Mavic 3 GNSS chip identified

[Raffaello_IZ0QWM]

There is an interesting note on the official DJI Forum. Someone reached out to uBlox who said they are working with DJI to fix the problem. They indicated that the December update introduced "interference" that is affecting the ability to get satellite lock and that a fix would come within the month.

It is possible that Ocusync is interfering with the Mavic 3's incoming GNSS signals.

EMI interference does not necessarily enter directly on the GPS CHIP. They can also pass through cables, antenna cables, RS-232 signal cables, test pins, motor cables.
It is possible that it was already at the limit of interference and a small change such as the voltage change of some component, the change in power, the different oscillation of some clocks, caused the EMI.

Perhaps they are doing various tests to understand which modification triggered the problem.

However, if I remember correctly, in Italy we have had satellite acquisition problems from the very beginning.

 

[mbe]

Hi,

Just wanted to ask the following question: would it be feasable to spoof the GPS TX stream on a Mavic Air 2 to get around the limitations? The idea is the following: install a small arduino (nano or Rasp. pico); the TX line from the GPS would go to a nano, and nano would also output the TX data back to the rest of the circuit.

Nano would read the incoming stream; it would apply a certain factor (2-4) to the altitude, i.e. for each additional 2-4 meters of real height above take-off point, it would add just one meter.

I wonder of there are any catches with this idea?

Possible issues:

- I assume that the GPS modules used in Mavic use standard plain ASC messages (no secure communication).
- Not sure if they may have a verification with barometric pressure, i.e. how DJI system would interpret a different altitude from GPS/pressure.
- I looked at the cable harness, it is pretty complicated to get physically; probably the best would be to open the GPS cover to get to the TX line and cut it there.
- the voltage levels probably is 3 V so a pico would be a better option.

Any thoughts about this idea?

 

[AlexKardi]

Hi all!
Can someone tell me the marking of the connectors on the GPS module for the Mavic 3? I can't find it anywhere, but I really need it. Thank you!

 

[zeusfl]

ublox?