What are the I/O pin numbers.Do even RX & TX can be taken for input and output for LCD's etc
Do even RX & TX can be taken for input and output for LCD's etc
Yes but you might not be able to upload code to the Arduino with some hardware attached to RX & TX ( that is pins 0 & 1 ).
What are the I/O pin numbers
On a Uno they are 0 to 19