[Nightly, dev kernel, Orange Pi One] How to enable UART?

[Baller Chica]

Hey, 

 

I am trying to use the UART pins to talk to an external module. 

 

I tried doing this, shorted the RX and TX pins respectively (ttys0-ttys3)

screen /dev/ttyS[0-3] 57600 

 

However, I keep getting the message that screen is terminating. 

 

uname -a
Linux orangepizero 4.10.0-sun8i #14 SMP Fri Feb 24 03:02:58 CET 2017 armv7l armv7l armv7l GNU/Linux

 

Any help is appreciated. 

 

UPDATE: Got it working from a solutions from here

[Igor]

https://forum.armbian.com/index.php?/search/&q=How to enable UART