I'm giddy to announce that I'm about ready to send my first ever PC board design out to BatchPCB! I've always wanted to make an Arduino shield and after reading all the posts on how to drive LEDs or make an aquarium light system, the idea finally came to me to build a power LED driver shield.
The power LED shield will be of specific interest for: aquarium owners, indoor growers, entertainment lighting, high-efficiency indoor lighting, bike headlights, nocturnal robotics :-? and the usual hobbyist and enthusiast crowds.
While I may sound like I'm already almost done with it, I'd really like to hear if anyone has ideas, feedback or suggestions on features that I might be able to add before having the PC board fabbed.
Once I do some more verification on the schematic and board design, I'll post pics.
Here's a rundown of the current features:
o Duemilanove (and Mega?) compatible
o Up to 4 driver channels, individually addressable via 4 Arduino PWM pins (3, 9, 10 and 11 on the 2009), any combination of colors.
o Buck (input voltage higher than LEDs), Boost (input voltage lower than LEDs) or a combination of driver types
o Max output manually adjustable from 50mA to 1A per channel, constant current
o Full opto-isolation to protect our precious Arduinos
o Optional 5V regulator to power the Arduino from the shield
o Easily drive 115 watts of LEDs from one shield (8 LEDs x 3.6 watts x 4 channels)
o Stackable for EVEN MORE output per channel. :o
o Input voltage range 5-32 VDC
So far, future improvements and ideas already include:
o Set max output current and perform analog dimming in software with a DAC circuit on each channel.
o Library that allows changing the PWM frequency easily (not necessary if I can do the DAC idea above)
o Serial option to allow zillions of channels without eating up pins.
o Mega-specific shield with more channels on more PWM pins. (I don't have a Mega yet)
Lemme know what you think!
EDIT: Misstated the output wattage at 156 watts. wooops!