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GPS config u-blox M8N

gps
(Hosein Gh) #1

Hello all
Is there anyone know that whats is the best GPS config for middle East with u-blox M8N ?

(Dave) #2

BeiDou (China) now has more sats than US GPS. This article has some Middle East related info.

(Hosein Gh) #3

Did you ever used more than 3 sattelite at teh same time ?
Will it make gps processing problem ? Or something like late frame ?

(Dave) #4

With the M8N I think 3 sat systems is max. I’m in the US and I normally configure the GPS for GPS+GLONASS+SBAS. When I individually select BeDou or Galileo I get nothing so I assume they are not available to me. GLONASS might be 4 sats max. I’m curious what you would find be selecting each system individually and noting how many sats are seen.

(curt carroll) #5


Glonass will perform better at higher latitudes. I imagine all systems are designed to perform at the country of origin or their potential conflicts best. Latitude seems to be the major factor.

(Hosein Gh) #6

unfortunately i cant get BeiDou satellites
i tested each GPS system individually
result is :
GPS = 7
SBAS = 0
Galileo = 0
BeiDou = 0
IMES = 0
QZSS = 0
GLOSNASS = 5

(Rainer Walther) #7

Hi,

Galileo is not visible in the US: https://galileognss.eu/why-galileo-is-not-seen-in-united-states/

Activation of Galileo with parameter GPS_GNSS_MODE still does not work with current copter 3.6 and equivalent plane/rover releases.
See also: Can't set GPS_GNSS_MODE for Galileo on Ublox SAM-M8Q
I yust got some new M8N and SAM-M8Q. They all had Galileo deactivated by default. Galileo can be activated with U-Center. But SAM-M8Q forget the configuration after some days, when GPS buffer battery gets weak.

(Hosein Gh) #8

As i know Galileo is for European and I’m in middle East is it visble here ?

(Dave) #9

I’m sure there are satellites from all systems visible. I’m not sure why we can’t use them though. There are several websites that will show sats visible over a location you enter. Beirut, for a Middle East example, shows sats for all systems visible right now.

(Hosein Gh) #10

Yes Dave i agree with you
When i check websites for visible satellites i can see many of them like SBAS is visible, it seems that M8N module cant connect to them
At the same location I can’t get more than 15 satellites with M8N but i can get 23 satellites with my phone

(curt carroll) #11

https://www.gsc-europa.eu/system-service-status/constellation-information
@RainFly

I can use all constellations with an F9P. I am in the U.S. The M8N may not have the correct firmware


This is right now.

(Dave) #12

Nice. Isn’t the GPS module configured on boot from Ardupilot?

(Hosein Gh) #13

It configured by ardupilot but it seems that main problem really is firmware

(curt carroll) #14

I have made configuration changes through ucenter then left ardupilot to default to the receiver settings…

(Dave) #15

OK. You are connecting direct to the module? Passthru seemingly gives very limited capability.

(curt carroll) #16


with a M8P this is all I get. The M8P will not let me enable any thing else.
I imagine the M8N is the same.

(Dave) #17

How are you connecting U-center to the M8P? The module has a USB port?

(Hosein Gh) #18

It might be this
http://ardupilot.org/copter/docs/common-ublox-gps.html#connection-option-2-ftdi-cable

(curt carroll) #19

Yes both rover and base have usb. The rover comes with an adapter for firmware upgrades.

(Dave) #20

After some experimentation Mission Planner passthru does work at least to display the configuration and some basic metrics. But not all combinations configurable in Mission Planner are saved to the module. If I select GPS+Beidou+Glonass that’s not what U-center reports. Other combinations are saved correctly. The module I’m playing with now BTW is a Here GNSS (not a +, just generic). So the logical solution would be to configure in U-center and set “do not save” for the save config parameter (as you suggested) but I’m struggling as to how to save the configuration.