The embedded broadcasting system based on CAN bus

The purpose of the study is to design an embedded broadcasting system based on the CAN (Control Area Network) bus for a computer-assisted learning application. In the system, the several embedded USB switching module (EUSM) are combined and linked. The EUSM consists of a USB host chip and a USB slave chip, and the USB device driver are embedded to extend the usability. The module excels in signal switching without re-enumerating USB keyboard and mouse, and it is able to evaluate the effectiveness of simultaneous signal switches in computer-assisted learning application. In addition, the EUSM can be realized in three modes of operation: Host Device Mode, Pass Mode, and Slave Device Mode. The integration of multiple EUSMs can be realized by a computer-assisted learning application with optimal performance, ranging from one PC (master or instructor PC) to 229 PCs (slave or student PCs), through CAN bus network using extended frame format. The CAN provides a safest communication channel to exchange up to 8 bytes per frame between several network nodes or EUSM. The embedded broadcasting system cooperates easily with any other classroom broadcasting systems to provide the finest instruction with USB keyboard and USB mouse in the interactive learning environment.