arduino will not run standalone

I seem to have issues running the arduino standalone.

i soldered up a circuit on a protoboard, as per the schematic found at

When i insert the atmega chip in the standalone board nothing happens. i measure the voltages on the power pins and read 5v the ground pins are ground

The crystal pins read .54v and .71v

is there any way to test the resonator that i am using?

Putting the chip back in my arduino usb everything works as normal.

If i power my standalone board from the arduino usb 5v line everything runs as normal, could noisy power be throwing off the arduino? any ideas?

What is your power source?

13.1v 5A switching power supply leading to a 7805 regulator. Used for RC car chargers. Probably a noisy source. should i put a capacitor from + to - on the 13.1v side and also the 5v side of the regulator?

A standard 7805 circuit shows a couple of filter caps, usually a .1uF and a 10uF, one on input and one on output. Check the datasheet for your particular flavor of 7805 for the manufacturer's recommendation.

when in doubt, throw a 0.1uF cap at it.


does your resonator have two pins or 3? Two pin units generally need external capacitors, 3 pin units don't.

i put a 10 uf capacitor between 5v and ground and everything works good now. must have been a noisy power supply