Arducopter in/on Pixhawk Mini4 not arming without GPS magnetometer on helicopter

I seem to have found that arducopter on Pixhawk Mini 4 requires the GPS external device magnetometer and will not arm with only the integrated magnetometer.
Have I fooled myself? I thought a magnetometer was a magnetometer no matter where it is located.

What is the exact message that you got.

Sorry Andras but I do not know where to look for the message.
What I do know was that until the GPS device was available the helicopter failed to arm.

Just to add to Alf’s post. The message we keep on getting is “no mag sensor 0” so I’ve tried to select it to mag sensor 1 as internal but the same message just keep on popping up and no arming possible. The problem is 90% of the pixhawk minis we recieved came with faulty GPS units where the magtometer doent work. So to get around using the internal one is a huge struggle.

What the hell is the Pixhawk Mini 4 ?
I saw Pixhawk 4 Mini, Mini Pix, Pixhawk Mini, but not aware of Pixhawk Mini 4…
Do you have a link ?

You might look at https://docs.px4.io/en/flight_controller/pixhawk4_mini.html for more information.

OK, So it is a Pixhawk 4 Mini

Copter needs a GPS, unless you explicit disable the GPS prearm check. (Assuming that you wont use any of the GPS assisted fly modes).
To override arming check have to change the ARMING_CHECKS parameter (http://ardupilot.org/copter/docs/parameters.html#arming-check-arm-checks-to-peform-bitmask) Contrary to the documentation the default value is 1 - All

i did disable the gps lock on the prearm check but the issue is with the compass. lets say i do try to fly without a gps then the internal magtometer should still work and this is my problem. any chance of flying without a magtometer senor as even the internal magtometer isnt working. we have a couple of flight controllers with the same problem.

I am using QGROUNDCONTROL on Linux to look at vehicle settings to determine why it won’t arm without a GPS but cannot find the variable ARMING_CHECK to ascertain what bits have been set.
Please tell me what I am missing. I have located a number of variables called COM_ARM_* but none that lead me to believe it is the bitmasked variable required as pointed out in the Parameter List.

You are asking on the wrong forum. COM_ARM parameters are in the PX4 firmware, this forum is for ArduPilot…

Either use Mission Planner and upload an ArduPilot firmware or check out this forum for PX4 related discussions http://discuss.px4.io/