GPS glitch definitions

ArduCopter Copter 3.1
1

3DR 2013 quad, 3.1 firmware.
880 motors and 11 inch props. Flying at 6,300 ft AGL. 10 MPH gusty wind from the south.

Below is a log of a test flight to see how stable the quad is in Loiter. Took off in Stab and rose to about 20 feet or so, switched to Loiter. It stayed stable but working too hard to stay in one place for a few seconds then took off up and away - wind blowing it north - till I caught it in Stab, brought it back and landed.
The APM was updated with the latest firmware yesterday and the ROM erased. We did the full set of calibrations of the accels, compass, etc. Manually entered the compass offset and calibrated the I and V sensors. Everything PID wise is default.

In the log from the APM there appear to be two GPS glitch messages. Plotting the lat and lon looks OK but the messages show up in those plots and the (very nice!) feature in MP to auto plot GPS errors. Problem is I don’t know what the data values in the glitch messages tell me so I don’t know where to look for the problem.

It may be interference. I was flying about 50’ from a dish that is the 5.7 GHz link to my wireless internet. But I need to know the nature of the glitch to dig into this further. Might also be the cable - it has been through several crashes. I’m also somewhat suspicious of the voltage regulator in the APM. Looking at the 5V servo power output there is about a -.4V pulse on that output. Seems like a lot for what should be a regulated 5V out.

Any help appreciated.

2

6300ft AGL? Really, above ground level? Or 6300ft MSL - above sea level?

Sent from my Ainol Novo 7 Fire using Tapatalk

3

Sorry, MSL. Near Denver, Colorado.

The question is, there is data in the GPS glitch messages in the log. Where can I find the definitions of that data? I’m hoping that will tell me if the signal was lost (interference) or the connection was lost (cable or bad GPS).

4

[quote=“jjwhite”]Sorry, MSL. Near Denver, Colorado.

The question is, there is data in the GPS glitch messages in the log. Where can I find the definitions of that data? I’m hoping that will tell me if the signal was lost (interference) or the connection was lost (cable or bad GPS).[/quote]
If connection to the GPS were lost, the GPS messages in the log would stop. A GPS glitch is interference.

5

Thanks. That’s what I needed to know. I will avoid flying into the beam width of that antenna.