Arduino Nano V3. Software serial on pins 20 & 21

Hi,

can I use the A6 & A7 (20,21) with software serial?

MartynC: Hi,

can I use the A6 & A7 (20,21) with software serial?

I think so. I'm using it on 18 & 19 without problems.

No. Please use the names A6 and A7, also in your sketch. To avoid any confusion.

The analog inputs A0...A5 are normal digital pins with extra analog ADC circuit added to them. The A6 and A7 of the ATmega328P microcontroller don't have the digital part ! they have only the analog ADC circuit.

You can use A6 and A7 as analog input and nothing else.

I stand corrected :-*

Thanks.

Wrong, A6 and A7 are infact analog only pins but can still be used as I/O. With external pullups and logic to decode the analog signal you can in fact use these pins as at least the rx equivalent pin. I am still testing out the drive strength of these pins to use for tx but will update soon.