Using of UART on VIM3

VIM3
1

Hi all,
i’m a new user of Khadas.
I need to have an rx-tx communication with khadas to excange data with some other devices like ST arm micro-controller or sensors.

Until now I follow next steps:

  1. Flash eMMC with latest ubuntu desktop find here
  2. Follow this approach to open uart. In detail:
    2.1 I’m connecting using an usb/ttl converter to check connection, pin 15-16-17, as you can see
    photo_2020-12-09_15-08-12
    photo_2020-12-09_15-08-121280×589 78.5 KB

    2.2 I’m using PuTTY on windows to connect to instancied com3 but using on khadas command
    echo khadas | sudo tee /dev/ttyS0 or echo khadas | sudo tee /dev/ttyS1 nothing appear in PuTTY terminal. To be clear using ttyS1 in sudo tee command stuck Khadas until ctrl+c. In my dev I can find only ttyS0 and ttyS1
    2.2.1 Writing on PuTTY doesn’t have any kind of feedback.

Where’s my fault? Any suggestions?

Thanks in advance,
David.

2

Hello, Please try swapping the RX and TX lines. Tool TX to GPIO RX. Tool RX to GPIO TX.

3

@baldodavi From your picture, your TX and RX is reversed.

4

Main issue was the lack of ttyS3 now solved.
Now I can communicate with serial without any issue.

Thanks a lot.
David.

5

hello Mr baldodavi,
I also have same problem.
How did you activate your ttyS3?

6

Hi Denis,
I’ve observe a behavoir in my 4 months Khadas version: sometimes, during startup, there’s issues during establish connections between khadas and rest of the world, simply I reset khadas using hardware and issue was solved.

7

Thanks for your reply.

“reset” is different with “reboot”?
What is the “reset”? and how to do “reset”?