Product name |
Micro OTG adapter |
Color |
White, black |
Function |
Transfer data and charging |
speed |
480Mbps |
OTG is the English abbreviation for "On The Go", which can be understood as "available upon installation". USB transfer is a master-slave structure, and all USB transfers are initiated by the Host.
A USB drive can be inserted into the development board, which serves as the USB Host.
The development board needs to communicate with the PC and act as a USB device.
The development board can serve as both a USB Host and USB Device, and can use an OTG port: it can automatically recognize its own role based on the hardware circuit and switch to USB Host or USB Deix.
OTG sockets come in various forms, commonly used including Micro USB and Type C, as follows:
1.1 Micro US
For Micro USB sockets, it has 5 pins:
When the development board is used as a USB device, it is connected to the USB on the PC. The USB interface of the PC only has VBUS, DM, DP, and GND, so the ID pin of the development board is not connected to the USB port of the PC. It is pulled up by the pull-up resistance on the board.
When using the development board as a USB host, an OTG converter needs to be connected, followed by a USB drive.
The internal circuit of the OTG converter is very simple, which is to pull the ID pin low:
1.2 Type C USB
There are two identical sets of signals in the Type C socket, and the Type C data cable can be used regardless of whether it is plugged in or out