control 45 3w RGB leds

Other Hardware LEDs and Multiplexing
1

Hello everyone, i want to ask for your support and ideas.
By no means i am an expert in electronics, but i have a projet in mind an i would like to ask for your advice, please, i am looking the simplest way to solve it, and then see how should i continue.

The question:
i want to drive 45 rgb leds with an arduino, í´ve read about multiplexing, PWM , and that might be the solution, but it is late, i´m tired and i am looking some help from you guys-

The thing is as follows.

-i have a touch screen with different colors on it, maybe 2000, but the similar tones can be considered as one, reducing the usable colors at probably 200
-In the initial state, let´s say we are in the "red" color
-if a user touches the "blue" color on the screen, the fading time from "red" to "blue" is ten minutes.
-if another user touches the "orange" on the screen, the fading time from "blue" to "orange" is ten minutes again, an so on...

What components should i use to do this? it is just a project that i would like to know how it is done. Any advice will be great, explaining with simple words and maybe an example or a link.

Thank You!

2

If all your LEDs will be the same colour, all you need is 3 Mosfets ( one for each RGB ) that can handle the current.

then drive the gates of the Mosfets with PWM output from 3 of the PWM enabled pins of the Arduino.

The program will be easy to write once you have gone through the introductory examples and played a bit.

I am assuming you know how to detect what colour you are touching on the screen.

If not you could have 3 filtered photodetectors connected to 3 analog inputs of the Arduino?

3

...all you need is 3 Mosfets ( one for each RGB ) that can handle the current.

Make sure the MOSFETs are "logic level" (Vgs ~ 2V) meaning the Arduino can fully turn them on, otherwise you'll need drivers for the MOSFET gates or your MOSFETs will run hot.