The Study Of Multi-function Somatosensory Input System Based On MEMS Inertial Sensors

Nowadays, as the rise of gaming devices such as Kinect, Xbox, PS3, somatosensory input devices are widely used in multimedia. Compared to traditional input devices, it is easy to operate, simple to use, does not depend on the plane and many other advantages. However, the common somatosensory input devices on the market have many disadvantages, such as complex design, single function, high price and so on. In view of the MEMS inertial sensors widely used in the field of intelligent electronic systems, the micro-accelerometer chip used in computer input devices, is bound to overcome the traditional input devices depends on the plane and the operation is not comfortable shortcomings, and it is possible to bring the device to achieve multifunction. Therefore, this paper presents a multi-function somatosensory input system based on MEMS acceleration transducer.The system gets palm's static and dynamic acceleration parameters on each axial space with the help of a single accelerometer. It converts acceleration signals into the angle of palm, angular velocity, displacement and so on. And the design uses the TI CC2540 SOC chip based on Bluetooth Low Energy 4.0 to get wireless communication between the system and computer. At the same time, according to user-selected functional mode, it calls the corresponding algorithms for gesturing analysis and processing. Finally, it realizes the mouse, wheels, joystick and other common computer peripherals' input functions.On the hardware design, the system consists of MMA7361 acceleration sensing circuit, CC2540 Bluetooth control circuit, key circuit and power supply etc. Acceleration signal sampling, conversion, encoding and transmitting the series of processing completed by programming on the CC2540 chip. So the hardware circuit just needs a small part of the peripheral devices, thus reducing the circuit noise and hardware costs. In addition, the paper presents the hardware features of the software design concept, based on the NI Lab VIEW graphical platform, realizes the control algorithm functionality of mouse, wheel, joystick and some other different peripherals' functions. Finally, the design developed an interactive feature of somatosensory input software program, thereby widening the prospect of application software.The tests show that the system can successfully reflect user intentions. And the report rates are up to 125 Hz. It is stable, precision and easy to operate, particularly suitable for meetings, classrooms, halls, and other occasions.