【2023 DigiKey大赛参与奖】BeagleBone_Green开发板基于Ibserialport进行串口开发

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【2023 DigiKey大赛参与奖】BeagleBone_Green开发板基于Ibserialport进行串口开发 [复制链接]

 

本文转自本人公众号文章

发板基于Ibserialport进行串口开发

https://mp.weixin.qq.com/s/14_pt_OkyrNTEPGlB9gWBw 玩板系列之三:BeagleBone_Green开发板基于Ibserialport进行串口开发

一. 前言

串口是嵌入式开发最常用的通讯接口，需要经常使用，一个好的串口开发库可以比自己直接操作设备文件读写，更方便简单高效。这里分享一款比较好的跨平台的串口库libserialport以及在本开发板上的应用实例。

二. 使能串口

查看设备树

debian@BeagleBone:~$ ls /lib/firmware/BB-UART*

/lib/firmware/BB-UART1-00A0.dtbo

/lib/firmware/BB-UART1-RTSCTS-00A0.dtbo

/lib/firmware/BB-UART2-00A0.dtbo

/lib/firmware/BB-UART2-00A1.dtbo

/lib/firmware/BB-UART2-RTSCTS-00A0.dtbo

/lib/firmware/BB-UART3-00A0.dtbo

/lib/firmware/BB-UART4-00A0.dtbo

/lib/firmware/BB-UART4-E-INK.dtbo

/lib/firmware/BB-UART4-RS485-00A0.dtbo

/lib/firmware/BB-UART4-RTSCTS-00A0.dtbo

/lib/firmware/BB-UART5-00A0.dtbo

/lib/firmware/BB-UART5-RTSCTS-00A0.dtbo

debian@BeagleBone:~$

查看设备树内容

cat /lib/firmware/BB-UART1-00A0.dtbo

sudo nano /boot/uEnv.txt添加如下内容使能设备树，重启

# UART 1

uboot_overlay_addr0=/lib/firmware/BB-UART1-00A0.dtbo

# UART 2

uboot_overlay_addr1=/lib/firmware/BB-UART2-00A0.dtbo

# UART 4

uboot_overlay_addr2=/lib/firmware/BB-UART4-00A0.dtbo

# UART 5

uboot_overlay_addr3=/lib/firmware/BB-UART5-00A0.dtbo

# UART 3 (only TX). Note that in "uboot_overlay_addrX", the X need not be = UART id

uboot_overlay_addr4=/lib/firmware/BB-UART3-00A0.dtbo

三. 使用Ibserialport源码构建应用

下载代码

git clone git://sigrok.org/libserialport

位于libserialport同级

复制测试代码

cp libserialport/examples/send_receive.c .

新建config.h文件可以是空文件

需要文件

libserialport.h

libserialport_internal.h

serialport.c

timing.c

linux.c

linux_termios.c

linux_termios.h

编译

gcc libserialport/serialport.c libserialport/timing.c libserialport/linux.c libserialport/linux_termios.c send_receive.c -o send_receive -Ilibserialport/ -I. -DSP_PRIV=

运行测试

sudo cat /proc/tty/drivers

debian@BeagleBone:~$ sudo cat /proc/tty/drivers

/dev/tty /dev/tty        5       0 system:/dev/tty

/dev/console /dev/console    5       1 system:console

/dev/ptmx /dev/ptmx       5       2 system

/dev/vc/0 /dev/vc/0       4       0 system:vtmaster

g_serial /dev/ttyGS    242 0-7 serial

serial /dev/ttyS       4 64-69 serial

pty_slave /dev/pts      136 0-1048575 pty:slave

pty_master /dev/ptm      128 0-1048575 pty:master

unknown /dev/tty        4 1-63 console

debian@BeagleBone:~$

对应

debian@BeagleBone:~$ ls /dev/ttyS

ttyS0 ttyS1  ttyS2  ttyS3  ttyS4  ttyS5 

 

 

我们使用UART4测试，短接UART4的RXD和TXD

debian@BeagleBone:~$ ./send_receive /dev/ttyS4

Looking for port /dev/ttyS4.

Opening port.

Setting port to 9600 8N1, no flow control.

Sending 'Hello!' (6 bytes) on port /dev/ttyS4.

Sent 6 bytes successfully.

Receiving 6 bytes on port /dev/ttyS4.

Received 6 bytes successfully.

Received 'Hello!'.

debian@BeagleBone:~$

四. 总结

基于libserial提供的阻塞和非阻塞的接口,可以快速的进行串口应用的开发。

Jacktang

libserial提供的阻塞和非阻塞的接口,可以快速的进行串口应用的开发，完美