Have you ever drunk like a pool of mud? How about the feeling? When you’re trying to program your spider robot/helicopter or 2 wheels balancing robot, if you can’t control your robot posture, balance, orientation or movement properly like you want? Do you want your robot running like that? Of course not! Generally speaking, we need to use an IMU module to solve these kinds of problems. An inertial measurement unit, or IMU, is an electronic device that measures and reports on a craft’s or vehicle's velocity, orientation, and gravitational forces, using a combination of accelerometers and gyroscopes, sometimes also magnetometers. IMU modules are widely used for vehicle-installed inertial guidance systems, reporting inertial measurements to a pilot or balancing control, which is at the heart used in the Segway. So how can we select a suitable IMU module for your projects or hobbies!? We’ll recommend three powerful mainstream IMU modules and compare their specification for you!