The AssetTrackerRK library now supports u-blox AssistNow! Most u-blox models including the MAX-M8 used on the AssetTracker V2 can greatly speed the time to first fix by using almanac, ephemeris, and location hinting data downloaded over the Internet instead of waiting for it to arrive by satellite.
Using my GPS indoors with some window view I can eventually get a GPS fix in about 215 seconds.
Using AssistNow, I can connect to cellular, get geolocation information from the Google Maps integration, get elevation information from the Google Elevation API, download the aiding data from the u-blox web site, upload it to the GPS, and get a GPS fix in 20 seconds!
The actual time to fix is only a few seconds after the aiding data is uploaded, but getting to the point where you can get the data takes some time since most likely if you cold start the GPS you’re also cold starting the cellular modem as well and that needs to have a connection to get geolocation information. The data usage is about 2.7 Kbytes per locate and download.
Works on Gen 2 and Gen 3 devices, including the Argon using Wi-Fi geolocation hinting. Works with u-blox GPS modules connected by serial or I2C as well. This includes the Particle AssetTracker V2, but does not include GlobalTop PA6H models like the AssetTracker V1 or Adafruit Ultimate GPS.