With regards to a M8N GPS connected to a APM 2.8, is it normal for it to be wildly moving around while the Quad is stationary on the ground? On Mission planner it shows the Quad moving all over the place, around +- 20 meters to where it is situated. The sat count is around 7 to 8 and the HDOP value is 2.5. It there anyway that the accuracy of the GPS can be improved. Also, when i switch into the land mode after a flight, the quad starts descending, but then drifts suddenly to the right. Luckily it hasn't crashed yet as i have taken manual control of the craft before it hits the ground. I don't really want to try the return to launch mode if the GPS is showing the Quad in the wrong place, and it cannot land itself. Any suggestions to fix these issues?
You need to be a member of diydrones to add comments!
Replies
pls see the image craig
UBX image.png
Without knowing if you're running plane or copter I really can't say as they are a lot different on plane or copter and worse when you go back to APM copter 3.1.5 is the latest and last version that will install on APM boards and APM Copter 3.1.5 doesn't support dual GPS. 3.2 didn't support it, it only logged it. Plane is different though but I have 0 experience with plane.
did you mean this link?
http://diydrones.com/forum/topics/m8n-gps-apm-2-8-accuracy-and-land...
Sriram said:
thank you craig..... can u tell me about dataflash UBX message??
Most consumer level GPS units are pretty rubbish but 4 to 7 is pretty iffy. They never will read exactly the same. Differences in the antennas, heights, EMF, and a ton of other things effect reception and with these little ceramic antennas, active or inactive, make these little 20 dollar units operate all over the spectrum from "spot on" to "where the hell am I" as far as performance goes. And using 2 just compounds the problem. I stopped using 2 GPS's a long time ago.
Most GPS have a +/- of 2.5 meters accuracy anyway
Now with the introduction of RTK at an affordable level has changed a lot of that.
http://docs.swiftnav.com/wiki/Integrating_Piksi_with_the_Pixhawk_pl...
http://diydrones.com/profiles/blogs/affordable-new-rtk-gps-designed...
Looking for high precision GPS then that is the way to go.
Hello
I have dual neo m8n gps setup in pixhawk. the issue is both gps latitude and longitude shows different values. they differ by about 4 to 7meters. why this is happening? Is there anything can be done to get both reading same?
In dataflash log I have UBX1(instance,noiseperMS,jamind,agccnt,apower), UB2(magI,magQ,ofsI,ofsQ), UBX3(hAcc,vAcc,sAcc)
what are these values? how to use these values?
I have a M8N from HK here in NZ and usually get around 16 sats pretty quick and think I saw 20 the other day. Had a LEA-6 before but used to take 15min to find 6-8 sats.
There is the module above, it doesn't look to be the one that you described. The gps is positioned above the controller by about 15 cm. It is away from all the ESC's but reasonably close to the telemetry transmitter
Looks like you may need to build a backplane. I normally cut a square bit of aluminum [about 1/2 inch larger than the GPS module] then over that I put some copper and it always helps my GPS modules when there is a need. I use copper sheet foil here
Attached is what I mean. Sorry bout the crappy pic but you should get the idea.
Thanks for that. Will look into making one. Could my geographical location be playing a part in the number of satellites i pick up as I i am down in New Zealand?
-
1
-
2
of 2 Next