RE: MQTT and GPS concurrent mode on Thingy:91

Martin Lesund — Fri, 28 Feb 2020 10:13:35 GMT

Hi Maciek,
I am very sorry for the delay.
First, I recommend upgrading to:

NCS v1.2.0 and MFW v1.1.1.

I recommend that you do not have everything in your main function.

You should have separate threads for the MQTT and GPS in your application, and both sockets should be read/polled all the time to avoid any conflicts.

I would recommend that you get the GPS fix before turning ON the LTE modem.

note: You can wake-up from PSM mode whenever you want, (and you do not need to disable PSM mode after a fix).
- GPS can also be running in eDRX intervals when the modem is in RRC IDLE mode.

It will be released an updated sample in NCS that shows this much better, so if you can wait a bit I would recommend looking out for that sample.

You can also utilize A-GPS now which will give you a much better TTFF on a cold start of the GPS. (this is showcased in GPS sample)