How to use UART

Overview

The Android/Linux UART/serial port access from user is through the tty-devices. The tty-devices have different names depending on UART driver on different board.

RS-485

RS-485 uses half-duplex communication, which means that one medium is shared for transmitting and receiving data. Therefore the system needs to control the RS-485 transceiver's transmit mode. Usually the UART RTS signal is used to switch the transmitter on and off.

Boards

EPC-4680 Borad

<tbody> </tbody>

COM Name	Device Node	Remark
COM0	/dev/ttyS0	BT
COM1	/dev/ttyS2	Debug Port
COM2	/dev/ttyS4	485
COM3	/dev/ttyUSB0
COM4	/dev/ttyUSB1
COM5	/dev/ttyS1
COM6	/dev/ttyS3

 

 

Note : 

1. Only COM1、COM2、COM3、COM4、COM5 and COM6 are designed for custom using.

2. Only COM4 support RSB485.

3. COM2 is designed as debug port default.