Log data from UART0 and UART3

Hi there,

We would like to collect logs from HL78 in the deployed devices to be able to analyze them in case any connection troubles.

We use UART1 as the main port to communicate with HL78.

The datasheet shows that UART0 (Diagnostic Interface) can be used for this purpose.
But there aren’t any details related to UART3 (Modem Logs Interface).

The questions are:

  1. Is UART3 mandatory to get logs when UART0 is already used?
  2. Are the log information getting from UART0 includes the same log data getting from UART3?
  3. Is it possible to use 2 wire (RX, TX) connection for UART3?
  4. Are there any documents describing the log data structure and content getting from UART0 and UART3?


You need to use uart0 to get log

Thank you for your reply.
Could you please clarify what is data can be obtained from UART3 and would it be useful to analyze it in case of connection issues?

I don’t even see the physical pin in product technical specification…

This is from HL780x product technical specification:

i did not try this port before…
Did you see any output there?

BTW, you might need to see if AT+KHWIOCFG can configure these GPIO in your FW.

I don’t see any activity at UART3 pins

AT+KHWIOCFG? shows the following response:

+KHWIOCFG: 3,0,6
+KHWIOCFG: 4,0,8


Did you see any data output there?

Btw, why don’t you use uart0 to take log?