Current Consumption - NRF9160

RE: Current Consumption - NRF9160

Sigurd — Tue, 12 Nov 2019 15:56:47 GMT

Hi,

Unfortunately, I don't have any estimate on how long time a cold-start GPS fix takes with 0.10.2 DK, but it should be better than the v0.8.5. It’s also difficult to give an objective answer that you can re-create, since there are several external factors that can affect the time it takes. E.g. if there are buildings, bridges, trees in the area, and the GPS coverage and the weather conditions you have in your area at a given time. As mentioned by Will, we will in the future release A-GPS, that should give time-to-first fix below 10 seconds.

The GPS will consume around ~40mA when searching for the fix, and once you get a GPS fix, you will typically turn off the GPS, and just start it in intervals, and then it will just take a few seconds(between 1 to 2 seconds) to get a fix again(hot-start).

RE: Current Consumption - NRF9160

phipi — Fri, 08 Nov 2019 14:22:16 GMT

Sigurd, can you give an estimate of what kind of current consumption over what amount of time we should be expecting to acquire a GPS fix from cold start on the 0.10.2 DK?

RE: Current Consumption - NRF9160

Sigurd — Fri, 08 Nov 2019 14:07:37 GMT

If you are testing this on a nRF9160-DK v0.8.5, then note that the v0.8.5 GPS front-end is not good enough to serve as a reference design. We have done a lot of improvements on the GPS front-end in the v0.10.2 DK reference design, that will give better performance.

RE: Current Consumption - NRF9160

Will Lizardo — Thu, 07 Nov 2019 23:03:20 GMT

Hi Phipi, I do not work for Nordic, so I can't speak on their behalf but currently, the GPS fix is taking 30s+.

I understood that the next fw would cover A-GPS and the same improvements, and the main expectation is to have a fix in less than 10s with a good antenna.

RE: Current Consumption - NRF9160

phipi — Thu, 07 Nov 2019 21:49:39 GMT

Thanks for the reply Will. Does this mean that it isn't possible with current firmware, and that the above response is in fact incorrect?

What kind of current were you able to get down to for GPS acquisition?

RE: Current Consumption - NRF9160

Will Lizardo — Thu, 07 Nov 2019 21:16:21 GMT

Hi Phipi, Nordic will release a new firmware that will improve the GPS performance and acquisition time.

I understood from my sales manager that this firmware would be available in two weeks time.

RE: Current Consumption - NRF9160

phipi — Thu, 07 Nov 2019 18:37:10 GMT

I know this is old, but I'm looking at something similar and this seems like a bit of a stretch to me. From what I've seen GPS can take anywhere from a minute (warm start) to 15 minutes (cold start) to acquire location and consumes about 50mA in the process. Assuming an average 5 minute acquisition time that's 4.2mAh per acquisition. With a 1000mAh battery that would be just 250 connections.

What am I missing?

RE: Current Consumption - NRF9160

Sigurd — Tue, 26 Feb 2019 13:00:30 GMT

Hi,

[quote userid="75423" url="~/f/nordic-q-a/44126/current-consumption---nrf9160"]Is it possible? [/quote]

Yes, this is possible. Let’s say that the customer need 200 days, that is 4800 hours. With a 1000mAh battery, that is 1000 mAh / 4800h = 208 uA avg current. Several of the scenarios listed here is then possible today. Note that we are now on the nRF9160 Engineering A version, so these current consumption numbers will actually be even lower with the production version in April.

[quote userid="75423" url="~/f/nordic-q-a/44126/current-consumption---nrf9160"]Do you have a spreadsheet that I can use the analyse the MCU parameters?[/quote]

There is currently no spreadsheet available.