Odd question I know :-) but, I have the GPS blues like so many here and so far, clean power, no radio gear, isolating just the APM, ect, the only way my GPS will get lock and 9+ sats is to be powered via USB.So I would like to know if there is ANY reason why it would be a bad idea to test my APM 2.0 (internal GPS) by making a 5.0v power cable to plug into the USB port on the APM for in-flight use?P.s. I do not buy into the dirty power argument as I have a lab scope and can verify that my current flight power is cleaner than my USB port from my Laptop. Also while RFI is a real issue for GPS modules, I have gone so far as to remove the rotor head and spool up the motor on the bench without effect on the GPS while powered by USB and watching in MP.I believe the problem for MY GPS to be related to the circuitry that changes when powered via USB versus the input rail.Any foreseeable reason there could be damage trying this?
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I have a similar situation with my current APM2.5 with MediaTek GPS.
It gets a 3Dfix in the APMPlanner when plugged into the USB. When outside, the GPS gets a solid blue light, but the APM board blue and red lights (A+C) flash about 20 times, then just the red light flashes. If I arm the board, only the red light goes solid.
I have also noticed that in the Mission Planner, even when there is a 3Dfix, there are no gps values on the status page.
I'm leaning towards a similar conclusion, viz. : there is a power problem between the APM board and the GPS module.
I don't have another GPS module or APM board to test with right now, but I have checked the voltage on the APM board and the GPS board: APM is 5.0v while the GPS module only gets 4.8v
I'm ready to order my next 2 APMs, but which GPS do I go for and which version of the APM? Is 2.0 more successful with the GPS?
Stupid question: is there any way to verify that in your case the supply voltage to the GPS is correct? Since the GPS is internal it may be tricky but not impossible. I'm not familiar with the schematics of the interface board (and in any case only own an APM1) but I wonder whether that could be the problem.
Replies
I have a similar situation with my current APM2.5 with MediaTek GPS.
It gets a 3Dfix in the APMPlanner when plugged into the USB. When outside, the GPS gets a solid blue light, but the APM board blue and red lights (A+C) flash about 20 times, then just the red light flashes. If I arm the board, only the red light goes solid.
I have also noticed that in the Mission Planner, even when there is a 3Dfix, there are no gps values on the status page.
I'm leaning towards a similar conclusion, viz. : there is a power problem between the APM board and the GPS module.
I don't have another GPS module or APM board to test with right now, but I have checked the voltage on the APM board and the GPS board: APM is 5.0v while the GPS module only gets 4.8v
I'm ready to order my next 2 APMs, but which GPS do I go for and which version of the APM? Is 2.0 more successful with the GPS?
Stupid question: is there any way to verify that in your case the supply voltage to the GPS is correct? Since the GPS is internal it may be tricky but not impossible. I'm not familiar with the schematics of the interface board (and in any case only own an APM1) but I wonder whether that could be the problem.