Trying to load GPS_AT_cmd application through DevStudio, the loading process reached 99%, after which, the process is blocked. Now the module only sends through serial port 1 a strange character (0x15 in exadecimal format) every one second. It not responds to AT commands. Is there some recovery procedure that can I do?
0x15 is part of file transfer protocol (X-Modem) which used to download the OpenAT application from host to Q2698.
Can you please try and send “AT+CFUN=1” to Q2698 and see if it can back to normal?
I’ve sent AT+CFUN=1 but with no result. Q2698 remains in sending the 0x15 character and it doesn’t respond to any AT command.
5 minutes after switching on, Q2698 sent through serial “*** TIME OUT ***” and break sending 0x15. But it still doesn’t respond to any AT command.
These are the steps I need to do to be able to communicate with the q2698 device:
-1: Power on Q26-DevKit (at this point, if I send AT commands, q2698 doesn’t answer)
-2: Reset 5 times q2698 through Reset Button (now q2698 answers the AT command, but it answers OK only at AT raw command. For all the others AT commands (AT+WOPEN, AT+IFC, ATI, ATI3 etc…) answers are ERROR.
at+wdwl +WDWL: 0
-3: Now I’m able to download firmware through X-Modem
-4: At the end of the downloading process, sending AT+CFUN=1, q2698 enters in a strange state, it doesn’t answers at any AT commands and I need to restart from point 1 to be able to communicate with it.
Reseting 5 times the module is used to force the module to enter in download mode (in this mode, we can used only few AT commands). You shouldn’t use this mechanism, the action is the same as executing the AT command AT+WDWL. These 4 steps are excepted.
Normally, you could download with dev studio. If you can’t, you can also download using hyperterminal or other terminal which support 1k-xmodem protocol.
The steps are:
- executing AT+WDWL
- wait for the characters (some terminals are filtering this characters)
- downlad with 1k-xmodem protocol
- isssuing AT+CFUN=1
What is the current status of your module ? Are you able to communicate with it ?
I’m able to communicate with module only if I reset it 5 times.
I think you have downloaded an openat application which resets the mdule in loop. What happened if you let the module running (I mean without any resets) ? Do you see any USB port mounted ?
if I let the module running, I can’t see any USB port mounted on PC and I can’t communicate not even through serial port.
After the fifth reset, I can communicate through serial port, I can see an USB device connected but driver is not recognized and COM port is not created.
Thank you all,
I’ve loaded another application on q2698 and now it’s works fine.
The problem was the application I’ve previously loaded which resets the module in loop.
It’s a GOOD idea to put a small startup delay at the beginning of your app to give you a chance to send an AT+WOPEN=0 command for exactly the reason you’ve just found out.
Have a look at the links referenced here or search the forum for “Startup Delay”.
Good to hear that you got it sorted.