Research Of Data Transmission Equipment Based On USB OTG Technology

USB devices are everywhere nowadays, such as flash drives and USB printers. But it is known to all that computer is necessary in USB devices based data transmissions. This is because USB 2.0 transmission protocol defines that USB mobile terminals can only be used as peripheral devices, so it can only communicate with the host through USB hubs. To solve this problem, this project intends to design an intermediate transit device which is able to transmit data without PC. As the name suggests, an intermediate transit device enables two USB devices to transmit data, without using computer.The main processor of this project is ARM, including peripheral functional circuit such as touch pad module, SD/MMC module and standard USB module, ISP 1362 USB OTG controlling chip as its another core. This project is designed to enable touching pad devices to transmit data. USB OTG devices are compatible with USB OTG protocol. Besides USB 2.0, it also adds HNP(Host Negotiation Protocol) and SRP(Session Request Protocol). Therefore USB devices are no longer peripheral devices any more, but can also transmit data with other mobile terminals as hosts.In order to distinct with other OTG devices and improve its serviceability, this project additionaly puts forward the concept that compress and depress programs be implanted in the operating system in USB OTG devices. By comparison and analysis, we consider that it could transmit data with Windows systems and the embeded operating system should be limited into certain space. So this project uses zip file compress and depress program. Through embeded operating system, users are able to choose whether they need to compress files while using this device. This function meets the needs of transmitting data through storage devices and media player devices, and multi files can be compressed in the same time.