1、Log in to the system background through the serial port，you need to use the board’s Debug interface，Interface locations and definitions are shown：
  
{{:arm:rk3399:android:ser-1.png?600|}}

* Only three pins are needed for the interface，TX、RX、GND

2、You need to use the serial pad tool
  * TX、RX and GND need to be connected to part A
  * Part B Connects to the USB port on the computer

{{:arm:rk3399:android:ser-3.png?600×356|}}

3、Hardware part connection effect diagram

{{:arm:rk3399:android:ser-tu.png?600|}}

4、Check for serial port information in the Decive Manager port of your computer

{{:arm:rk3399:android:serial-3_1-en.png?600|}}
 
5、Open Xshell create a new session，select protocol as under connection SERIAL,operation figure：

{{:arm:rk3399:android:serial-1-en.png?600|}}

6、Click serial port，the port number is the serial port number seen by the device manager，the baud rate is：1500000

{{:arm:rk3399:android:serial-2-en.png?600|}}

7、Finally click Connect,the serial port into the background

{{:arm:rk3399:android:serial-6.png?600|}}