My device now works on the breadboard, with wires running to the Arduino. Now I want to wire the circuit up and install it. It's not a complicated circuit, so I plan to use perforated circuit board and soldering wires rather than making a printed circuit board.
What do I need to replace the Arduino in the circuit besides just the ATMega chip? I'm using the SPI pins and some of the digital and analog pins. But nothing like the USB port or the like.