DIY RGB Aquarium Light Project

hi everyone,

i new arduino , still have pick 1 up.  know little electronics, can follow analog circuits, buts thats extent.  starting new project make 5 channel rg(bx2)+white 3w led aquarium lights.  looking have diy drivers using cat4101 chip , using tlc5940 can control each channel.

led's driven @ 700ma , know 0-4096 stepping on tlc5940.  control each channel individually, controlling overall duty cycle make ramp , down simulate sunrise/sunset.

can show me schematic how lay out circuit , how interface arduino board (which board need?).  looking hardware right now, coding come later.

thanks,
mike

the tlc5940 isn't match cat4101 because 5940 produces negative-going constant current pwm output whereas cat4101 requires positive going 5v pwm input. need use pnp transistor , resistor (or similar) convert each 5940 output.

it sounds me want independently pwm 20 channels. have considered software pwm instead, perhaps using shiftpwm library http://www.elcojacobs.com/shiftpwm/? need 3 74hc595 shift registers, cost less tlc5940, , drive cat4101s directly. wouldn't 4096 pwm levels, think find 256 more enough.

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