How "fast" could GPS data be refreshed while moving and does it depend on the mcu?

Question

I'm using Nano Every and SIM33EAU GPS module for my project and today I went riding shotgun to test how it works when moving on the road. I am using u8g2 library and one of the things that I have printed on the screen is gps.course.deg - which is as the name suggest, course of the GPS module's movement in degrees.

Next to my Arduino device I had a phone with some compass app, and the course was somewhat correct while we were moving at normal traffic speed, but the update rate was vastly different and I don't know why. The only "delay" in the sketch I have is this;

 if (gps.location.isUpdated()) 
 {
 Serial.print(F("Lat Lon = "));
 Serial.print(gps.location.lat(), 6);
 Serial.print(", ");
 Serial.println(gps.location.lng(), 6);
 } 
 else if (millis() - last > 500)
 ...

I wasn't able to check the Serial Monitor as I didn't have a laptop, so only reading from GPS module was what was being printed on the small OLED screen. So is the lagging update something on the GPS module side and how it works, or is it perhaps OLED not being able to refresh?

• jsotola: why are you asking for people to guess about your problem? ... this site is for providing answers, not guesses, so please ask a clear answerable question and include all information that you have

Answer 1

GPS modules deliver position updates in very different frequencies, depending on model and configuration (where changeable). Cheaper modules only provide an update every 1 second, while better ones have 5 or 10 Hz position update. Check the documentation for your module to get that information.

Additionally, it is of course possible to "cheat", by calculating an extrapolation, using the last position, direction and speed. Since speed and direction don't typically change very quickly, that works quite well and can give position updates at arbitrary rates.

• Varonne: thanks @PMF I figured there had to be some internal limit, for some reason I thought all the consumer level GPS modules like the one I have are "50Hz" ... obviously completely wrong. So the mobile phone cheats, or do they put top class gps modules in there?
• PMF: @Varonne I believe they cheat, but I can't tell you for sure. A "real" frequency of 5 or 10Hz is realistic even for decently priced modules. Downside probably is that they would use more power, which is also always a problem in cell phones. A top class GPS module that is used in professional navigation equipment is 15000ドル or so.