GPS Current Drain Values in OPS - nRF9160

[MJD093]

Hello,

We are currently designing a device that will use the GPS on the nRF9160, our implimentation will involve using sensors to trigger GPS measurements for the duration of the sensor trigger. From current version of the datasheet (v1.0), there are three values for the GPS drain. The value for single shot isn't possible for our implimentation as we require much more frequent samples than once every 2 minutes. The other two are 47mA for continous and 12mA for continous PSM. Are these measurements the accurate expectations of the current drain so long as AT%SYSTEMMODE is still set as GPS mode?

I would like to know a little information on the PSM version of the power drain. Is it possible for this to work while using the nRF9160 to run the application and process the data or is this intended for applications that utilise the nRF9160 as a simple modem whilst the main application is on a different MCU?

Are there any plans to demonstrate the PSM version of the GPS code in future releases of the SDK?

[Hakon]

Hello, it will be supported in the asset tracker in a future release, it's scheduled for the end of the month.

[MJD093]

Thanks for the reply.

Will this be part of the release that will have the ability to run both NB-IoT and GPS at the same time or are they to be released seperately, with this being a new repo tag?

Would I be able to get an answer to the other question about the current drain values?

[Sigurd]

MJD093 said:

Are these measurements the accurate expectations of the current drain so long as AT%SYSTEMMODE is still set as GPS mode?

They are accurate, but for continuous tracking with PSM, the GPS is active during LTE PSM/sleep intervals. Continous tracking will give you a GPS fix every ~1 sec. If you don't need a fix every 1 sec, you could set it to e.g. every 10 sec, and you will get lower current consumption. In the upcoming v1.0.0 release of the modem fw, GPS+LTE mode can be enabled concurrently.

MJD093 said:

Is it possible for this to work while using the nRF9160 to run the application and process the data

Yes, this is fully possible. This is one of the benefits with the nRF9160, it has a dedicated CPU for the application, the modem is running on a separate CPU.

MJD093 said:

Are there any plans to demonstrate the PSM version of the GPS code in future releases of the SDK?

Yes,but the feature will likely first be shown in the Thingy:91 SW example.

[MJD093]

Thanks you for the information Sigurd. I look forward to the next release