Snapdragon flight arm without GPS, TRone alternative

How do I bypass GPS lock requirement for arming ? If someone could point out the general direction, I could modify a few lines for purposes of testing.
Are there any alternatives to 3DR GPS ? It is not available in amazon or 3DR website.
Also can Trone be substituted with Maxbotix sonar? i understand Trone is ToF based and more accurate, but I am looking at basic ATLHOLD with minimal cost.


We always do our indoor Snapdragon Flight testing without a GPS lock. Did you follow the procedure for starting PX4 that is available here: ?

I suspect that there is something in either mainapp.config for px4.config that disables the requirement for a GPS lock.

I am not familiar with the Trone sensor, so I can’t help you there.

Thanks for the info. I am using the px4 codebase with build_eagle_default option. The px4.config seems to start the gps application, unlike the px4.config in ATLFlight.
I enabled the -f (fake_gps) option which seems to put out gps values. But I am still unable to ARM due to Mag calibration error. Is the onboard magnetometer functional ?
I am considering buying a ublox M8N with compass for get me to arming stage :). Any help is appreciated


The onboard mag is definitely functional. Were you able to get through the QGroundControl calibration sequence for the mag? You can also try running the mpu9250 DriverFramework unit test, just to verify that the it is reporting what appears to be valid values for each axis. The unit test code is available here:

Because the mag is onboard it is vulnerable to interference. You will get better mag performance from the uBlox M8N mag combination.