Problem with GPS

ArduCopter Copter 3.5
1

Hi,
long time ago I used to have about 15 satelites on my copter with u-blox m8n. Now I have new copter and new m8n and have outside about 7-8 stats. Inside about 7. I read about problem with interference from telemetry module so I disconcted TM but no difference.

I contected gps to U-center and have about 4 green and 3 blue sats… I pres some buttons in u-cetner, I guess it was hotstart, warmstart and loose all satelites. They didnt come back…

Back in MP gps connected in pixhawk and I dont have any satelites. Also set gps autoconfig in MP to 1 but no difference.
Please help…

2

The satellite constellations above you change all the time.Please retest again at a latter time.
But yes, the problem might be interference, try to disable all transmitting devices near the GPS receiver, including your cell phone.

3

I found out that baudrate on gps now connect at 11520 (previsouly 38400) - tested on u-center I dont know why it changed, maybe beacuse i presse cold start and it erased the settings?

I set serail 3 baudrate to 115 in MP but still no sats…

4

Ok found a solution…
u-center:
reset settins to factory default (there is buton with gearbox and red arrow)
Now satelites should show up (check correct baudrate)
PRT - set baudrate to 115200, protocol out si now UBX +NMEA, pixhawks use only UBX, but once you switch to UBX U-center doenst shows any satelites, thats ok, set to UBX

  • protocol in: UBX+NMEA
    RATE - period 200ms
    CFG - save current config->Send

MP:
serial port 3 baudrate: 115
GPS auto config: 1
GPS GNSS mode: 0 or 67 (had 3 but it didnt work very well)
GPS_save_CFG: 0
GPS type: 2

5

ArduPilot flight settings turn off the reporting of what satellites are tracked over the ublox protocol. If you let ArduPilot save the GPS configuration this is why it couldn’t tell you what satellites were being tracked. (Should still tell you the total number its using however).

6

Also worth noting that GPS_GNSS_MODE 3 means you only track GPS and SBAS satellites, which means you are’t tracking Glonass anymore and reduces the available number of satellites.