I am in the process of designing a battery powered tracking solution using MC60. I noticed the GNSS has a periodic acquisition mode called AlwaysLocate. But the documents does not specify how and when the mode switching occurs and under what conditions. I would like to know what triggers the mode switching, is it based on the GNSS location and the relative speed? Or does the hardware have internal accelerometers? If it does, how to configure the triggering threshold. Also if it is a good mode to use in a low power, low range application?
What must be the GNSS workflow for such and application?
We don’t suggest using AlwaysLocate mode in a low power, low range application. Actually, we don’t promote AlwaysLocate mode as well because of its complicated algorithm.
Regarding low power application of MC60 GNSS, you could issue AT command AT+QGNSSC to shut down main power supply of GNSS part(so-called backup mode, only RTC and NVM domain has power supply, then the time and assistance data will be kept. A start in 2 hours is still a hot start ).
Please refer to AT commands in the link below:
Any questions, please feel free to let me know.
Thank you for your reply.
I am using the stand alone solution. What kind of workflow would you recommend for runtime power conservation in stand alone mode.
Also is the RTC shared among both GSM and GNSS parts? As in syncing the RTC using NITZ complement GNSS syncing the RTC?
Sorry for the delay.
The main difference between All-in-One mode and Stand-alone mode is the UART connection. The power supply of GNSS is still under control of MC60. So the workflow is similar.
The latter 2 questions, I need to confirm with R&D and keep you posted.
Thank you for your reply. Eagerly waiting for your reply on the other questions.
Regarding to the RTC, GSM and GNSS part don’t share the same RTC, they have their own.
Regarding to the time sync, please refer to chapter 3.2.3 of document Quectel_MC60&MC90_GNSS_AGPS_Application_Note_V1.2.
In stand alone mode, if I have VRTC ON, will the time that was synced (Both GNSS time and GSM Time that was separately synced) stay synced, assuming I cut VBAT for power conservation?
I added Quectel_MC60_Series_Hardware_Design_V2.0 refer in previous link.
Regarding to GNSS backup mode(RTC active), please refer to chapter 3.5.4. VRTC and VBAT both can be used as power supply of GNSS RTC.
Regarding to GSM power conservation, please refer to chapter 220.127.116.11 sleep mode.
If power supply of RTC domain is kept, the time stays synced.
I was making some researches about AlwaysLocate as there is no description in Docs, i’m facing the same question with Mr @webyfymad, would you please answer these questions ? the documents does not specify how and when the mode switching occurs and under what conditions. I would like to know what triggers the mode switching, is it based on the GNSS location and the relative speed? Or does the hardware have internal accelerometers? If it does, how to configure the triggering threshold? What must be the GNSS workflow for such and application?
does HDOP involve ? how could i get the HDOP value outside the GGA format !?
As I answered before, we don’t suggest using AlwaysLocate mode. You could use other modes instead, for example, Periodic mode.
That is quite unfortunate, one of the features promoted in the MC60 marketing presentation was this alwayslocate mode.
For power saving purpose, it’s not recommended to use the AlwaysLocate mode. While in other application scenario, it’s available.