Cube, GPS, and other problems

Hi everyone

I am not new with avionics experiences but I am relatively new to the Pixhawk world and I am reading anything but you will understand that it is a very complex world

I am using a quad as an experimental platform using Herelink + PixHawk Cube 2.1

During this experimentation period I have had many crashes and not all for justified reason. For example, make 5/6 or 7 perfect flights and then the next UAV gets angry and falls on its own without the possibility of being governed.

Basically, from the logs, I noticed two rather disturbing things.

1) ESC - The first is the extreme difficulty in calibrating ESCs with Herelink. It is not like calibrating ESCs in conjunction with a normal transmitter as Herelink’s connection time exceeds the Cube initialization timeout.
I used some strategies such as using two separate power supplies (Herelink air and Cube) but also this with difficulty in calibration

In the log I always have an unbalanced part of the esc:

Test: Motor Balance = FAIL - Motor channel averages = [1780, 1758, 1559, 1644]
Average motor output = 1685
Difference between min and max motor averages = 221

In the end I adjusted the Herelink sticks and calibrated the radio then I used a Taranis and calibrated the esc with the same points (uS) … in this way it flies but I am not convinced that it is the correct procedure

2) GPS - PixHawk Cube 2.1 is equipped with a nice sheet where it indicates to connect the GPS Here + in the GPS1 port (by default the GPS has cable with Button + Led)
In this way, however, I have never seen the two LEDs light up so in fact they are not dialogue LEDs which, through the color code, identify problems or conditions (F / S, yes / no Sat, etc.)
Also every every flight, analyzing the log, I have this error message:

Test: Compass = FAIL - WARN: Large compass offset params (X: -225.93, Y: 146.53, Z: 195.01)
WARN: Large compass offset in MAG data (X: -225.00, Y: 146.00, Z: 195.00)
Large change in mag_field (43.58%)
Max mag field length (618.03)> recommended (550.00)

However, I came across a tutorial that connected Here + to CAN 1 port and modified 3 parameters that at the moment I don’t remember but that basically opened the CAN 1 port and identified the GPS.
Here, from that moment the two GPS LEDs are communicating through the color code. I have not yet flown in this configuration but I ask you if THIS IS THE RIGHT ROUTE?

Do you have any advice on this?

thanks for your interest

For the ESC calibration part, I am not sure what is happening unless I got a video.
But there is a way to calibrate them without a rc
https://ardupilot.org/copter/docs/esc-calibration.html#semi-automatic-esc-by-esc-calibration

For the GPS, the LED should go well automatically if you use it on GPS1 port in i2c mode. Check the mode selection switch.
You may have a look at this previous discussion about compass offset

Here+v2 is now support CAN mode. As long as you got what you want (GPS, compass, LED), it should be fine. Arming check will tell if you missed anything