So here's the issue:
My APM2.0 always has the 3DFix light go solid within a couple minutes, but quite frequently Mission Planner will display "No GPS" (and of course hdop:0 and sats:0) when connected via 3DR radios. I can get the GPS to register by disconnecting Mission Planner, pressing the reset button on the APM2, and then reconnecting Mission Planner. The GPS will keep its 3D Fix during the AMP2 reset. Sometimes I need to do this more than once before "No GPS" will turn into "No Fix" or "3D Fix" on Mission Planner. Everything seems to work fine when connected via USB instead of radio. All other sensors/telemetry work fine. I am using Mission Planner 1.1.85 and ArduPlane 2.34, which are the current versions.
Does anyone know why Mission Planner fails to detect/read the GPS on my APM2.0?
Are you running it off another battery? Or directly from the main battery?
I'm running everything from a single 7.2v battery. Since I'm using a joystick, I don't have a receiver. The ESC (w/ 6v BEC) powers all the servos through the APM2 output rail. The lone BEC (5v) powers the APM2 through the input rail.
I agree Cody, having all the same problems as described here, I solved mine by using a LC filter on the supply to the input rail. So simple yet weeks of frustration.
I guess my problem is a bit different: get sats but no 3dfix no matter how long I wait.
Tried using my CC BEC on the output rail with no difference. Still stumped :( Think it may just be a hardware issue
George: Cool idea. I've seen a lot of BECs come with chokes on the output lead.
Johnathan: Does it get a fix when is connected to just the USB? Try removing the jumper from JP1 and powering the board through the input rail with your BEC. Also, if you have other electronics on-board, try letting the GPS get a fix before you turn everything else on.
Nope, nothing gets me a fix any more. The strange thing is that I used to have no issue getting a fix. Hence, why I think that the GPS is damaged somehow. Just don't know how, especially since it's still see Sats.
My receiver is powered directly via the lipo. So, nothing is drawing it's power from the APM currenlty
Maybe if you could describe your setup and the steps you've taken to troubleshoot, it could give some idea of what's wrong. Right now it sounds like bad power or some other interference.
You can see my discussion about this above. Basically, I get a consistent blinking 3dfix, but never solid blue. When connected via USB, same story but the MP reads sats and an hdop = 9999.
When running off of battery I have tried using a BEC at 5.1v to power the APM seperately. No luck
As I mentioned, for about 4 months, I never had this problem. No major changes to hardware that I can think of to cause this problem either.
"I was getting 5-7 sats consistently, but there was no lock. 9999hdp as well"
"I really am out of ideas. 1.5+ hrs of 6-7 sats with no 3Dfix."
It could be your environment. At my office I get 10-11 satellites, but the location dances wildly up to 100m. My best guess is that all the nearby sheet metal covered buildings are playing havoc on the GPS signal. At my rural testing grounds it's another story; I get a fix good enough to track a 1m width walking path. Try taking your bare APM2 to a different location and see if you get a lock then.
Hmm.. could be, but then again, I would get lock no problem in the same environment prior to this issue. I will try in an open area when I get a chance. Thanks for the tips
Got a similar problem MTK does what it wants to do, and have tried all power configurations, with varying degrees of failure. (It will lock up sometimes.....sometimes!)
With the APM2 built in MTK , which is giving me nothing but problems, so want to shift the GPS to another port at 38400, having trouble getting the APM to switch GPS onto another UART to make the nightmare MTK redundant and use a known good GPS...(ublox)
It would be helpful if any of the community has/is/or trying to do exactly this, some input would be really great!
(complete noob on APM2 (many year exp on AP/APM1), only just got it up and running however, i have had problem after problem with the MTK units, either on their own, or in other applications over the last few years, IMHO they are too easy to blank/upset/annoy...never really experienced belligerence and or petulance in an inanimate object before : ) Perhaps dinner and flowers might be required to get them to put out for us!? )
Personally, i have no issue if a unit is screwey, but it must be realiably screwey. so you can create a work-around...not what seams to be a completely random set of behaviours, based upon, whether you have black or grey underware on, which type of car is parked outside no.30 on a wednesday morning, and if planet X is having a solar eclipse..
MTK units have given me issues on AP (all 6 we have flying) APM1 (2 off) Remzibi OSD (3 off) drops out all the time, loses home....
I am wondering if the unit itself, has enviromental requirements, that MUST be met, but only work fro a portion of this community, location depending.
Either way i have 8 of these suckers....and not one, behaves in a predictable fashion, in relation to itself and the others.
Ublox.....every time....on the nail! No questions...no mucking about....
Another issue here in the UK is that there are no WAAS or similar so we cant grab extra data from other sources..
Anyway looking forward to anyones thoughts on tthis issue.
There's guide floating around somewhere on this site that shows you how to disable the onboard MTK GPS. I *think* you solder-jumper pins 2 and 3 on the GPS to disable it, then just connect the external GPS and you're ready to go.