Here3 VERY low sat count

Hi

I have been having a lot of problems with the Here3 with the sat count. Today I went to test 2 of my drones, one with Orange cube, 4.1FW, Here3. The other drone, Black Cube, 4.1FW, Here2 GPS and serial connection.

As you can see in this picture, the sat count is very different.

The one with the Here3 didn went up more than 9 sat, I have 3 drones made with the same parts, and all of them have this problem

The one with the HEre2 works great, 17Sat on the ground.

I saw a similar problem with the Here2 connected by CAN bus, may be its related with the Here3 with the CAN?

PLs help!

Thanks!

Just an update, I have connected a Here3 over CAN to the same drone it works ok, and went to give a walk with the drone.

The here 2 always get 3 or 4 more SAT here in the city.

WarmUP
imagen

After WarmUP
imagen

Max differece betwen them

May be Im missing something on the Cube configuration?

I have realized the FW on the GPS was de 1.5, so I upated to 1.7 and chechk the gnssConfig = 97 and went out again.

The results are better, but the Here3 has always 3 or 4 less Sat

This was the best case, where the Sat count 1 is the HERE2 by searial and SatCount2 is the Here3

imagen

thanks

You may try to reflash the ublox chip in Here3
https://docs.cubepilot.org/user-guides/here-3/here-3-manual#2.-here3-u-blox-chip-firmware-update

Hi Alvin, thanks for your help

I have done that and the result is the same, but i have discovered why.

Im using a MK15 remote (I prefer the HereLink, ,but because the camera I have to use a different one), and the air unit seems to generate such interference that the GPS cant get all the sats.

We had to cover the inside of the canopy with aluminium to avoid the problem, and this seems to fix it. We try do shield the GPS with cooper sheets, but doesnt work, the problem was the same.

Here are some pictures of the drone, the inside and the solution



There is any way to measure the GPS interference?

thanks

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That would require EMI measurement equipment.

You may also try to ground the aluminium instead of just having it there.

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thanks! I will