Perfboard Hackduino (Arduino-compatible circuit)

Step 3 Voltage Regulator

LM7805 circuit goes next.  The 7805 allows you to power the circuit with a 9v battery or even 12v DC power supply, and ouputs 5v which is what our chip wants.  With the "chair" facing you, solder the 10nF capacitor connecting the right two legs of the 7805.  In this position, from left to right, the pins are input voltage - ground - output voltage (5v).

10nF cap (labeled 103) bridges the GND and OUTPUT voltage.