PINE64

Hi,
I am using ubuntu18 minimal LXDE image with my rockpro64.

I am using ttyS2 for UART communication. Have two doubts-
1) When i use 1500000 Buadrate, then it works fine. But when i change its baudrate to 115200 then after some time, my UART gives unexpected symbols but not correct data. So is ttyS2 should be used with 1500000 baudrate only?
2) I wanted to use ttyS4(UART4), But it is not working. Can i enable this?
Thanks.

Hi,
Please update as my important task is pending on same.
Can't i use ttsS2 with different buadrate such as 115200? I am getting garbage data in this baudrate.
Thanks.