# No valid data from Compass 0

Source: https://forum.modalai.com/topic/2601/no-valid-data-from-compass-0
Category: General Questions (https://forum.modalai.com/category/2/general-questions)
Posted: 2023-08-29 01:07:17 UTC by SMRazaRizvi
Replies: 3 · Views: 688

## SMRazaRizvi · 2023-08-29 01:07:17 UTC

I recently flashed my Sentinel drone and calibrated the Compass, Gyro, and Accelerometer.

All the Sensory data is Green, as can be seen below

![fffef22b-4d44-4449-a688-c82c121da4f2-image.png](https://forum.modalai.com/assets/uploads/files/1693271144230-fffef22b-4d44-4449-a688-c82c121da4f2-image.png) 
However, after the first arming, I'm continuously receiving `Preflight Fail: No valid data from Compass 0` , not allowing me to arm and fly again, as can be seen in the QGC Logs below.

![a1b63573-45d0-4dfb-93e5-48bcaf6bc2bc-image.png](https://forum.modalai.com/assets/uploads/files/1693271178119-a1b63573-45d0-4dfb-93e5-48bcaf6bc2bc-image.png) 

Please help.

## Reply by Eric Katzfey (ModalAI staff) · 2023-08-29 14:43:23 UTC

@SMRazaRizvi Are you saying that you can arm and fly just fine but after landing you cannot attempt a second flight due to this error appearing? Does this happen every time you fly?

## Reply by SMRazaRizvi · 2023-09-01 13:49:10 UTC (in reply to Eric Katzfey)

@Eric-Katzfey 

I figured that was because I was not getting the GPS signals inside the lab.

I don't get the compass error if I try to fly outside.

## Reply by Eric Katzfey (ModalAI staff) · 2023-09-01 15:15:09 UTC (in reply to SMRazaRizvi)

@SMRazaRizvi A compass (magnetometer) and a GPS receiver are two completely separate sensors. GPS reception won't affect the compass.