# Unable to calibrate compass on VOXL CAM w/ Flight Controller

Source: https://forum.modalai.com/topic/699/unable-to-calibrate-compass-on-voxl-cam-w-flight-controller
Category: Flight Core and Legacy VOXL (https://forum.modalai.com/category/9/flight-core-and-legacy-voxl)
Tags: voxl-cam
Posted: 2022-02-02 13:01:47 UTC by marian
Replies: 3 · Views: 1022

## marian · 2022-02-02 13:01:47 UTC

Hi, I"m just finished to mount the voxl cam w/ fligth controller on my frame and did all the connections. 

It ask me to setup the frame which is a generic X, and ask now to calibrate the sensors. All is fine for the Gyro and accelerometer, but I tried several times to calibrate the compass and didn't work.  I let the rotation angle to NONE. 

Do I should setup a Rotation angle before to calibrate the compass?

Thanks for your answer!

## Reply by Chad Sweet (ModalAI staff) · 2022-02-02 17:16:49 UTC

There is no built-in magnetometer. Have you connected a supported GPS/Mag unit to J10? See details here: https://docs.modalai.com/flight-core-datasheets-connectors/#j10---external-gps--magnetometer-connector

## Reply by marian · 2022-02-03 16:11:43 UTC

Thanks for your answer. That's normal then, because I didn't attach a gps to the board. My intention is to use it on indoor.

## Reply by marian · 2022-02-04 15:57:04 UTC (in reply to Chad Sweet)

@Chad-Sweet Hi Chad, I go further and for the accelerometer calibration I have another issue. 
 
1) With Rotation None, the QGC see my aircraft on left side instead of level position, and so on. 
When I test to arm and take off, it see the vehicle as turn on right side and have failsafe issue.

2) If I put Rotation = Roll 270 is much better, and I can arm and takeoff (just simulate for now).
Still, I have two positions that are not right, aka it show the vehicle on:
- left side instead of noise up
- right side instead of noise down

I would really appreciate your help to indicate me the right value for the Rotation to well calibrate this sensor.

Thank you!