andyopayne:
Hi Everyone,
I have a quick question. I'm hoping to create a small IR emitter (and detector) board using the Arduino Pro Mini 3.3V 8MHz board driven by a 3V CR2032 coin cell battery. I'm trying to make this as small as possible, which is why I went with the Pro Mini and coin cell battery. However, my concern is the current draw from a typical IR LED. As far as I can tell, this will draw around 50mA from the Arduino... which is more than each pin can handle.
No need to worry, the pins of your Arduino Pro Mini 3.3V are perfectly safe... a CR2032 will never be able to provide that much current. 