Find which sensor errors you had

[LbinNC]

Hi all

i took a quick flight by one of our local water falls, still getting my confidence up so I didn’t venture far from the banks.

MM was flying fine but I saw a few sensor errors pop up and quickly disappear. Not knowing what they were I decided not to risk the AC and brought her back.

I looked at the flight on airdata and I didn’t see anything except maybe it was a little low on Sats... I got the cleared for takeoff but it did fluctuate between 6-9 during the flight as I was in a forest. I am sure the display showed 10 when I took off but didn’t see that in the HD playback.

would be good to know what is a critical sensor error as opposed to a warning

Thanks
LB

 

[old man mavic]

Hi all

i took a quick flight by one of our local water falls, still getting my confidence up so I didn’t venture far from the banks.

MM was flying fine but I saw a few sensor errors pop up and quickly disappear. Not knowing what they were I decided not to risk the AC and brought her back.

I looked at the flight on airdata and I didn’t see anything except maybe it was a little low on Sats... I got the cleared for takeoff but it did fluctuate between 6-9 during the flight as I was in a forest. I am sure the display showed 10 when I took off but didn’t see that in the HD playback.

would be good to know what is a critical sensor error as opposed to a warning

Thanks
LB

the no of sats was on the low side you were getting messages because the sats were being blocked by trees and the hills around the location

 

[LbinNC]

Thanks OMM. I knew the sats would be impacted but
would be good if those were yellow errors and not red !

Not knowing what sensor was throwing the error mid-flight I assumed the worst and landed

 

[old man mavic]

Thanks OMM. I knew the sats would be impacted but
would be good if those were yellow errors and not red !

Not knowing what sensor was throwing the error mid-flight I assumed the worst and landed

there are no sensors on the MM apart from the ones underneath the warnings were in red because you were flying without enough sats locked at times and they are meant to make you take notice which you did and you were probably to high for the downward sensors to detect the ground ,or water

 

[LbinNC]

Didn’t know if it was IMU or ECS errors.... appreciate the info.

I guess sport mode is the least assisted if it loses all positioning sats. My 3DR had a manual mode where it as all pilot if the crap hit the fan

 

[DanMan32]

I'm not sure what those brief, generic "sensor error" were about either. Based on context of when they popped up, usually still on the ground, I thought it had to do with the downward sensors being too dark. There's almost no clearance between AC bottom and ground.

My next thought was one of the IMU sensors.

 

[LbinNC]

Flight link if interested...
if I had to guess I was Between 20 & 30 ft high when I saw the errors

 

[douglas_in_philly]

I guess this may have already been established, but in your flight data, under "Sensors -> GPS" it shows all red, indicating too few satellites.

 

[LbinNC]

Douglas thanks that is what I was assuming caused the alert after looking at the logs, 8 was min to take off.

Flashing red sensor error indicated to me a major issue (I guess loosing sats could be considered that) but I would have thought maybe yellow to indicate an no critical issue.

I thought it might have been an IMU or ECS issue in flight, hence the landing. I knew it was a sat drop I might of continued and picked up more as I moved into the open.

To me RED means get down ?

 

[DanMan32]

Reduced GPS sats shouldn't report as sensor error. There's nothing wrong with the GPS receiver, just less to receive.

 

[sar104]

Flight link if interested...
if I had to guess I was Between 20 & 30 ft high when I saw the errors

The problem with the Mini logs is that the app tip, warning and serious warning fields are not populated with the usual error messages. You can still figure them out by looking at the error-specific data fields, but the websites such as AirData are not doing that. In this case all the errors were in the category OSD_nonGPSCause, and were all GpsPositionNonMatch.



That was due to insufficient GNSS satellites locked:

 

[sar104]

Reduced GPS sats shouldn't report as sensor error. There's nothing wrong with the GPS receiver, just less to receive.

Actually it does if GNSS position solution diverges from the IMU sensor fusion result.

 

[LbinNC]

Thank you for the analysis and link to the guide. I guess an IMU calibration is in order ?

 

[sar104]

Thank you for the analysis and link to the guide. I guess an IMU calibration is in order ?

I don't think there is anything wrong with the IMU - you were just marginal on satellites.