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GPS "Static Navigation" and "Constant Navigation" — Parallax Forums

GPS "Static Navigation" and "Constant Navigation"

LevLev Posts: 182
edited 2013-10-05 17:40 in Accessories
This is from the Learn page:

[With the increasing number of GPS units being used in mass transit and consumer vehicles, the manufacturing companies have changed the output of the GPS modules to what is referred to as “Static Navigation”. With this output, the vehicle has to be moving at a pre-determined speed for the GPS to update its Lat/Lon data. What this does is it prevents your GPS from uttering the infamous “re-routing” every five seconds while sitting at a stop light. While this mode is good for vehicles, it is not so good for a DIY ground-based robot that moves at a mere 3 mph.

Fortunately for us, the GPS Modules also have a mode called “Constant Navigation”. This mode has the GPS-output updated Lat/Lon data every second, which is the refresh rate of the modules themselves. This means that you can power on the module at your desk, and watch the data change ever so slightly, without ever taking a step. Now, even the smallest robot moving at 0.5 mph can have on-board GPS navigation! ]

Apparently, as I understand it, the constant navigation mode requires reconfiguring new GPS modules using a fourth wire (blue one). I have not done this in the past. Does anyone know how to tell which modules default to the new Static Navigation mode, and which run by default in "Constant Navigation" mode? I wonder if there is a date or code that distinguishes the two.

Comments

  • Chris SavageChris Savage Parallax Engineering Posts: 14,406
    edited 2013-09-30 09:03
    All GPS Receivers I have seen, such as those sold by Parallax come set for Static Mode by default. I think this has been the norm for some time so you probably won't come across a new receiver set for Constant Navigation by default.
  • CircuitsoftCircuitsoft Posts: 1,166
    edited 2013-10-01 17:05
    I certainly see "Constant Navigation" mode default on the Skytraq modules I've used.
  • Nick ErnstNick Ernst Posts: 138
    edited 2013-10-02 08:42
    Constant Navigation mode may be default on some GPS modules, but as far as the PMB-648 and PMB-688 go, the default mode is Static Navigation. There are some GPS units that have these two modes broken out, and are easily switched between with the state of an I/O pin being high or low. The purpose of this project was to simply show people how they could modify the two modules that we currently offer to operate in the more preferred Constant Navigation mode.
  • Chris SavageChris Savage Parallax Engineering Posts: 14,406
    edited 2013-10-02 09:11
    Circuitsoft wrote: »
    I certainly see "Constant Navigation" mode default on the Skytraq modules I've used.

    It occurred to me that pretty much all the receivers I have worked with in the recent past have all had SiRFstar chipsets.
  • Phil Pilgrim (PhiPi)Phil Pilgrim (PhiPi) Posts: 23,514
    edited 2013-10-02 09:21
    As a side note, setting the PMB-648 to Constant Navigation mode is not necessarily permanent. Some have reported the unit reverting to default settings after being powered off for awhile. So it's always best to reconfigure the device every time at power-up.

    -Phil
  • LevLev Posts: 182
    edited 2013-10-05 17:40
    Thanks everyone for your very helpful comments.

    Rich
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