一、UART 协议
UART详解_sternlycore的博客-CSDN博客
二、UART 和 TTY 关系
基于Linux的tty架构及UART驱动详解 - 一口Linux - 博客园 (cnblogs.com)
三、Linux UART 驱动框架中重要对象
1、UART 驱动
struct uart_driver {
struct module *owner;
const char *driver_name;
const char *dev_name;
int major;
int minor;
int nr;
struct console *cons;
/*
* these are private; the low level driver should not
* touch these; they should be initialised to NULL
*/
struct uart_state *state;
struct tty_driver *tty_driver;
};
每个串口驱动都需要定义一个 uart_driver，加载驱动时向系统注册这个 uart_driver，注销驱动时注销掉注册的 uart_driver。
2、UART 控制器
struct uart_port {
spinlock_t lock; /* port lock */
unsigned long iobase; /* in/out[bwl] */
unsigned char __iomem *membase; /* read/write[bwl] */
unsigned int (*serial_in)(struct uart_port *, int);
void (*serial_out)(struct uart_port *, int, int);
void (*set_termios)(struct uart_port *,
struct ktermios *new,
struct ktermios *old);
void (*set_mctrl)(struct uart_port *, unsigned int);
int (*startup)(struct uart_port *port);
void (*shutdown)(struct uart_port *port);
void (*throttle)(struct uart_port *port);
void (*unthrottle)(struct uart_port *port);
int (*handle_irq)(struct uart_port *);
void (*pm)(struct uart_port *, unsigned int state,
unsigned int old);
void (*handle_break)(struct uart_port *);
int (*rs485_config)(struct uart_port *,
struct serial_rs485 *rs485);
unsigned int irq; /* irq number */
unsigned long irqflags; /* irq flags */
unsigned int uartclk; /* base uart clock */
unsigned int fifosize; /* tx fifo size */
unsigned char x_char; /* xon/xoff char */
unsigned char regshift; /* reg offset shift */
unsigned char iotype; /* io access style */
unsigned char unused1;
#define UPIO_PORT (SERIAL_IO_PORT) /* 8b I/O port access */
#define UPIO_HUB6 (SERIAL_IO_HUB6) /* Hub6 ISA card */
#define UPIO_MEM (SERIAL_IO_MEM) /* 8b MMIO access */
#define UPIO_MEM32 (SERIAL_IO_MEM32) /* 32b little endian */
#define UPIO_AU (SERIAL_IO_AU) /* Au1x00 and RT288x type IO */
#define UPIO_TSI (SERIAL_IO_TSI) /* Tsi108/109 type IO */
#define UPIO_MEM32BE (SERIAL_IO_MEM32BE) /* 32b big endian */
unsigned int read_status_mask; /* driver specific */
unsigned int ignore_status_mask; /* driver specific */
struct uart_state *state; /* pointer to parent state */
struct uart_icount icount; /* statistics */
struct console *cons; /* struct console, if any */
#if defined(CONFIG_SERIAL_CORE_CONSOLE) || defined(SUPPORT_SYSRQ)
unsigned long sysrq; /* sysrq timeout */
#endif
/* flags must be updated while holding port mutex */
upf_t flags;
/*
* These flags must be equivalent to the flags defined in
* include/uapi/linux/tty_flags.h which are the userspace definitions
* assigned from the serial_struct flags in uart_set_info()
* [for bit definitions in the UPF_CHANGE_MASK]
*
* Bits [0..UPF_LAST_USER] are userspace defined/visible/changeable
* except bit 15 (UPF_NO_TXEN_TEST) which is masked off.
* The remaining bits are serial-core specific and not modifiable by
* userspace.
