Need help BPI-M1+ communication with Arduino Nano

Hello there guys. I am beginner to BPI and i want to connect (two way communication) Arduino Nano 5V to my BPI-M1+ but i need to do this using the GPIO because the Arduino will be more than 20m away from where my BPI will be (i was planing to use USB but the distance is way to far for it to work i guess). So my question is do i need to use logic level convertor or the GPIO of BPI is also 5V? Does anyone know any good tutorial about this kind of connection? i am fine with any kind of OS but i would prefer Raspbian or Bananian… Once i am done with the whole project i will share it here first with all the details so that others can make the same device. Thanks in advance and best wishes to all.