Data Acquisition And Wi-Fi Transmissions In The Image Meter Reading System

With the development of video processing technology and processor performance, videomonitoring system is becoming more and more intelligent and networked. In this paper, thecombination of embedded technology, video technology and network technology realized agraphical meter reading system based on ADSP-BF532platform.The graphical meter reading system was built by using a low-cost Blackfin532as a coreprocessor, has the advantages of low cost, low power consumption and small size. Externalimage obtained from two common types source of CMOS and CCD surveillance video, theformer output the ITU-R BT.601digital video streams, and the second one’s output should beconverted to ITU-R BT.656standard by video decoder MAX9526. The DSP can receiveimages and video data that reached processor at a ideal frame rate in real time. Whilereceiving video data in real time, the image and video can be processed and transported viaWi-Fi on DSP platform. JPEG and MPEG compression was used on single image and motionvideo stream. The experiments showed that, image and video stream could be compressed,stored and transported in real time during receiving a real-time video signal.BF532could read and write FAT32format file on high-capacity SD card through SPI port,and store compressed video data on SD card in real time. Since Wi-Fi module was used totransport data, in order to meet the complex network protocols, uClinux was chosen asembedded operating system.In this paper, read and write operations of the high-capacity serial Flash was improved,that is the precondition of porting uClinux. Compiled a configured u-boot as a kernel bootprogram, cut and optimized the uClinux kernel. The uClinux was ported on BF532processorafter cross-compiled on Linux platform, providing complete software, file managementsystem and network communications. The PPI, Marvell8686and DM9000driver wastransplanted to uClinux system according to the characteristic of video formats and networkprotocol. The upper layer program was coded, that achieved real-time image acquisition andprocessing, completed the data transmission between the platform and the host through Wi-Fi,reached the requirements of meter reading system.