How many LED's from Mega 2560

Using Arduino LEDs and Multiplexing
7

It doesn't say you can add them. That is:

  1. <= 200
  2. <= 200
  3. <= 200
  4. <= 100
  5. <= 100

AND don't put more than 200 mA into the chip. :slight_smile:

I must admit that section looks pretty crazy if you can't add them up, but what does it mean by a maximum of 200 mA into VCC then?

It makes a certain amount of sense. If internally the copper traces can only handle 200 mA, then they are saying that you can't put more than 200 mA into the chip. Then they are saying that each port only handles 200 mA. Well, obviously, if the whole chip can only take 200 mA.

Here's one possible explanation ... MOSFETs can sink a lot more current than is applied on the gate, right? So if the pins are sinking, then they could sink 200 mA per group of pins, because the 200 mA doesn't have to come from Vcc.

But to source it, the current has to come from somewhere, hence the limit of 200 mA. Just a guess, maybe someone else knows more about it.