Based On μC/OS-Ⅱ Mobile Terminal Extensions Design And Implementation

Mobile Extension terminals expansion the function of phone without changing hardware, and it is a Auxiliary equipment using in some SPecial applications. Expansion the functions such as infrared communications, axis orientation and acceleration, temperature, barometer's detection capabilities. Mobile Extension terminals communications with phone by USB, it could plug and play.The design of Mobile Extension terminals by PIC24FJ256GB106 microcontroller andμC/OS-II operating system, it could be acquisition and processing by each sensing module, as well as the terminal with phone by USB.1) this paper analyzes the characteristics of the microcontroller PIC24FJ256GB106.redefined and programming data types and related functions base on the hardware. Achieved theμC/OS-Ⅱoperating system migration.And the system could improve the overall stability and real-time event processing.2) Achieved USB communication base on USB serial interface engine in PIC24FJ256GB106.USB host service task program contains system level, device driver layer and application layer, system level hardware control through USB, USB realized equipment, detection, enumeration, configuration and management; USB device driver layer in the USB system, based on the level of the USB CDC class bulk transmission, application layer software to "read" and "write" interface function; practical application layer scheduling-related functions are realized according to the actual needs of mobile phones and mobile phone communication between the terminal expansion.3) data acquisition, receive the data collected for each module and, based on different data sources to add header and parity bit data to form a data packet; resolve the command packer get from phone, he command will be parsed passed to the appropriate module, and more actual answer secret order to restore the package.4) inter-task communication and synchronization, The USB hosting services task and data acquisition task are independent and interrelated. When the data acquisition tasks waiting to send data packets should to notice the USB when USB idle——the semaphore; complete collection of sensor modules or USB can be transmitted again should timely notification the data acquisitions task——message queue.Finally, the system functional testing and performance analysis, while the work on the host system applications are summarized and proSPects, and the forward need of continue research.