U-Blox troubleshooting

I am working with a Ardupilot Mega using a U-Blox GPS but I am not able to get a lock and I need some advice on how to troubleshoot this. I have read that the first sat lock can take as much as 15 minutes with this GPS so I have left it outside for a while. My deck has a clear view of the southern sky so I dont think the outdoor conditions are the issue. The APM continues to flash the ABC lights which indicate no lock. I assumed the issue was a lost config so I downloaded the U-Center 6.01 software and had no trouble connecting to the GPS at 38400 but I cant get a lock while connected to this either. I am very new to this so I am sure its something simple but I cant think of anything else to try. Any advice would be greatly appreciated.



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  • Fred

    You mostly only get a lock if you are under free sky.
    Did you connect it with a correct cable that is branched with the arduino?
    Did you configure APM_config.h APM_GPS_UBLOX?
    In GCS-Test mode you should get a gps lock.


    I am not quite sure, but the functions in various modes run correctly only with a gps lock.
  • 3D Robotics
    If you're outside and connected to Ucenter and it's not showing a lock after 20 minutes despite showing other data, then you may indeed have a bad unit.
  • Developer
    So two things to try:

    1: if you have good comms with Ucenter then just leave outside longer and assume nothing is fried
    2: make sure the message that sends the lock status is turned on also check to see if you are getting good readings. You can have a lock and good readings but if the lock message isn't part of the package then all you will get is data you just wont know if it is good or not.

    Also, I found out the hardway before Ublox were cheap, that if you hook them up to the wrong voltage they will fry somehow in crazy way. They still work and send messages but never get a lock. Kinda stupid but true!

    Good luck
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