hello,
I have a problem with an HL7800 modem. In AT modem, I have:
at
OKati3
HL7800.?.?.?.0
OK
But ATI9 does not reply. So, I tried to update either from UART1 or UART0, but I get only :
What might be going on ? How can I bring the modem back?
Thanks in advance
seems your COM port has data corruption.
You might try lower baud rate and see if it works
Hi Joao
Is the HL7802 attached to your host computer via USB or UART? (my guess is USB)
Are you certain that COM15 is the HL7802 port?
It looks like you are using a windows host computer? I had similar problems which I think are caused by Windows driver issues which I was unable to solve. I changed to a Linux host computer and was able to successfully flash the HL7802
Hi John and jyijyi
Thanks for your reply!
I am using a windows host computer. I attached the modem via UART and not USB
I tried another one-click uploader to version 4.4.6 and I succeeded. I tried 4.6.9.4
edit:
I still have the same problem as before even after a “successful update”. Any idea on this?
On the Debug Uart I get for the command “ver”:
ver
Core : RKAPP_02_01_02_00_80__b8247bc6f15eaf43cfdf7605486de028995374aa
Package : N/A
Chip Revision: TG-D0 (4)
SWIVer : N/A
Flash Info : ID 0x20bb18, Size 0x1000000
Thanks
Do you mean HL7800.4.4.6.0.exe is working but HL7800.4.6.9.4.exe is not working ?
If so, you can extract those two exe by 7zip, inside there is a sft.exe for FW downloading.
You can use the sft.exe in 4.4.6.0 to 4.6.9.4, after that you can upgrade by:
sft.exe -p COM15 -B 115200 -b 115200 AppFW_flash.bin sysHeader_backup.bin.alt1250 sysHeader.bin.alt1250 sysHeader_modem.bin.alt1250 u-boot.bin ue_lte.fw partmap.bin ue_lte.fw2
What I mean is that even with HL7800.4.4.6.0.exe being able to run the whole update, the module still has the same problem of not responding to ATI9 and it answers HL7800.?.?.?.0 .
Other modules, update normally.
so this is only happening on one module?
Exactly,
only this one. We have had many boards running with this module for a long time. This single one stopped working after some time in test and when I checked the modem, it was like that ( not knowing its version). I also tried to read the ICCID through AT+CCID? and I also get error.
I guess I will suppose I have some failure during the tests or some other electrical issues. Or is there something I could try to bring this module back?
Thank you very much
you can capture the oscilloscope on TX /RX of the UART and see if there is abnormal behavior on the waveform
Thanks,
I just did it. Seems to be fine and the 1V8 is accurate too. Power supply is also stable at 4Volts.
BR,
How about do a nv restore command
AT+NVBU=?
+NVBU: (0-4)
OKAT+NVBU?
+NVBU: 0,00/00/00,00:00:00-0,BHL78xx.3.7.2.3.RK_02_01_01_11_85.20191030
OKAT+NVBU=1
ERROR
Just as I saw the example in the document, I tried the following but nothing really changed in the module
AT+NVBU=1,3
OK
Then I tried programming the firmware again, with no success. 
how about AT+NVBU=1,0
It also didn’t work
… and eventually, I had an error in the middle of an upgrade attempt and now I get :
Nothing to upgrade…
Un-Protected 4 sectors
Un-Protected 4 sectors
Erasing Flash…
Erased 4 sectors
Writing to Flash… done
Protected 4 sectors
Protected 4 sectors
ERROR: 00000008
ERROR: 00000008
do_halt…
0
Version: 2.0
Try upgrade via uart0
