Internal GPS vs. BT-Q818XT

This discussion was created from comments split from: First time user help appreciated..


  • Hi all,

    I just installed RaceChrono in my Samsung S7 and tested with internal camera & internal GPS. It is working perfectly!!

    BUT, after that I had connected my Gopro 4 Silver to another test, and the video was fine, but internal GPS has registered only the first and last point, not all the circuit. I made also a test without camera, to check only the GPS and have the same result.

    Obs: I am using the phone on my pocket. Usually I use the phone as GPS in my pocket without issues, so I believe that it is acquiring sattelite signal.

    Does somebody any tip to use racechrono with this configuration (Gopro + Internal GPS inside pocket)??

    Thanks in advance,

  • aolaol
    edited July 2018
    Well the WiFi connection to GoPro could interfere with the internal GPS (that has already very low signal due being in your pocket). Usually internal GPS does not work from pocket, so I'd never recommend doing that. External GPS are not expensive, and will improve data quality, even if the phone was not in your pocket.
  • Just a note, internal gps rate on phones are very poor refresh rates in comparison to actual gps tracking devices. I'm pretty sure from researching myself, most if not all phones gps are 1-2hz (1× refresh per second)
    Opposed to GPS devices running 10hz (10× refresh per second) Which means much more accurate data.
  • Yes, the internal GPS are always 1 Hz. External ones are usually between 1-20 Hz. Also I’d recommend sticking with my recommended list (see the FAQ).
  • edited July 2018
    Thank you guys, I've already ordered a Qstarz bt-q818xt, but unfortunately I am in Brazil and will take loooooong time to arrive here. I did a test with gopro in my car with phone on the passenger seat and it works fine, so I believe that the problem is the pocket when riding my motorcycle.

    Lets wait for the external GPS unit to test again.

    Have a nice weekend!!

  • @MarceloArana yes, that's definitely the problem. The internal GPS will work much better with phone on passenger seat, than in your leathers. Although it's not the optimal place for the phone either.
  • Thanks @aol, I will make another test once external GPS receiver arrives and post the results.
  • Hi guys,

    So, finally my Qstarz bt-q818xt is here.... I made an quick test and... I am driving over the buldings... I was expecting that it would be more accurated than mobile's GPS, but the track is out of the streets...

    Do you have any tip?

    Thanks ;-)
  • aolaol
    edited July 2018
    Well, the QSTARZ is not the best external GPS, mostly because of lack of GLONASS and iOS support. But it should still be at least as accurate as any internal GPS, with added benefit of higher update rate and freedom of installing it independent from the phone. Just place it to location where it can see to sky from most of the directions.
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