Input.compass horizontal shaking

Hi all! I'm trying to build some sort of compass app (android). Simply via a camera oriented to a canvas(with webcamtexture) and the sprites which oriented around my camera( with a degree marks). Unity 5.3.1f The image to understand:

http://i68.tinypic.com/ivwn10.jpg

When I turn my phone in horizontal projection those degree marks are not turning smoothly. They are quite shaky. The video to understand:

http://sendvid.com/2ygl2vqm

Any ideas why it's so shaky? And how to fix that?

The code:

 using UnityEngine;
 using System.Collections;
 
 public class QM_Compass : MonoBehaviour {
 
 private Transform myTransform;
 public int facingDir;
 public int degreeOffset;
 public float test_float;
 public Transform scrollBar;
 
     void Awake()
     {
         Input.compass.enabled = true;
         Input.location.Start();
 
     }
 
     void Start ()
     {
         myTransform = transform;
     }
         void Update () {
         test_float = Input.compass.trueHeading;
         if (test_float > 360) test_float = test_float % 360;
         transform.eulerAngles = new Vector3(0, test_float, 0);
         degreeOffset = facingDir = (int)test_float;
     }
 }