Difference between revisions of "How to use UART RK3588"

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(Created page with " = '''Overview''' = <font color="#000000">The Android/Linux UART/serial port access from user is through the tty-devices. The tty-devices have different names depending on UA...")
 
(→‎AOM-3821 Borad)
 
(6 intermediate revisions by 2 users not shown)
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| COM3
 
| COM3
 
| /dev/ttyS9
 
| /dev/ttyS9
 +
| RS232 4-wire
 +
|}
 +
 +
'''Note&nbsp;:&nbsp;'''
 +
 +
&nbsp;
 +
 +
== ASR-A501&nbsp;Borad ==
 +
 +
'''Main Board'''
 +
 +
{| border="1" cellpadding="1" cellspacing="1"
 +
|-
 +
| '''COM Name'''
 +
| '''Device Node'''
 +
| '''Remark'''
 +
|-
 +
| COM1
 +
| /dev/ttyS6
 +
| RS232 4-wire or RS485
 +
|-
 +
| COM2
 +
| /dev/ttyS5
 +
| RS485
 +
|-
 +
| COM3
 +
| /dev/ttyS9
 +
| RS232 4-wire or RS485
 +
|-
 +
| COM4
 +
| /dev/ttyS3
 +
| RS485
 +
|}
 +
 +
'''Note&nbsp;:&nbsp;''' 1. Only COM1 and COM3 support RS232 4-wire.
 +
 +
2. The COM1 and COM3 default mode is RS232 4-wire.
 +
 +
&nbsp;
 +
 +
'''EG90/RM01/RM02'''
 +
 +
{| border="1" cellpadding="1" cellspacing="1"
 +
|-
 +
| '''COM Name'''
 +
| '''Device Node'''
 +
| '''Remark'''
 +
|-
 +
| COM1
 +
| /dev/ttyS7
 +
| RS232 2-wire
 +
|}
 +
 +
'''Note&nbsp;:&nbsp;'''
 +
 +
&nbsp;
 +
 +
 +
== AOM-3821&nbsp;Borad ==
 +
 +
{| border="1" cellpadding="1" cellspacing="1"
 +
|-
 +
| '''COM Name'''
 +
| '''Device Node'''
 +
| '''Remark'''
 +
|-
 +
| COM1
 +
| /dev/ttyS0
 +
| RS232 2-wire
 +
|-
 +
| M.2 E-Key
 +
| /dev/ttyS6
 
| RS232 4-wire
 
| RS232 4-wire
 
|}
 
|}
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Then you can&nbsp;input the following cammand to config UART mode.
 
Then you can&nbsp;input the following cammand to config UART mode.
  
−
== Config Uart Mode ==
+
== Config Uart coming from cpu ==
 +
 
 +
'''RS485 Mode（Taking ASR-A501 for example）:'''
 +
<pre>setenv uart_mode_cpu 6:1,9:1
 +
saveenv
 +
reset
 +
</pre>
  
−
Only ttyUSB2 and ttyUSB3 support RS485 mode.
+
'''RS232 Mode（Taking ASR-A501 for example）:'''
 +
<pre>setenv uart_mode_cpu 6:0,9:0
 +
saveenv
 +
reset
 +
</pre>
 +
 
 +
'''Note&nbsp;:'''
 +
 
 +
The default value is RS232 for ASR-A501 ttyS6 and ttyS9.
 +
 
 +
Above command "uart_mode_cpu 6:1,9:1", 6:1 means set ttyS6 to RS485(0 means to RS232; 1 means to RS485).
 +
 
 +
If you just want ttyS6(or ttyS9)to be RS485 mode, please change "6:1,9:1"to "6:1,9:0"(or "6:0,9:1").
 +
 
 +
== Config Uart coming from cp2108 ==
  
 
'''RS485 Mode:&nbsp;'''
 
'''RS485 Mode:&nbsp;'''
Line 69: Line 161:
  
 
'''Note&nbsp;:&nbsp;'''
 
'''Note&nbsp;:&nbsp;'''
−
 
−
The default value is RS232.&nbsp;
 
−
 
−
Cp210x support four port, but RSB4810 Only ttyUSB2 and ttyUSB3 support RS485 mode.
 
  
 
Above command "setenv uart_mode 0x0c", 0x0c means set bit2(ttyUSB2) and bit3(ttyUSB3) to 1 (0 means to RS232; 1 means to RS485).
 
Above command "setenv uart_mode 0x0c", 0x0c means set bit2(ttyUSB2) and bit3(ttyUSB3) to 1 (0 means to RS232; 1 means to RS485).
  
 
If you just want ttyUSB2 (or ttyUSB3)to be RS485 mode, please change 0x0c to 0x04 (or 0x08).
 
If you just want ttyUSB2 (or ttyUSB3)to be RS485 mode, please change 0x0c to 0x04 (or 0x08).

Latest revision as of 06:38, 28 April 2025

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

ROM-6881 Borad

COM Name Device Node Remark
COM1 /dev/ttyS0 RS232 2-wire
COM2 /dev/ttyS6 RS232 4-wire
COM3 /dev/ttyS9 RS232 4-wire

Note : 

 

ASR-A501 Borad

Main Board

COM Name Device Node Remark
COM1 /dev/ttyS6 RS232 4-wire or RS485
COM2 /dev/ttyS5 RS485
COM3 /dev/ttyS9 RS232 4-wire or RS485
COM4 /dev/ttyS3 RS485

Note :  1. Only COM1 and COM3 support RS232 4-wire.

2. The COM1 and COM3 default mode is RS232 4-wire.

 

EG90/RM01/RM02

COM Name Device Node Remark
COM1 /dev/ttyS7 RS232 2-wire

Note : 

 


AOM-3821 Borad

COM Name Device Node Remark
COM1 /dev/ttyS0 RS232 2-wire
M.2 E-Key /dev/ttyS6 RS232 4-wire

Note : 

 

How to config RS232 or RS485 mode

Enter U-boot interrupt mode

Connect device to debug port, and open debug console. See more : How_to_debug.

Press "ctrl + c" key before power up the device, until get the following information on debug console :  

Hit any key to stop autoboot: 0
=> <INTERRUPT>
=>

Then you can input the following cammand to config UART mode.

Config Uart coming from cpu

RS485 Mode（Taking ASR-A501 for example）: 

setenv uart_mode_cpu 6:1,9:1
saveenv
reset

RS232 Mode（Taking ASR-A501 for example）: 

setenv uart_mode_cpu 6:0,9:0
saveenv
reset

Note :

The default value is RS232 for ASR-A501 ttyS6 and ttyS9.

Above command "uart_mode_cpu 6:1,9:1", 6:1 means set ttyS6 to RS485(0 means to RS232; 1 means to RS485).

If you just want ttyS6(or ttyS9)to be RS485 mode, please change "6:1,9:1"to "6:1,9:0"(or "6:0,9:1").

Config Uart coming from cp2108

RS485 Mode:  

setenv uart_mode 0x0c
saveenv
reset

RS232 Mode:  

setenv uart_mode 0x00
saveenv
reset

Note : 

Above command "setenv uart_mode 0x0c", 0x0c means set bit2(ttyUSB2) and bit3(ttyUSB3) to 1 (0 means to RS232; 1 means to RS485).

If you just want ttyUSB2 (or ttyUSB3)to be RS485 mode, please change 0x0c to 0x04 (or 0x08).

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