I purchased a GS407 U-Blox5 GPS 4Hz as part of order 13206 and I am not confident is behaving according to spec. There are two behaviors which I observe. The first behavior is very consistent, it never varies. The second is new, and I have not yet tested sufficiently to isolate the conditions under which it occurs.
I should note that I also have a MediaTek MT3329 GPS 10Hz + Adapter Basic that appears to operate normally, in the same airframe, in the same locations, used at about the same time (immediately before or after the U-Blox5) and does not show either of the two behaviors.
I did not assemble the U-Blox5, it came with the DIYdrons UBlox_Basic_V10 adaptor attached and glued to the GPS.
-> The first behavior is that the U-Blox5 does not seem to report the number of satellites. I have used four different versions of APM code, including the current and last versions of APM and the current and last versions of ACQ code. When running test->gps, I see #sat as 0. When running the MediaTek, I get good numbers for this value.
Is this the normal/expected behavior for this hardware? Should I investigate further with different sketches? Please advise.
-> The second behavior, seen in the last three test flights, is that the U-Blox5 will not report consistent locations. I am in the northern virginia area, but it is alternately reporting coordinates in the middle of brazil, in central Alaska, and in the middle of the arctic ocean. This behavior persisted across three power cycles of the APM, and did not settle over an hour of observations (assumed it would sort itself out over time) After that, I finally gave up on the unit and switched over the the MediaTek to continue my test targets, and planned to ask about the # of satellite issue (and, if resolved, I will watch for this second behavior to see if it was an anomaly.
Any suggestions please? Should I investigate the hardware in more detail? Might this be a hardware problem, or do you suspect I am using it wrong in some way (bad electrical connections, bug in the code, configuration setting problem, etc?)
U-Blox5 shows the following numbers:
PRT NO 203066[obscured by antenna]
GPS BOARD_ELO_V1_080115 1107
The adaptor shows:
Tested with Arducopter 2.0.38 (and prior version, I don't remember the #), APM2.22, APM 2.211, and with APM MissionPlanner 1.0.53 (0 sat issue) and APM Mission Planner 1.0.54 (both issues)
I see in the code it looks like it is set for GPS_PROTO_AUTO (from memory) and I did not change any values.
Thank you for any suggestions. I will investigate further if you think the problem can be resolved with this hardware, I suppose I am wanting to make sure I should investigate. If, based on the symptoms, you think I have problematic hardware then I don't want to waste 80 hours poking at the software. :)