Arduino Context


Digital Pins   There are 14 Digital Pins, numberered 0 - 13.
Each can be 0 volts / 5 volts representing LOW / HIGH.
    They can be programmed to work as Input or Output.

Analog Pins   There are 6 Analog Pins, numbered A0 - A5.
By default these are Inputs.
    They accept a voltage in the range 0 volts / 5 volts.
and convert this to a (10 bit integer) number 0 - 1023.
(This is equivalent to a precision of 3 significant figures.)
    Six of the Digital Pins (3, 5, 6, 9, 10, 11) are marked '~'
and can alternatively be programmed for Analog Output.
    The range for Analog Output is 0-255.
This is 8 bits (1 byte).