Maximum current draw through DIO port

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Originally Posted by Al Skierkiewicz

J,
When you speak of LEDs, many of us naturally think an LED string. A single LED can be switched by the DIO through a switching transistor or other driver. If your LED can operate (actually produce light) at 4 ma, you can sink that much current as quoted by Frank above.

We have a custom circuit that with a hall effect switch powered off from a DIO port. The circuit has a LED on it to act as an indicator when the hall effect chip has latched.