High Power RGB LED Shield
The shield name include RGB LED, however it is simple three independent LED driver shield. It is matter of how users want to use the shield. The shield can be connected to single or three strings of white LEDs, RGB strings or any LED strings. Each channel are independent, so any single or two channel can be used.
The shield is designed as an Arduino shield, however it can be used with any variants of Arduino or any microcontroller that support I2C. All functions of the shield are controllable with I2C which require 2 I2C and GND connection only.
When LEDs is operated at high ambient temperature or a small size of heatsink, the shield with temperature sensor can be useful. The current to LED can be dynamically adjustable depending on LED temperature.
You can order the shield from the store.
Any LEDs that have maximum current rating 350-1000mA would be suitable with the shield. The lighting-purpose power LEDs have normally higher than 350mA maximum current rating. These are the suitable LEDs for the shield.
It is recommend to have MCPCB (metal core PCB, normally called star-board) mounted LED than FR-4 PCB mounted LED, since MCPCB offer lower heat resistance. For multi-LEDs on single MCPCB, they are connected in series except RGB LED. For RGB LED mounted on single MCPCB, It is required to have all six connectors ( 3x anode and 3x cathode) separated. The shield will not work with common cathode or common anode RGB LEDs.
There are essentially only two different kinds of Power LEDs, 350mA and 700-1000mA LED. 350mA LED are normally un-branded cheap LEDs from Chinese manufactures. These are cost-effective and can be sourced from many places including Chinese website such as DealExtreme. They are cost normally less than $3. With larger quantity, it goes down to less than $1. Their quality is normally good enough for general use. Very long term stability (> 5 year) and exact specifications may be vague.
700mA LEDs are mostly come from reputable manufactures like Cree, Philips, OSRAM, SSC. They are available from big distributers like Digikey, Mouser, and Future Electronics, however only available as LED itself without MCPCB. Since these LEDs are mostly SMD LED, they are hard to mount at home. There are a few places where MCPCB mounted 700mA LEDs are available.
There is a post for some power LEDs in here.
Varieties of Philips Luxeon LEDs – single, tri-star, 7 LED MCPCB
Varieties of Cree LEDs, only place for Cree RGB LED in single MCPCB
DealExtreme have RGB LEDs, Cree Whites, and Cree Color LEDs. They are normally cheaper than other places
- 10W RGB LED http://s.dealextreme.com/search/500-Lumen+Multi-Color+RGB+LED+Emitter+Metal+Plate
- 30W RGB LED http://www.dealextreme.com/p/30w-1500-lumen-rgb-led-emitter-metal-plate-39960
Cree XR-E White ( brightness bin : R2 > Q5 > Q2 > P4 )
- R2 Bin http://www.dealextreme.com/p/cree-xr-e-r2-wg-emitter-on-premium-star-15943
- Q5 Bin http://www.dealextreme.com/p/cree-xr-e-q5-emitter-on-premium-star-228lm-at-1a-2394
- Q2 Bin http://www.dealextreme.com/p/cree-xr-e-q2-emitter-with-star-2395
- P4 Bin http://www.dealextreme.com/p/cree-xr-e-p4-led-emitter-on-star-black-4877
Cree Red, Green, Blue