Hi there,
I’m putting the L76 GNSS module into STANDBY mode periodically for power saving. It will be waken up by a HOT START serial message when needed. However, after have the device running for around 3 days, at some point the GNSS module will fail to wake up from STANDBY mode.
To deal with it, I modify the software from my side to power it off for 1 second, if GPS time hasn’t been updated for more than 10 minutes.
It works for most of devices, but for some testing units I used frequently, it can still fail to wake up the L76 module even by power cycle it.
I’m wondering what’s the reason for L76 module not being able to wake up from the STAMDBY mode occasionally, and will it be fine to cut the power down directly, or is there any commands available to reset that module?
Thanks for your help, looking forward to your response!
Hanqi
Hi @Hanqi_Shao
Please use the “$PQTMVERNO*58” command to check the version of the module and let me know.
Hi George,
I can still see the issue happening but with a really low possibility (~ 1/4000).
Once the GNSS is detected not being able to wake up from STANDY mode by sending “$PMTK101*32\r\n” to it, Its VCC will be disabled via Power Supply unit, wait for 1s, then enable the VCC again, but GNSS still can’t back to normal working mode.
Hence I sent the command you shared before, and got the response “$PQTMVERNO58PMTK60531”
Also sent the command “$PMTK60531" to get its firmware version, the reply is: "$PMTK705,MT3333_AXN5.1.9_MODULE_STD_F1_P1,0007,Quectel-L76L,1.008”
Additional info:
$PQVERNO,R,L76LNR03A01S,2020/03/02,00:49*28
Would you help with the this issue so that the GNSS module can also go back to normal working mode successfully? If a reset is required it’s still fine. I would like to have a reliable reset method when WAKEUP command doesn’t work.
Looking forward to hear from you!