Arduino Hardware serial pins with RS485 I tried asking a question in my earlier post - SerialEvent with RS485 communication it helped me understand Hardware serial and Software serial but i had few more questions for which i started this new thread. Now i didn't write any code yet, but i will be using same code as my earlier post if i get expert inputs. 

My Project - I have 6 Arduino nano which will do some simple task, mostly its one way communication at a time, like once master send message to slave i don't want immediate response slave will push button or something and then it will send response to master. So its rare that i will have two way communication at same time.

RS485 - I am going to use RS485 as distance is around 40ft.

Now my questions -

1 - Can i use Hardware serial pins with RS485 for 40ft distance, i tested code and it does work but i couldn't test that for 40ft. So not sure if it works or not.

2 - Is it good idea to use hardware serial pins for my project i explained, as i see plus and minus over internet and making me confuse. I see majority people recommend Hardware pins though.

3 - Is there limitation connecting multiple arduino nano with this approach, i only did this with 2 so far.

I would appreciate your inputs, which will make me decide to go on right path. Sorry i didn't post any code because my post is more to understand correct path to be followed...
1 - Can i use Hardware serial pins with RS485 for 40ft distance, i tested code and it does work but i couldn't test that for 40ft. So not sure if it works or not.


Yes.


  2 - Is it good idea to use hardware serial pins for my project i explained, as i see plus and minus over internet and making me confuse. I see majority people recommend Hardware pins though.


Yes. SoftwareSerial is awful.


  3 - Is there limitation connecting multiple arduino nano with this approach, i only did this with 2 so far.


Yes. The MAX485 and similar chips can only handle up to about 30 devices on one bus. The exact number is in the datasheet for the chip.