Hi all, I am trying to build a standalone arduino. I am using a 9v 300ma wall power supply. In order to get this down to 5v I have connected it with a 7805 regulator I picked up at radioshack. The problem is, when I check the voltage with a multimeter, the output voltage is 8 volts! I then checked …

7805 Regulator with Standalone Arduino

fungus May 24, 2014, 5:28pm 4

Was there any load on it?

If not, put a resistor across the output and measure again.