The digital pin 13 may blink as the bootloader flashes it everytime the atmega is reseted, and the digital pins 0 and 1 will vary a lot as they are used to upload the sketch to the board using the usb-serial chip.
The digital pin 13 may blink as the bootloader flashes it everytime the atmega is reseted, and the digital pins 0 and 1 will vary a lot as they are used to upload the sketch to the board using the usb-serial chip.