View source for Neo 1973 GPS

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Return to Neo 1973 GPS.

Personal tools

The Neo 1973 device contains an integrated GPS. The particular device is marketed as an AGPS, and there is some discussion available as to what significance that "A" might have.

The external antenna for the GPS is an MMCX connector. It is located inside the battery compartment, to the left of the battery, and directly above the SD card.

Note that the GTA02 GPS device contains the u-blox ANTARIS 4 ATR0635.

A critical problem with early (current) GTA02s is that they can take a long time (10min+) to get first GPS data. This problem has been traced to interference with the SD card, see this page for more discussion and suggested fixes.

Assisted GPS performance requirement also defined in GSM/GPRS 3GPP TS 25.171, CDMA 3GPP2 C.S0036-0

GTA01 GPS driver (gllin)

Main article - gllin

The GPS driver is available here: It is a command line tool that after starting writes the positioning data so that they can be read as if they were written to the file.

And here the Mail from Michael Shiloh

There was an effort to write a Free Software program that could be used instead of this binary-only program, but this stalled after the decision to change GPS chips in GTA02. The Iphone 3G also uses the same GPS chip. It's not inconcievable that this might lead to further effort.

See Hammerhead/Protocol for details and the latest status.

Some scripts for those with the binary are on Manually_using_GPS

Please see the important information on Gllin!


Main article: GTA02 GPS

To turn on the GPS, echo 1 to the file /sys/devices/platform/s3c2440-i2c/i2c-adapter/i2c-0/0-0073/neo1973-pm-gps.0/pwron

To read from the GPS, simply read /dev/ttySAC1.

gpspipe -r 2947

gpspipe is in package gps-utils

cat /dev/ttySAC1 

Produces the unknown msg*58 this doesn't happen with gpspipe

Before getting a fix, the GPS spits out lots of "$GPTXT,01,01,01,NMEA unknown msg*58", though these stop once a fix is obtained.

A position without a fix looks like:

  • $GPGGA,235946.99,,,,,00,00,5.0,,M,0.0001999,M,0.0020199,*57

One with a fix:

  • $GPGGA,065852.00,5613.022527,N,00306.725890,W,1,05,0.5,158.0,M,0.277000,M,-0.010


(central Scotland)

--Speedevil 11:52, 7 April 2008 (CEST)

If you are having GPS problems with your freerunner, please document these on the page GPS Problems. FreeRunner_GPS_antenna_repair_SOP documents a possible solution.

In Openmoko projects, you could find a GPS test program that could provide graphical and text dump of GPS information. This project called Openmoko AGPS UI project.

Possible GPS programs

As people develop more sophisticated GPS applications, please note them here.

Here are some ideas for possibilities:

  • Cairo-based mapping
  • Routing
  • Openstreetmap a map viewer, annotation, and editing system.
  • Pyroute is a routing program written in Python by Ojw, and a mobile phone GUI for maps, GPS, and routing.
  • Raná is the new version of pyroute
  • GPS-Trail a simple trail logger.
  • roadmap mapping system using freely available maps (US census TIGER, DGLib, shapefiles).
  • Geocaching paper chase for advanced users
  • Set Profile (Mute, etc.) to coordinates (ex. At work)
  • qpegps qtopia (arm PDA) based map viewer with gps features
  • Navit a car navigation system with routing engine.
  • TangoGPS works very well, downloads maps on demand and stores them for later use, very efficient.
  • QMapControl Qtopia based mapping widget. Displays maps and custom data, also other widgets can be bound to coordinates. GPS parser for the gllin output included.
  • collection of ideas
  • Cumulus GPS software for glider pilots (and pilots in general), has a port for Qtopia and pulls (world) maps from the KFLog flight planner project. I think someone has put a project like this on the projects website here.
  • Openmoko AGPS UI project.
  • GPS Sight, a popular Openmoko project under LGPL.
  • Orrery, an unpopular Openmoko project for displaying the night sky.
  • Gosmore is a routing and viewer of OSM XML data such as the planet.osm.

Using the Neo's GPS on a Laptop

  • First be sure you have gllin installed on the Neo.
  • On host type: nc -vvn -l -p 5000 > /tmp/nmeaNP
  • On the Neo type: nc 5000 < /tmp/nmeaNP
  • On the host PC install GPSD, your GPS is attached as /tmp/nmeaNP
  • start gpsd on host with: gpsd -p /tmp/nmeaNP
  • run your application! I used gpsdrive and it works better than my stand-alone GPS.
  • Tested with RoadNav.Works great!
  • With this in mind if you have an unlimited data package you could export this over the internet.
  • the possibilities are limitless.

Bluetooth GPS relay

To make your neo appear like a regular bluetooth GPS:


  • Power up the bluetooth radio
  • Run the gllin script
  • run sdptool add SP
  • run rfcomm watch 0 1 sh -c "cat /tmp/nmeaNP >/dev/rfcomm0" &


  • Power up the bluetooth radio
  • Ensure gpsd is running and the gps-utils package is installed
  • run sdptool add SP
  • run rfcomm watch 0 1 sh -c "gpspipe -r >/dev/rfcomm0" &