I'm currently working on an arduino sketch (EEPROM programmer) that receives serial data from a computer, then outputs data\address info through the I/O pins. However, I need one more I/O pin for the address bus... Since I'm only receiving data through the serial port, I was hoping that I could use pin 1 (TX) for digital I/O, but the Arduino wouldn't listen to my digitalWrite commands.
Is there any way I can use pin 1 in my project while still receiving serial data?
The USART has priority over normal pin operations when it's enabled. You can disable the transmitter by clearing a bit in USCR0B.
Go read the datasheet for more details...