GPS Lags well Behind Actual Location

Please provide the following information:

[ x ] FlightBox Kit
[  ] FlightBox Assembled (FB1X)
[  ] Generic Stratux

FlightBox / Stratux version: (V2.R1)

FlightBox / Stratux build: (? Installed in my RV-7A that's 60 miles away)

Radio Configuration:
[  x] Dual Band
[  ] Single Band - US / CA - 978 MHz UAT
[  ] Single Band - International - 1090-ES

GPS Configuration:
[  ] None - Using mobile device's GPS
[ x ] Open Flight Solutions Remote GPS
[  ] Internal GPS Module (VK-172)
[  ] Other:

USB Power Source:
[  ] USB Battery: (Make / Model Here)
[ x ] Cigarette Lighter Adapter: (??)

USB Cable:
[  ] 3' heavy gauge cable included with FlightBox
[  ] Other: (Make / Model / Description Here)

EFB Application name and version: FlyQefb 4.5.1

Please include a detailed description of your issue or question:
My Flight Box works fine except the aircraft picture on my IPAD Air running FlyQ efb lags well behind my actual location. It does the same when running WingX. Does anyone else have a problem with this? It is really a safety issue when viewing traffic that may be near by. My Garmin GNS-480 shows my accurate position. Anything I can check?

Also have the AHRS and a Serial Out USB cable.

That’s a new one. I’ve seen the GPS accuracy drop off on occasion, but I’ve never seen any kind of delay. The way the system works, it’s kind of hard to imagine where the delay would occur.

We read the data from the GPS on a dedicated thread. That thread parses the info and passes it to the GDL-90 writer which generates an ownship traffic message which is then sent out by the network functions within the app. There’s really no place to queue up the data, which is what would usually explain a delay.

The data is sent across the network using UDP (a kind of lightweight protocol that doesn’t include any facilities for queueing or retransmission).

If it arrives out of order (i.e. it’s older than some other packet that arrived before it) the apps should recognize that and toss it out.

Three questions:

  1. Do you have ADS-B Out?
  2. Do you know if the GPS on your FlightBox is getting a good signal?
  3. Do you have the Mode S address for your aircraft set in the Settings page?

There’s a small possibility that the onboard GPS isn’t getting a lock, but if it is intermittently seeing your ADS-B data (either directly from your Out or, more likely, from a ground station) then it’s using that position information (which is delayed).

If you do have ADS-B Out, and if you do have the Mode S address set, you can test this by simply replacing the mode S address with F00000 - that would force the system to use the FlightBox’s own GPS value regardless. If you app tells you it’s not getting a position (or if the icon stops moving altogether) then there may be an issue with the GPS on the FlightBox.