An IMU (Inertial Measurement Unit) is a device which contains various sensors such as accelerometer, gyroscope, magnetometer etc. An accelerometer can measure vibrations, linear acceleration, force experienced etc by a body. Gyroscope measures angular velocity of an object. A magnetometer can detect magnetic field in the surrounding there by providing orientation of an object.

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MPU-6050 an IMU which has a 3-axis accelerometer & a 3-axis gyroscope. It can be used to obtain the orientation of an object along the three axes.