I was seeing poor GPS performance - taking several minutes to detect satellites. I then spotted the Ardupilot manual page here:
Followed the instruction connecting the GPS to U-Center using FTDI adapter. GFot it connected no problem, and downloaded the 3DR configuration file as per the instructions, applying this to the M8N - which seems to switch on just the message types Pixhawk needs to function. The config applied successfully, but I noticed in U-Center that I couldn't get any satellites at all. I then read somewhere that Pixhawk sends Ublox config down to the GPS on each boot, so possibly the application of the config file is no longer a necessary step. Anyway, I linked the GPS back up to the Pixhawk and powered my hexa up in the garden for nearly 40mins. Clear blue skies but still no satellites being seen! So no GPS flying until I can get this fixed. I am actually worse off now than I was before I started!
Any advice would be awesome. Thanks in advance, Paul A
Replies
@Paul,
You have the GPS set for 38,400 baud?
Also, when I programmed my M8Q with the 3DR configuration file I did it manually and only changed those M8Q parameters that did not match the 3DR configuration file parameters.
Regards,
TCIII AVD
Darn, I just tried to edit my last message but during the edit it passed the 15minute mark so I lost all my text - a tad annoying ;o)
I managed to figure out how to apply my changes to the NVR of the Ublox (in case anyone would find this useful, in the Configuration View, after making a change in any of the sections, you click send to make it take effect, but this isn't yet written to the eeprom. So make all the changes you need, but remember to go into the 'CFG (Configuration)' section last of all and with the option 'Save current configuration' selected in the list, click the 'Send' button to do this. Learned this with the help of the Cleanflight gitub GPS doc here: https://github.com/cleanflight/cleanflight/blob/master/docs/Gps.md
Now that I have managed to save the baud rate at 38400, will the Pixhawk auto-configure the Ublox upon boot from now on?
Paul, thanks a million for posting this, I was having the same problem......and going mad......
Update - I found out how to revert settings back to default and have done this. Its changed the baud rate back to 9600, so I tried changing it back to 38400 (on the PRT tab again under configure screen), and on clicking Send, it looks like the setting has applied. I can even then change the connect baud rate in U-Center to 38400 and it connects, but then when disconnecting and reconnecting the FTDI adapter back to my laptop upon reconnect, I see it has reverted back to 9600. This is frustrating!
Hi, Just hooked it back up via FTDI and in U-Center, on the 'configure' panel, under "PRT (Ports)" baud rate is indeed set to 38400. I'm thinking there is possibly an area of config set by that 3DR config file which has upset the M8N. I know those 3RD GPS units use LEA-6H GPS modules, rather than M8N.