HL7810 USB port disappear


I set the com port to the USB port via the UART interface.
Later, when I connected the cable to the USB port, all 3 USB com ports appeared, and I could also send AT commands.
But after a while, all 3 USB com ports disappeared, and no matter how I reset the module or reconnected the cable, the 3 USB com ports didn’t reappear.
Could anyone please help me solve this problem?
Many thanks.

can you see any port in linux?
Can you now type any command in UART?
Before your test, did you enable debug port by “AT+SWITRACEMODE=RnD” to have debug port in UART0?

There is no USB com port interface appear in Linux.
That’s too bad.
We didn’t send the “AT+SWITRACEMODE=RnD” command to enable the debug port to have the debug port in the UART before testing.

Can you now type any command in UART1?
did you see anything coming out from UART0?
Could it be the metal case problem in hardware?

Both UART 0 and UART 1 can send AT commands, but nothing responds after sending the commands.
We use the HL7810 EVB for testing.
There should be no hardware issues.

I have another question, can HL7810/7812 downgrade FW to version

i am not sure if you can still download FW to it as you cannot even do AT command communication

I have another module that sends AT commands to the UART interface and the USB port.
Is it possible to downgrade FW, I didn’t find in Sierra source that says FW can’t be downgraded.

i don’t see problem to downgrade through UART from to by exe file

We double-click on 5.4.10 FW in windows and see that the tool specifies the com interface error.
Causes the FW upgrade to fail.
Could you tell us why our tool could not specify to the right com port.
How should we modify this problem.

how did you do the successful upgrade in the past?

I remember you need to check %APPDATA%\HL78xx_download.ini for the COM port number

We haven’t had this problem with upgrading FW in the past, we just double-click on the exe file.

then i have no idea why suddenly it does not work on your environment

Does it open the right COM port?

We set the COM port to 12 in the INI file, but when we perform the firmware upgrade, it shows that the COM port we use is 11.
We checked to make sure that the settings INI file was brought into the firmware upgrade tool.

how comes they are using different COM port…

How about delete the ini file and do like this?

  1. open command prompt
  2. set DL_PORT=COM45
  3. set DL_BAUD=3000000
  4. HL7810.