*/
#define UPF_FOURPORT ((__force upf_t) ASYNC_FOURPORT /* 1 */ )
#define UPF_SAK ((__force upf_t) ASYNC_SAK /* 2 */ )
#define UPF_SPD_HI ((__force upf_t) ASYNC_SPD_HI /* 4 */ )
#define UPF_SPD_VHI ((__force upf_t) ASYNC_SPD_VHI /* 5 */ )
#define UPF_SPD_CUST ((__force upf_t) ASYNC_SPD_CUST /* 0x0030 */ )
#define UPF_SPD_WARP ((__force upf_t) ASYNC_SPD_WARP /* 0x1010 */ )
#define UPF_SPD_MASK ((__force upf_t) ASYNC_SPD_MASK /* 0x1030 */ )
#define UPF_SKIP_TEST ((__force upf_t) ASYNC_SKIP_TEST /* 6 */ )
#define UPF_AUTO_IRQ ((__force upf_t) ASYNC_AUTO_IRQ /* 7 */ )
#define UPF_HARDPPS_CD ((__force upf_t) ASYNC_HARDPPS_CD /* 11 */ )
#define UPF_SPD_SHI ((__force upf_t) ASYNC_SPD_SHI /* 12 */ )
#define UPF_LOW_LATENCY ((__force upf_t) ASYNC_LOW_LATENCY /* 13 */ )
#define UPF_BUGGY_UART ((__force upf_t) ASYNC_BUGGY_UART /* 14 */ )
#define UPF_NO_TXEN_TEST ((__force upf_t) (1 << 15))
#define UPF_MAGIC_MULTIPLIER ((__force upf_t) ASYNC_MAGIC_MULTIPLIER /* 16 */ )
/* Port has hardware-assisted h/w flow control */
#define UPF_AUTO_CTS ((__force upf_t) (1 << 20))
#define UPF_AUTO_RTS ((__force upf_t) (1 << 21))
#define UPF_HARD_FLOW ((__force upf_t) (UPF_AUTO_CTS | UPF_AUTO_RTS))
/* Port has hardware-assisted s/w flow control */
#define UPF_SOFT_FLOW ((__force upf_t) (1 << 22))
#define UPF_CONS_FLOW ((__force upf_t) (1 << 23))
#define UPF_SHARE_IRQ ((__force upf_t) (1 << 24))
#define UPF_EXAR_EFR ((__force upf_t) (1 << 25))
#define UPF_BUG_THRE ((__force upf_t) (1 << 26))
/* The exact UART type is known and should not be probed. */
#define UPF_FIXED_TYPE ((__force upf_t) (1 << 27))
#define UPF_BOOT_AUTOCONF ((__force upf_t) (1 << 28))
#define UPF_FIXED_PORT ((__force upf_t) (1 << 29))
#define UPF_DEAD ((__force upf_t) (1 << 30))
#define UPF_IOREMAP ((__force upf_t) (1 << 31))
#define __UPF_CHANGE_MASK 0x17fff
#define UPF_CHANGE_MASK ((__force upf_t) __UPF_CHANGE_MASK)
#define UPF_USR_MASK ((__force upf_t) (UPF_SPD_MASK|UPF_LOW_LATENCY))
#if __UPF_CHANGE_MASK > ASYNC_FLAGS
#error Change mask not equivalent to userspace-visible bit defines
#endif
/*
* Must hold termios_rwsem, port mutex and port lock to change;
* can hold any one lock to read.
