Arduino lesson 3A advanced command processing

In lesson 3 we explore how to handle commands from the serial port in a better way, add real functionality by being able to read analog inputs and output to PWM and digital ports

Source code available on my GITHUB Repository

[brightside]

Hi Peter, great work with the arduino lessons! Thanks for sharing.
A bit of a jam with [digital] pins D0 and D1 which are set to digital pins 0 and 1 respectively.
Problem: pin state could not be changes.
Digital pins 0 and 1 are also RXD and TXD serial pins. Seems like they are unusable as OUTPUT pins if
there is serial communication going.
reference: