PWM lots of RGB LED's with a single PIC?

[Spadez]

Hi,

What is the best way of PWMing about 5-10 RGB LED's using a single 16f628A? I know the hardware PWM on is only a single pin which wont do for RGB and apparently its not great to use the software PWM because it cant do anything else in the background.

- James

 

[birdman0_o]

Will each of the LEDs be a different color? How many different steps do you want, 2,4,8 bit?

What language, ASM or C?

 

[Brevor]

Check out this guys web site, He posts here sometimes.
https://www.youtube.com/user/picprojects#p/u/12/YcDKxqUttUI

 

[Spadez]

Hi,

Every led will be the same colour. I'm not sure how many bits I need to be honest. Is that just how many colour variations I need?

I'll check out the link.

 

[Hippogriff]

If every RGB LED will be the same colour, at the same time, then I happily use a 12v RGB LED strip, connected to 3 pins of a PIC (16F628a or 12F863) via something like a ULN2003AN and doing software PWM... which is not so bad, really.

If you do want all the LEDs to be different colours at different times, then that's a different problem, but one I'd be very much interested in hearing how you resolve...

 

[StudentSA]

Good Day,
I used the software PWM implementation method. I utilised 3 digital IO pins of the PIC to control 3 N-Channel MOSFETS. one per color. The Pic only controls the MOSFETs which are responsible for driving the Load of LED`s.

It has worked very well thus far, the only thing I found esential was to use a 20MHz crystal so that the PWM can have a decent refresh rate.

If you would like my HITECH C code as a guide please PM me.