*/
upstat_t status;
#define UPSTAT_CTS_ENABLE ((__force upstat_t) (1 << 0))
#define UPSTAT_DCD_ENABLE ((__force upstat_t) (1 << 1))
#define UPSTAT_AUTORTS ((__force upstat_t) (1 << 2))
#define UPSTAT_AUTOCTS ((__force upstat_t) (1 << 3))
#define UPSTAT_AUTOXOFF ((__force upstat_t) (1 << 4))
int hw_stopped; /* sw-assisted CTS flow state */
unsigned int mctrl; /* current modem ctrl settings */
unsigned int timeout; /* character-based timeout */
unsigned int type; /* port type */
const struct uart_ops *ops;
unsigned int custom_divisor;
unsigned int line; /* port index */
unsigned int minor;
resource_size_t mapbase; /* for ioremap */
resource_size_t mapsize;
struct device *dev; /* parent device */
unsigned char hub6; /* this should be in the 8250 driver */
unsigned char suspended;
unsigned char irq_wake;
unsigned char unused[2];
struct attribute_group *attr_group; /* port specific attributes */
const struct attribute_group **tty_groups; /* all attributes (serial core use only) */
struct serial_rs485 rs485;
void *private_data; /* generic platform data pointer */
};
Linux 中使用 struct uart_port 描述硬件信息。
3、UART 操作集
/*
* This structure describes all the operations that can be done on the
* physical hardware. See Documentation/serial/driver for details.
*/
struct uart_ops {
unsigned int (*tx_empty)(struct uart_port *);
void (*set_mctrl)(struct uart_port *, unsigned int mctrl);
unsigned int (*get_mctrl)(struct uart_port *);
void (*stop_tx)(struct uart_port *);
void (*start_tx)(struct uart_port *);
void (*throttle)(struct uart_port *);
void (*unthrottle)(struct uart_port *);
void (*send_xchar)(struct uart_port *, char ch);
void (*stop_rx)(struct uart_port *);
void (*enable_ms)(struct uart_port *);
void (*break_ctl)(struct uart_port *, int ctl);
int (*startup)(struct uart_port *);
void (*shutdown)(struct uart_port *);
void (*flush_buffer)(struct uart_port *);
void (*set_termios)(struct uart_port *, struct ktermios *new,
struct ktermios *old);
void (*set_ldisc)(struct uart_port *, struct ktermios *);
void (*pm)(struct uart_port *, unsigned int state,
unsigned int oldstate);
/*
* Return a string describing the type of the port
*/
const char *(*type)(struct uart_port *);
/*
* Release IO and memory resources used by the port.
* This includes iounmap if necessary.
*/
void (*release_port)(struct uart_port *);
/*
* Request IO and memory resources used by the port.
* This includes iomapping the port if necessary.
*/
int (*request_port)(struct uart_port *);
void (*config_port)(struct uart_port *, int);
int (*verify_port)(struct uart_port *, struct serial_struct *);
int (*ioctl)(struct uart_port *, unsigned int, unsigned long);
#ifdef CONFIG_CONSOLE_POLL
int (*poll_init)(struct uart_port *);
void (*poll_put_char)(struct uart_port *, unsigned char);
int (*poll_get_char)(struct uart_port *);
#endif
};
四、UART 驱动编写思路
Linux 下 UART 一般都编写好，根据设备树找到相关驱动分析即可。
五、imx6ull 下 UART 驱动分析
文档路径：drivers\tty\serial\imx.c。
1、驱动框架
static struct uart_driver imx_reg = {
.owner = THIS_MODULE,
.driver_name = DRIVER_NAME,
.dev_name = DEV_NAME,
.major = SERIAL_IMX_MAJOR,
.minor = MINOR_START,
.nr = ARRAY_SIZE(imx_ports), // imx_ports 封装 struct uart_port
