Racechrono QStarz 818XT reconfigure

edited July 2012 in RaceChrono for Android
I want to use racechrono with an external gps reciever (QStarz 818XT) on my android phone. I figure out, when i connect the gps reciever direclty from racechrono, my gps reciever reciever NMEA output settings reconfigured by racechrono. The modified settings:

Settings / default / racechrono
GSA / 1 / 5
ZDA / 0 / 5
RMC / 1 / 0
GSV / 1 / 5
VTG / 0 / 1

Racechrono work like a charm with these settings, but other software (like Bluetooth GPS mock provider) not (speed and time information not recieved furthermore).

If i want to use the reciever with other app (over "bluetooth gps" provider) i need to revert these NMEA settings to default (edmondo use the gps speed for calculation). It's very annoying.

Please implement the "revert bluetooth gps setting to default" or "not override gps settings" option. Thx


  • Hi Voji, I understand. I'll put that to my TO-DO list. Meanwhile you can revert the settings by pulling the GPS battery after using RaceChrono.
  • It's working, but every time i remove the battery, lost bt pairing information, agps, warm start, etc. I prefer to use GPSView to reset the default values (but without pc, your suggesstion is lifesaver)... Thx for your quick response!
  • edited July 2012
    One possible sollution of the problem (with minimal developement effort), when i stop the app, racechrono set the default nmea settings.(i don't know its possible, but sounds simple :)
  • aolaol
    edited July 2012
    That's possible, but I rather do not do that, as it's a bit unreliable. I would think the GPS is very often disconnected in forceful manner, by switching it off or goes out of range, so the settings would not be restored then. I will create a "Do not modify GPS settings" option. Of course in that case the 1 Hz MTK receiver will remain in 1 Hz mode ... :)
  • I'm also facing this problem.
    Using a MTK GPS-Chipset set to 10Hz, Racechrono will reconfigure it to 5Hz.

    Also my device uses RMC to get the timestamp for datalogging, so reconfigure the output sentences is also a problem. Meanwhile I "disconnected" the RX path in my controller firmware.

    question @aol: is it better to use GGA or RMC? What's preferred for RaceChrono?

    info@ voji: I think your problem is that navigation messages ae outputted more frequent than sattelite view and/or that RMC is disabled. I've got another piece of software which is confused by getting satview after five normal position reports.
  • aolaol
    edited July 2012
    Dani_Duke: Yep, I'll create an 'expert' option to disable this feature.

    It's preferred to have both GGA and RMC if those are the only choices. You could also use something like GGA+ZDA+VTG. RaceChrono also uses GSV + GSA for satellite info.

    Notice, you lose the DGPS support when you run MTK at 10 Hz, so the benefit is questionable.
  • Only just found out about this. I was already getting grey hair and thinking that there was problems with either my Nokia E90, E7 and my Android devices or my two Qstarz receivers, with them only working properly at random in any other app than RaceChrono.

    Why is there a need to change the configuration in the first place ?
  • aolaol
    edited December 2012
    marlow: I see how this can affect the other apps that you're using besides RaceChrono. I've probably got so few complaints only because most people don't use other software. Sorry for the inconvenience.

    The reason for doing this is to save bandwidth (=more reliable bluetooth connection) and turn the 1 Hz devices to 5 Hz. There is a setting on Android version (v2.11 or newer) to disable it, under the expert settings. Symbian version doesn't have this setting, but the QSTARZ and other MTK based receivers are easily reset to their default settings by removing the battery.
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