GPS without PSM using external antenna on Thingy:91

RE: GPS without PSM using external antenna on Thingy:91

Martin — Tue, 07 Apr 2020 23:21:15 GMT

I tested at Swisscom and a lot of other places where PSM is not implemented correctly.
You still can get GPS signal but you have to wait till the network goes to the idle state.
For the Swisscom network this takes around 70 seconds. Other networks without PSM have the parameters set differently and for example Claro in Brazil (without PSM) goes to idle after 16 seconds.

So in this exampe where you just communicate every two minutes. With Swisscom you will be able to get around 40 GPS fixes and for the Claro example you get around 90 GPS fixes. Depending on your needs you can switch off the GPS early.

You can register for connected/idle events with 'AT+CSCON=3'.

RE: GPS without PSM using external antenna on Thingy:91

DurandA — Sat, 07 Mar 2020 13:07:10 GMT

I was never able to use GPS due to the unavailability of PSM. iBasis roaming in Switzerland never worked properly (it connected a few times but was never able to connect reliably) so I switched to a local provider (Swisscom). Unfortunately my local provider confirmed me that they did not enable PSM yet, so I am still waiting for it!

RE: GPS without PSM using external antenna on Thingy:91

zoheir — Sat, 07 Mar 2020 11:37:56 GMT

Hi DurandA,

Have you found any solution please , I have the same probleme in France no GPS at all .. !!

Best regards

RE: GPS without PSM using external antenna on Thingy:91

KarlPeters — Fri, 27 Sep 2019 14:21:46 GMT

What if I'm not using PSM or eDRX, device is continuously connected to network, but want to use GPS + NB-IOT concurrently. Is this possible? And if not, then why not? Thanks

RE: GPS without PSM using external antenna on Thingy:91

Yusuke — Sat, 14 Sep 2019 13:02:14 GMT

Let me confirm one thing. In the current firmware, you can't use eDRX and GPS concurrently, right?

RE: GPS without PSM using external antenna on Thingy:91

Sigurd — Wed, 04 Sep 2019 17:30:58 GMT

From the modem fw 1.0.0 release notes,

"- Support for simultaneous GNSS and LTE (M1 or NB1) system modes. GPS reception during
LTE Power Saving Mode (PSM) active periods."

But note that your provider might not support TCP(needed for MQTT) when in NB-IoT mode.

RE: GPS without PSM using external antenna on Thingy:91

DurandA — Wed, 04 Sep 2019 16:25:10 GMT

What about NB-IoT? Does the GPS work concurrently with it?

If I want to try it, is there any additional step after switching to the NB-IoT network mode?

RE: GPS without PSM using external antenna on Thingy:91

Sigurd — Wed, 04 Sep 2019 16:12:58 GMT

Hi,

The antenna itself is not related to this. As of today, when in concurrent LTE+GPS mode(AT%XSYSTEMMODE=1,0,1,0), the GPS can only be active in the PSM window. We will improve on this in a future release, e.g. allow GPS usage also in eDRX interval. But for now, if PSM is not supported by your provider, you can only use GPS in GPS/GNNS standalone mode.(that means if you want to use LTE to send GPS data, you will need to disconnect the LTE link, turn off LTE mode, switch to GPS mode, get GPS data, turn off GPS mode, turn on LTE mode and connect to the LTE network again. This is not implemented in the asset_tracker sample).