Ublox GPS Configuration for Tau Labs FC

Edouard Lafargue edited this page Mar 24, 2015 · 10 revisions
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Current TauLabs code is able to autoconfigure UBlox GPS units, irrespective of their initial configuration, including baudrate as long as the default baudrate of the GPS is 2400, 4800, 9600, 19200, 38400, 57600, 115200 or 230400.

In the ModuleSettings UAV Object, just double check that ModuleSettings/GPSAutoConfigure is set to "TRUE", speed is left to the default 57600 and protocol is set to UBLOX. The GPS should be detected automatically, you will see it succeeded once you get a fix (use the GPS widget in the GCS, or UAVObject browser).

Alternatively, below are two ways to configure GPS for navigation.

1. Upload Preset Configuration File

The configuration file can be found. configuration file According to PUG398 "you are welcome to try this ubx 115k file to see if it works. Just remember after writing it change baud to 115k in ucenter and write it again."

Configuration procedure:

1 Download and install [U-Center](http://www.u-blox.com/en/evaluation-tools-a-software/u-center/u-center.html)

2 Obtain a USB-Serial Converter FTDI, CP2102 will both work. (cp2102 is suggested since the recent FTDI driver change has casued a lot of trouble) This one from HobbyKing should work just fine Micro SATA Cable - USB 2.0 to TTL UART 6PIN Module Serial Converter CP2102 (the advantage the HK one is it has both 3.3v and 5v. you will be able to use it on any device)

3 Connect GPS to Converter

CP2102 ---- GPS

TX ---- RX

RX ---- TX

GND ---- GND

5v/3.3v ---- 5v/3.3v

(Be cautious about the voltage. Using 5v to power 3.3v GPS could cause damage)

4 Connect U-center to USB

In U-center

Enable Receiver>Autobaudrate (this option will help you auto detecting GPS baud rate if you do not know. Usually GPS is default at 9600/38400)

Choose your CP2102 ComPort in Receiver>Port

Open a Packet Console in View>Packet Console (or F6) (this help you to quick check if there is message coming from GPS)

5 Upload Downloaded Configuration File

Open Tools>GPS Configuration..

Open the downloaded configuration file

Check "Store Configuration intoBBR/Flash(non-volatile memory) (might not work for some older Ublox those do not have non-volatile memory)

Click "File >> GPS"

Unplug and re-plug in USB, Repeat 4 and 5 one more time to make sure everything is right.

... DONE

2. Manually enable in U-Center

First, disable all messages (View->Configuration View->MSG)

Then, enable the following messages under Ublox

  • NAV-POSLLH
  • NAV-DOP
  • NAV-SOL
  • NAV-VELNED
  • NAV-TIMEUTC
  • NAV-SVINFO

And also Update rate at 100 ms. (View->Configuration View->RATE)
Mode to airborne <1g (View->Configuration View->NAV5->Dynamic Model)

Set GPS baudrate to 115200 (View->Configuration View->PRT), this will immediatly "break" communication to the GPS. Since you haven't saved the new baudrate setting to the non-volatile memory you need to change the baudarate you communicate to the GPS without resetting the GPS, and then save the new baudrate to the non-volatile memory.