Controlling lots of LEDs all doing the same thing.

I want to make 500-800 LEDS dance to my music and they will be RGB and I will have red as high and blue as mids and green as lows or something like that but, how do you hook all of them up running off a different power source other than the arduino, because the arduino only can handle 40 ma per PWM channel if I'm right and I'm going to be doing 16 amps per channel. Each PWM will have its color but I want to not have to have a bunch of shift resistors or something that will take a bunch of programing and will cause them to be out of sync.

So there will be red, blue, green coming each from there own PWM pin and needing them to run an infante amount of LED with the same programing as running one?

Also is it possible to have the arduino control the brightness of it but have a poteteometer control the brightest of all colours?

If this is possible I will be buying the arduino to run this but I want to know how much it's going to cost to see if the price is going to be way to much.

You can use MOSFETs to switch the LEDs, although 16A is quite a lot so make sure you look carefully at power ratings and heatsinks.

Get something described as "logic level" and the Arduino will be able to switch it from a PWM pin.

You could also look at LED strips. They save a lot of work. Some LEDs have built-in controllers (WS2811, WS2801) so you don't need any extra circuitry, just the strip, the Arduino and a power supply.

fungus: You can use MOSFETs to switch the LEDs, although 16A is quite a lot so make sure you look carefully at power ratings and heatsinks.

Get something described as "logic level" and the Arduino will be able to switch it from a PWM pin.

You could also look at LED strips. They save a lot of work. Some LEDs have built-in controllers (WS2811, WS2801) so you don't need any extra circuitry, just the strip, the Arduino and a power supply.

So I need a really fast switch.... Is what you are getting at. Sorry I haven't been working with this stuff very long and this could be my starter project.

A project that switches 16 Amps is not a starter project. Things do not scale up easly with electronics. You do not need a fast switch.

You will be meat if you split the FET drivers into just driving 1Amps worth of current each and feed them from the same output put through a 74LS04 buffer.

Grumpy_Mike: A project that switches 16 Amps is not a starter project. Things do not scale up easly with electronics. You do not need a fast switch.

You will be meat if you split the FET drivers into just driving 1Amps worth of current each and feed them from the same output put through a 74LS04 buffer.

"meat" (I know you're dyslexic but I don't get that one...)

Pay attention to Mike, he's a proper engineer. Amps are your enemy when you're trying to make reliable electronics. Splitting your LEDs up into separate blocks then using multiple MOSFETs is a good idea.

You can also raise the supply voltage then put groups of LEDs in series. eg. 24V can power seven 3.2V LEDs placed in series, or ten 2.2V LEDs. That lowers the amps a lot - each string of LEDs only uses the same amps as a single LED.

"meat" (I know you're dyslexic but I don't get that one...)

Wow iPad spell checker. What I actually typed was You would be better off .... How it got meat Jobs only knows. :)

"Wholesale - MOSFET 40N60 40A /600V TO-3P triode transistor Good quality ROHS"so then how many LEDs could I power with this?? And I would be running 110-120 volts because that's what I have here in Canada. It probably would be lowered to 50v so the amps could go up. I like the idea of upping the volts to make less amps each LED would be needed a 20 ma of amps and then I can string lots with 1 amp and 12-20 volts.

can the arduino run a pnp transistor using one of the PWM pins and using PWM?

Matcom1300: "Wholesale - MOSFET 40N60 40A /600V TO-3P triode transistor Good quality ROHS"so then how many LEDs could I power with this??

Not many. Those things get HOT. 40A can only be done in laboratories with an amazing heatsink.

Look for something like an IRL540 MOSFET, they're quite easy to buy.

Then google for "MOSFET with Arduino" or something like that. This topic has been covered about a million times already.

[quote author=Matcom1300 link=topic=183189.msg1357513#msg1357513 can the arduino run a pnp transistor using one of the PWM pins and using PWM? [/quote]

Sure, but it can be tricky ... and you don't need to.