Low cost position sensor and mobility device using the same

A low cost position sensor and a mobility device using the same are provided. The low cost position sensor comprises a rollable object, a container and a control circuit. The rollable object comprises a specific material. The container has a non-planar inner bottom portion. At least one sensor for detecting coordinates is disposed inside the container. The rollable object is disposed in the container. The sensor can detect the specific material. The control circuit is coupled to the sensor. The sensor detects the specific material to determine a coordinate position of the rollable object, and sends the coordinate position of the rollable object back to the control circuit. The control circuit determines a tilt angle of the container according to the coordinate position of the rollable object.