Using USnooBie with Arduino
All you need to do is copy this text below into “/arduino-####/hardware/arduino/boards.txt”
Then just select the new "USnooBie" board from within the Arduino IDE's menus.
To upload a sketch, just activate the bootloader (press and release the reset-button while holding down the bootloader-activation-button, see the usage guide) and then press the "Upload" button in Arduino.
To know which pin is which, refer to the pin mappings of the ATmega328P.
Are you using PORTD2 or PORTD7? Remember, 2 pins are used for USB connectivity, digital pin 2 (PORTD2) and digital pin 7 (PORTD7) are already connected to the USB bus, see the schematic diagram of USnooBie. Using these pins can cause USB stuff to fail.