A 16mHz oscillator is mighty slow (about 1 cycle per minute) - 16MHz would be more appropriate.
All timings (including "millis") is based on the clock speed, so yes, you need a crystal.
A 16mHz oscillator is mighty slow (about 1 cycle per minute) - 16MHz would be more appropriate.
All timings (including "millis") is based on the clock speed, so yes, you need a crystal.