Does pin 13 need a resistor?

OK, noob question here: I have a Duemilanove and a Pro Mini. Do both of these models have a resistor on pin 13? (I think so but I just want to double-check). If I plan on using a LED long term do I need a an additional resistor on pin 13 or can I use what’s there? (by long term I mean build a project, and have it run for awhile)

Thanks,

Jeff

Yes, I believe both of those boards have an led built in… if you plan to use the built in led, then a resistor is indeed built in.

Just to be clear, I’m not concerned about the LED that’s built into the circuit board - I will be connecting an external LED to pin 13 and GND.

if you plan to use the built in led, then a resistor is indeed built in.

So I’m still unclear. My question isn’t about the built in LED but rather hooking up an external LED up to pin 13. Do I need a resistor or will the resistor that’s built into pin 13 suffice?

Thanks,

Jeff

Pin 13 has a resistor and an LED, however the output from the Pin is the output from the processor so if you connect another LED to it you need an other LED AND another resistor, just look at the schematic.