
• Library http://code.google.com/p/tlc5940arduino/
• Tutorial http://www.arduino.cc/playground/Learning/TLC5940/
• Tutorial (Shield design available) http://fritzing.org/projects/pwm-expander-rgb-ledsservos/

Packet solutions

Rainbowduino

Rainbowduino is a packet Arduino compatible soultion for driving RGB LED's

• Rainbowduino http://www.seeedstudio.com/depot/rainbowduino-led-driver-platform-atmega-328-p-371.html?cPath=93_99

ShiftBrite

ShiftBrite is a packet modular RGB LED. There's an arduino library to easy program it.

• ShiftBrite http://macetech.com/store/index.php?main_page=product_info&cPath=1&products_id=1
• Library http://www.arduino.cc/playground/Main/ShiftBriteLib

BlinkM

BlinkM is an RGB led packet together with an small microcontroller so you can control a huge number of RGB LED's over a single data bus. An Arduino could be use to communicate with the bus and control all the LED's

• BlinkM http://thingm.com/products/blinkm

DMX

Allow your Arduino to talk [DMX | http://en.wikipedia.org/wiki/DMX512] so you can manage stage professional LED lighting equipment.

• Arduino and DMX http://www.arduino.cc/playground/Learning/DMX
• DMX Shieldhttp://www.arduino.cc/playground/DMX/DMXShield
• Diagram on using the MAX485 chip http://fritzing.org/projects/arduino-to-dmx-converter/

Helpful links for programming RGB LED's

• RGB to Hex Conversion [1]