Download Arduino Mega Pinout I2C Gallery. The atmega2560p comes with builtin bootloader which makes it very easy. When cheaper boards are available, why go with arduino mega?
2 (interrupt 0), 3 (interrupt 1), 18 (interrupt 5), 19 (interrupt 4), 20 (interrupt 3), and 21 (interrupt 2).
I recently upgraded my shapeoko from an arduino uno to a mega and i am using a cnc stepper shield designed for the uno. The arduino uno pinout guide includes information you need about the different pins of the arduino uno microcontroller and their uses: What is the pinout of the mega? The arduino mega is a microcontroller board, based on the atmega2560p microcontroller by atmel.
