1, USB data cable is used to connect the phone and the computer, it can access the phone through the computer photos, music and other data. At the same time, because the mobile phone has its own memory or expansion card, so in a sense, the mobile phone is another kind of U disk. Of course, it is also an essential connection bridge for charging mobile phones, tablets, MP4 and other digital devices.
2, OTG data cable, your mobile phone does not need to go through the PC or notebook, you can directly through the OTG data cable and USB USB devices such as USB disk, mouse, keyboard connection, that is to say, the mobile phone can directly connect to the USB disk to find information, connect to the mouse to play games, connect to the keyboard fast typing, connect to the camera to browse pictures, that is, shoot and pass. In other words, the OTG line saves the step that each device must go through the computer to communicate information, which not only expands the function of the mobile phone, but also makes us more convenient to connect with the Internet, and is more suitable for the development of this mobile Internet era. Tablets and other OTG-enabled digital devices are also available.
3, the difference between OTG cable and ordinary USB cable is also that: when the USB data cable is connected to the computer, the external device is powered by the computer, and when the OTG data cable is connected to the device such as the U disk, the main object such as the mobile phone must supply power to the peripheral devices such as the U disk.
4, so how does the mobile phone identify the USB data cable and OTG data cable? After disassembling the two wires, you will find that the 4pin of the USB data cable is suspended, the 4pin of the OTG data cable is short connected to the ground, and the mobile phone chip should determine whether the OTG data cable or USB data cable is inserted through the 4pin, and decide whether to turn on the OTG power supply function.
5, the difference in hardware is that there is a PIN at one end of the OTG line connected with a GND ground line, so that the machine can distinguish who is the host and who is the Device peripheral, and it is impossible to distinguish the OTG line and the ordinary USB line with the appearance alone.
6, the traditional usb interface pin is: 1.vbus (5v) 2.GND3.D + 4.D –
7, OTG cable only Micro interface, a total of 5pin1.vbus2.GND3.D + 4.D-5.ID
8, USB cable running inside are 4 lines, the difference is the connector. The mobile phone or tablet uses a Micro USB connector, connects to a common USB cable, and the ID pin is suspended, so it operates in client/peripheral mode. If the ID GND is grounded, it will enter host mode.
