Commonly used USB data cable and OTG data cable difference
In daily life, we use a lot of electronic products, such as mobile phones, computers, tablets, game consoles, digital cameras, etc. These products need to be charged. The micro USB data cable is the charging cable that we use most daily. USB data cable can not only charge, but also transfer data, connect mobile phone and computer with USB, access mobile phone files and pictures through computer, or download files and pictures from the computer to the mobile phone while charging the mobile phone. Is it very Convenient.
Speaking of transmitting data, of course, not only a USB data cable, but also the OTG data cable announced by the USB Implementers Forum in 2001 can be connected between different electronic products or mobile devices for data exchange, which is more advantageous than data lines. . Because the mobile devices we use are connected to the PC through the USB data cable, the data can be exchanged under the control of the PC. Once the PC is disconnected, the mobile device cannot perform the transfer operation because there is no device that can replace the host such as the PC.
The appearance of the OTG data line changes the state in which only the PC can exchange data between the mobile devices. The OTG data line does not need to be connected to the PC, and the mobile devices are connected through the OTG data line, such as the mobile phone through the OTG data line and the U disk, the mouse, Keyboard, digital camera and other connections can directly access files, expand functions and data transmission. Connect U disk to view the data uploading and downloading files and pictures, connect the mouse and keyboard to play games and type, connect the digital camera to view pictures, upload and download pictures, It is easy to use when you leave the PC.
When the mobile phone connects to the external device through OTG, the mobile phone needs to supply power to the external device. How does the mobile phone recognize the OTG data cable and the USB data cable? After unpacking the two wires, you will see that the 4th pin of the USB cable is floating. The 4pin of the OTG cable is shorted to the ground. The phone chip should be the USB cable or OTG inserted through the 4pin. The data line, and use this to decide whether to turn on the OTG power supply. The difference in hardware is that there is a PIN on one end of the OTG line and a GND ground line is connected. Let the machine distinguish which host is the host (HOST). That is an external device. The appearance cannot be that the USB data cable cannot be identified. The difference between OTG data lines.
20170511094307_7412.jpg
The OTG data line has only the micro interface, which is 5 pins in total:
1.vbus 2.GND 3.D+4.D-5.ID
20170511094623_8960.jpg
USB data cable interface PIN has:
1.vbus(5v)2.GND 3.D+4.D-5.ID Pin is left floating
USB cable is running 4 lines inside, and OTG data line is only in the connector, mobile phone, tablet are microUSB transfer ordinary USB data line, IDpin is floating, so it operates in client/peripheral mode; If the ID GND is grounded, it will enter hostmode (host mode). Therefore, the difference between the USB data line and the OTG data line is that the USB data line requires the mobile device to connect to the PC to transmit data and consult data in a fixed environment, and the OTG data line can be connected to different mobile devices for data in a freely movable environment. Transmission and data review. The USB OTG standard adds power management (power saving) to the USB 2.0 standard. It allows the device to operate as both a host and a peripheral (a dual-purpose OTG) and provides some Host detection capability, supporting Host Command Protocol (HNP) and Session Request Protocol (SRP).
Speaking of transmitting data, of course, not only a USB data cable, but also the OTG data cable announced by the USB Implementers Forum in 2001 can be connected between different electronic products or mobile devices for data exchange, which is more advantageous than data lines. . Because the mobile devices we use are connected to the PC through the USB data cable, the data can be exchanged under the control of the PC. Once the PC is disconnected, the mobile device cannot perform the transfer operation because there is no device that can replace the host such as the PC.
The appearance of the OTG data line changes the state in which only the PC can exchange data between the mobile devices. The OTG data line does not need to be connected to the PC, and the mobile devices are connected through the OTG data line, such as the mobile phone through the OTG data line and the U disk, the mouse, Keyboard, digital camera and other connections can directly access files, expand functions and data transmission. Connect U disk to view the data uploading and downloading files and pictures, connect the mouse and keyboard to play games and type, connect the digital camera to view pictures, upload and download pictures, It is easy to use when you leave the PC.
When the mobile phone connects to the external device through OTG, the mobile phone needs to supply power to the external device. How does the mobile phone recognize the OTG data cable and the USB data cable? After unpacking the two wires, you will see that the 4th pin of the USB cable is floating. The 4pin of the OTG cable is shorted to the ground. The phone chip should be the USB cable or OTG inserted through the 4pin. The data line, and use this to decide whether to turn on the OTG power supply. The difference in hardware is that there is a PIN on one end of the OTG line and a GND ground line is connected. Let the machine distinguish which host is the host (HOST). That is an external device. The appearance cannot be that the USB data cable cannot be identified. The difference between OTG data lines.
20170511094307_7412.jpg
The OTG data line has only the micro interface, which is 5 pins in total:
1.vbus 2.GND 3.D+4.D-5.ID
20170511094623_8960.jpg
USB data cable interface PIN has:
1.vbus(5v)2.GND 3.D+4.D-5.ID Pin is left floating
USB cable is running 4 lines inside, and OTG data line is only in the connector, mobile phone, tablet are microUSB transfer ordinary USB data line, IDpin is floating, so it operates in client/peripheral mode; If the ID GND is grounded, it will enter hostmode (host mode). Therefore, the difference between the USB data line and the OTG data line is that the USB data line requires the mobile device to connect to the PC to transmit data and consult data in a fixed environment, and the OTG data line can be connected to different mobile devices for data in a freely movable environment. Transmission and data review. The USB OTG standard adds power management (power saving) to the USB 2.0 standard. It allows the device to operate as both a host and a peripheral (a dual-purpose OTG) and provides some Host detection capability, supporting Host Command Protocol (HNP) and Session Request Protocol (SRP).
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