ATtiny84 Intake

Hi, I'm using an ATtiny84 in a transceiver circuit. I plan on running it off of a 9 volt battery using a 5v regulator, but I was wondering if it matters how much current is coming in?

I guess I really want to know, if you attach a component to a battery, will it only draw as much current as it needs or are resistors needed in between (assuming th voltage matches)

The supply only needs to be able to provide the stated current or more - as long as the voltage is right, it will draw whatever amount of current it needs.

Worth noting - Some older wallwart power supplies aren't actually regulated, and the voltage varies wildly with load - check voltage coming out of unknown wallwarts before you use them.

Thanks!

CantSayIHave:
Hi, I'm using an ATtiny84 in a transceiver circuit. I plan on running it off of a 9 volt battery using a 5v regulator, but I was wondering if it matters how much current is coming in?

The downside of using a regulator to drop the 9V down to 5V or 3.3V is it wastes power and I assume as your running it off a battery that power is important. Also if the 9V battery is a PP3 type then they don't deliver much current. You might be better off using 3x/2x 1.5V batteries and no regulator.