All three types of sensor are required for the best experience in any apps that use motion tracking. None of these sensors can do the whole job of measuring device motion and rotation on their own, they all have weaknesses. (FYI this is why the Wii U Gamepad doesn't need a sensor bar, it includes a magnetometer) In effect, the magnetometer plays the same role as a Wii Sensor Bar. North is always north though (barring a polar inversion which would probably put the brakes on modern civilization) so by detecting where north is, it can tell exactly which way the phone's facing. Accelerometers and gyroscopes aren't perfectly accurate, so if you turn in place (when making a photo sphere for example), they won't be able to tell exactly how far you should be turning or when you've turned a full 360 degrees. Program the arduino to read the gyro values through I2C, trasnfer the axial values to android through hc05 bluetooth. Get a MPU6050 gyroscope, an arduino pro mini and an hc05 bluetooth module. In fact it's a 3-axis compass, meaning it can say more than just 'north is 15 degress to the right', it can say 'north is 15 degrees to the right, 8 degrees down, and your wife's cheating on you'.īesides the trivial value of knowing which way north is (maps ftw), a magnetometer is most useful because it provides an absolute reference point. Answer (1 of 4): There is indeed a roundabout. This includes everyone's favorite life-sustaining magnetic field, the one created by the earth.

This is what a gyroscope's for, it detects that type of rotation and also provides sort of a 'second opinion' on your phone's rotation because an accelerometer can be fooled by fast movement.Ī magnetometer is what it sounds like, it measures magnetic fields. In other words, if you imagine an arrow pointing in the direction of gravity, that arrow doesn't move when you rotate your phone.

An accelerometer has no idea this is happening because gravity is always pulling in the same direction.

sort of hard to explain so I'll use an example: put your phone down flat on your desk and then spin it. It detects movement in three dimensions, and since the pull of gravity is perceived as upward movement, it can tell how the phone is being held.Īn accelerometer's weakness is that it can't detect rotation if that rotation is 'flat'. The accelerometer is what's used to determine a phone's orientation.

Gyroscope android app