The difference between OTG data line and USB data line

1, USB data cable is used to connect mobile phones and computers, it can access the photos, music and other data in the phone through the computer. At the same time, because the mobile phone has its own memory or expansion card, in a sense, the mobile phone is another U disk. Of course, it is also an essential bridge for charging digital devices such as mobile phones, tablets, and MP4s.

2, OTG data cable, your mobile phone does not need to go through a PC or notebook, you can directly connect to USB devices such as U disk, mouse, keyboard, etc. through OTG data cable, which means that the mobile phone can directly connect to the U disk to find data and mouse to play games. , fast keyboard typing, camera access to the picture, that is, shoot and pass. In other words, the OTG line eliminates the need for each device to pass through the computer to communicate information, which not only expands the function of the mobile phone, but also makes it more convenient to connect with the Internet, and is more suitable for the development of this mobile Internet era. Other digital devices such as tablets that have OTG functions are also suitable.

3. The difference between the OTG line and the ordinary USB cable is 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 U disk and other devices, the main object such as the mobile phone must be given to the peripheral device such as the USB flash drive. powered by.

4. How does the mobile phone recognize the USB data cable and the OTG data cable? After disassembling the two wires, you will find that the 4pin of the USB data cable is floating, and the 4pin of the OTG data cable is shorted to the ground. The mobile phone chip should determine whether to insert the OTG data line or the USB data line through the 4th pin, and use this to decide whether to turn on the OTG power supply function.

5, the difference in hardware is: one end of the OTG line has a PIN connected to the root GND ground line, so that the machine can distinguish who is the host, who is the Device peripheral, the appearance is unable to distinguish the OTG line and the ordinary USB line .

6. The pin of the traditional usb interface has: 1. vbus (5v) 2. GND3. D+4. D-

7, OTG line only Micro interface, a total of 5pin1. vbus2. GND3. D+4. D-5. ID

8, USB cable runs inside are 4 lines, the difference is in the connector. The phone/tablet uses the Micro USB connector, connects to the normal USB cable, and the ID pin is left floating, so it operates in the client/peripheral mode. If the ID GND is grounded, it will enter the host mode.