UART on VIM3 Protocol and Voltage

Which Khadas SBC do you use?

VIM 3 Basic

Which system do you use? Android, Ubuntu, OOWOW or others?

Ubuntu 20.04

Which version of system do you use? Khadas official images, self built images, or others?

Linux kernel, Khadas official image

Please describe your issue below:

Hi,

I would like to use the UART pins 15 and 16.

  1. May I please know if they can use the RS232 serial port protocol?
  2. What is the voltage level on the pins?
  3. How many device can the VIM 3 control using the pins 15 and 16, can it control more than 1 device through the same port, if so may I please know how it is to be connected?
  4. Can pins 17,18, and 19 be used on the same protocol as pins 15 and 16?

Thank you