Research & Implementation Of The Key Technique For A Handheld Information Terminal Based On Two Kinds Of Wireless Transmision

Handheld terminal is an important application direction in embedded fields, especially in detecting, communicating and information capturing fields. Multimedia information collection and real-time transmission for the field can be a full preparation for next step, and plays an important role in daily life. This design has built a general dual mode wireless multimedia information collection platform, which implements the key technique of image collection, audio collection, information assistance management and dual mode wireless information transmissionIn order to illustrate this design, the paper takes the handheld device which urban management persons hold for an example. Aiming at the problem of incomplete information collection, non-real-time transmission in the urban enforcement and the lack of supervision and feedback in the process of enforcement, this paper proposes a technique solution about a handheld urban supervision information terminal.The design is built in C/S mode. The client is based on the embedded PXA270 platform, while the server is the supervision center. The client captures the image and audio information in the process of enforcement. It also makes use of information assistant management module to record events. The supervision center as the server receives and shows the information transmitted from the client. Then it feeds back the result of event handled.First, the embedded development enviroment is built based on the PXA270. Then we design and implement the image capture module, audio capture module, information assistant management module, the operation GUI module and the Chinese language input and display module on the PXA270 client while the server consists of the remote supervision module and file show module. For the realtime transmission of the acquired information, the two ways of GPRS and WLAN are used to transmit wirelessly between the client and the server. The design has achieved the expected aim with embedded Linux thchnologie by taking technically demonstration and implementation to solve the problem of incomplete information collection, non-real-time transmission in the urban enforcement and the lack of supervision and feedback in the process of enforcement. Although this design is about the design and implementation of portable urban management supervision information terminal, the main technologies and approaches of research can also be applied to portable terminal devices in other fields.