USB interface is an external bus standard used to standardize the connection and communication between computers and external devices. USB interface has plug and play and hot swappable functions. The USB interface can connect 127 types of peripherals, such as mice and keyboards. USB was jointly launched by Intel and other companies at the end of 1994 in 1996, and has successfully replaced serial and parallel ports, becoming a necessary interface for computers and a large number of electronic smart devices today.
The USB version has undergone years of development, and for most engineers, the main obstacles to developing USB 2.0 interface products are facing complex USB 2.0 protocols, writing USB device drivers themselves, and being familiar with microcontroller programming. This not only requires considerable VC programming experience, but also the ability to write hardware (firmware) programs for USB interfaces, so most people give up developing USB products on their own. In order to simplify complex problems, some connector manufacturers have specially designed USB 2.0 protocol conversion modules. The USB20D module can be seen as a USB2.0 protocol converter, converting the computer's USB2.0 interface into a transparent parallel bus, just like a microcontroller bus, so that the design of USB2.0 products can be completed within a few days.