2021-07-12-Iot2040和Iot2050 修改串口参数

IOT2040 串口表示#

Linux将所有UARTs表示为ttyS,其中 x = 0, 1 对应内部设备，2, 3对应外部设备

修改指令#

IOT2040

指令：switchserialmode

Usage: switchserialmode DEVICE [MODE [-t|--terminate]]

DEVICE          The device for which you want to switch the mode.
MODE            The mode you want to use: rs232, rs485, or rs422.
                If omitted, the current mode will be printed.

Optional arguments:
 -t, --terminate        Terminate the RS422 or RS485 bus.

例子：switchserialmode /dev/ttyS2 RS485 –terminate

IOT2050

指令：switchserialmode
It's used to set external serial port mode.
Usage:
    switchserialmode [ttyuart [options]] | [cp210x [options]] | [-m,--mode MODE]

Example:
    switchserialmode ttyuart -h
    switchserialmode cp210x -h
    switchserialmode -m,--mode <rs232 | rs485 | rs422> [-t,--terminate]
        -t,--terminate: Terminate the rs422 or rs485 bus.

指令：switchserialmode ttyuart -h

It's to operate tty serial device.
    -h,--help: display help information.
    -D,--device: specified device, like '/dev/ttyS1' etc.
    -m,--mode mode: set serial work mode, the mode can be set 'rs232' or 'rs485' or 'rs422'.
    -l,--logic level: set RTS-pin logic level when sending in rs485 mode, logic can be set '0' or '1'.
    -d,--display: display the current mode of ttyuart

例子：

1. 查看：switchserialmode ttyuart -D /dev/ttyS2 -d
2. 设置：switchserialmode ttyuart -D /dev/ttyS2 -m RS485 -t

设置开机启动#

IOT2040#

1. 创建文件：vi /etc/init.d/changetty.sh
2. chmod 755 /etc/init.d/changetty.sh
3. 修改文件

#! /bin/sh
# /etc/init.d/changetty.sh

### BEGIN INIT INFO
# Provides:          changetty
# Required-Start:    
# Should-Start:
# Required-Stop:     
# Should-Stop:
# Default-Start:     2 3 4 5
# Default-Stop:      0 1 6
# Short-Description: changetty
### END INIT INFO

echo '/etc/init.d/changetty.sh'
switchserialmode /dev/ttyS2 RS485 --terminate
exit 0

4. 将启动脚本链接到 /ect/rcX.d

ln -s /etc/init.d/changetty.sh  /etc/rc2.d/S20changetty
ln -s /etc/init.d/changetty.sh  /etc/rc3.d/S20changetty
ln -s /etc/init.d/changetty.sh  /etc/rc4.d/S20changetty
ln -s /etc/init.d/changetty.sh  /etc/rc5.d/S20changetty

5. 执行并替换文件

switchserialmode /dev/ttyS2 RS485 --terminate
switchserialmode /dev/ttyS2 RS422 --terminate
switchserialmode /dev/ttyS2 RS232

sed -i s/.*switchserialmode.*/'switchserialmode \/dev\/ttyS2 RS485 --terminate'/ /etc/init.d/changetty.sh

IOT2050#

1. 在/root 目录中创建 changetty.py

#! /usr/bin/python3

import sys
import subprocess
import json
from collections import OrderedDict


class Process:
    def __init__(self):
        self.configureFile = '/etc/board-configuration.json'
        self.config = self.getConfig()

    def getConfig(self):
        with open(self.configureFile, 'r') as f:
            config = json.load(f, object_pairs_hook=OrderedDict)
            return config

    def saveConfig(self, jsonSrc):
        with open(self.configureFile, 'w') as f:
            json.dump(jsonSrc, f, indent=4, separators=(',', ': '))

    def setBasicBoard(self, mode, terminateStatus):
        command = 'switchserialmode ttyuart -D /dev/ttyS2 -m ' + mode
        subprocess.call(command, shell=True)
        self.config['User_configuration']['External_Serial_Init_Mode'] = mode
        if terminateStatus == 'on' or terminateStatus == 'off':
            self.config['User_configuration']['External_Serial_Terminate'] = terminateStatus
        self.saveConfig(self.config)


def main(argv):
    try:
        process = Process()

        print(argv[1])  # mode
        print(argv[2])  # terminateStatus
        process.setBasicBoard(argv[1], argv[2])
    except:
        pass
    finally:
        print('end world')
        return ''


if __name__ == '__main__':
    main(sys.argv)

2. 在NodeRed 中调用脚本

python changetty.py RS485 'on'
python changetty.py RS422 'on'
python changetty.py RS232 'on'