USB interface definition and USB interface outline drawing - Database & Sql Blog Articles

USB is a commonly used pc interface, he only has 4 lines, two power supply two signals, as shown below. So the signal is serial transmission, the usb interface is also called serial port, the speed of usb2.0 can reach 480Mbps . Can meet a variety of industrial and civilian needs

The four lines of the usb interface are generally allocated as follows. It is necessary to note that the positive and negative poles must not be reversed, otherwise the USB device or the south bridge chip of the computer will be burned:
Black line: gnd
Red line: vcc
Green line: data+
White line: data-

USB pin definition

Pin Name Description 1VCC+5 VDC2D-Data -3D+Data +4GNDGround

In general:
Red (Vcc), white (D-), green (D+), black (GND)

Mini usb pin definition

Pin function color note 1V BUS red power +5V2DATA-white data-3DATA+green data+4IDA type: connected to the ground
Type B: not grounded (empty) 5GND black ground

The ID pin is used in the OTG function. Because the Mini-USB interface is divided into Mini-A, B and AB interfaces.
If your system is only used as a slave, then use the B interface.
The system controller will judge the level of the ID pin to determine what kind of device is inserted. If it is high level, the B connector is inserted. At this time, the system will be in master mode.
If the ID is low, then the A interface is inserted, and then the system uses the HNP session protocol to decide which is the master and which is the slave.

From left to right: miniUSB male port (type A plug), miniUSB male port (type B plug), USB male port (type B), USB female port (type A socket), USB male port (type A plug)