.cons = IMX_CONSOLE,
};
static struct platform_driver serial_imx_driver = {
.probe = serial_imx_probe,
.remove = serial_imx_remove,
.suspend = serial_imx_suspend,
.resume = serial_imx_resume,
.id_table = imx_uart_devtype,
.driver = {
.name = "imx-uart",
.of_match_table = imx_uart_dt_ids,
},
};
static int __init imx_serial_init(void)
{
int ret = uart_register_driver(&imx_reg);
if (ret)
return ret;
ret = platform_driver_register(&serial_imx_driver);
if (ret != 0)
uart_unregister_driver(&imx_reg);
return ret;
}
static void __exit imx_serial_exit(void)
{
platform_driver_unregister(&serial_imx_driver);
uart_unregister_driver(&imx_reg);
}
1、UART 驱动使用 platform 驱动框架。
2、在加载驱动时注册 UART 驱动。
2、初始化
见 serial_imx_probe 函数。
3、注销
见 serial_imx_remove 函数。
六、添加设备树
1、UART 设备树相关说明
见文档：Documentation\devicetree\bindings\serial\fsl-imx-uart.txt。
2、确定使用 UART
通过原理图可以确定，使用接口为 uart3。
3、添加 pinctrl 子系统相关配置
pinctrl_uart3: uart3grp {
fsl,pins = <
MX6UL_PAD_UART3_TX_DATA__UART3_DCE_TX 0X1b0b1
MX6UL_PAD_UART3_RX_DATA__UART3_DCE_RX 0X1b0b1
>;
};
4、在 uart3 下追加配置
&uart3 {
pinctrl-names = "default";
pinctrl-0 = <&pinctrl_uart3>;
status = "okay";
};
5、编译设备树
onlylove@ubuntu:~/my/linux/linux-imx-4.1.15$ make dtbs
CHK include/config/kernel.release
CHK include/generated/uapi/linux/version.h
CHK include/generated/utsrelease.h
make[1]: 'include/generated/mach-types.h' is up to date.
CHK include/generated/bounds.h
CHK include/generated/asm-offsets.h
CALL scripts/checksyscalls.sh
DTC arch/arm/boot/dts/imx6ull-alientek-emmc.dtb
DTC arch/arm/boot/dts/imx6ull-alientek-nand.dtb
onlylove@ubuntu:~/my/linux/linux-imx-4.1.15$
6、测试
# pwd
/proc/device-tree/soc/aips-bus@02100000
# ls
#address-cells lcdif@021c8000 serial@021f0000
#size-cells mmdc@021b0000 serial@021f4000
adc@02198000 name serial@021fc000
compatible ocotp-ctrl@021bc000 usb@02184000
csi@021c4000 pxp@021cc000 usb@02184200
csu@021c0000 qspi@021e0000 usbmisc@02184800
ethernet@02188000 ranges usdhc@02190000
i2c@021a0000 reg usdhc@02194000
i2c@021a4000 romcp@021ac000 weim@021b8000
i2c@021a8000 serial@021e8000
i2c@021f8000 serial@021ec000
# cd serial@021ec000/
# ls
clock-names dma-names name reg
clocks dmas pinctrl-0 status
compatible interrupts pinctrl-names
# cat compatible
fsl,imx6ul-uartfsl,imx6q-uartfsl,imx21-uart#
#
七、驱动编写
uart 相关驱动 Linux 内核已添加，不需要我们编写。
# ls /dev/ttymxc* -l
crw------- 1 root root 207, 16 Jan 1 05:59 /dev/ttymxc0
crw-rw---- 1 root root 207, 18 Jan 1 00:00 /dev/ttymxc2
#
通过以上消息，uart3 驱动加载成功，uart3 在应用层映射为 ttymxc2。
八、应用编写
1、概述
在 Linux 下 UART 驱动和 tty 关系密切，在应用层使用 UART 是需特别注意，否则一些特殊字符传输可能有问题。
2、程序
/***************************************************************
Copyright © ALIENTEK Co., Ltd. 1998-2021. All rights reserved.
文件名 : uart_test.c
作者 : 邓涛
版本 : V1.0
描述 : 串口在原始模式下进行数据传输--应用程序示例代码
其他 : 无
论坛 : www.openedv.com
日志 : 初版 V1.0 2021/7/20 邓涛创建
***************************************************************/
#define _GNU_SOURCE //在源文件开头定义_GNU_SOURCE宏
#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <sys/ioctl.h>
#include <errno.h>
#include <string.h>
#include <signal.h>
#include <termios.h>
typedef struct uart_hardware_cfg {
unsigned int baudrate; /* 波特率 */
unsigned char dbit; /* 数据位 */
char parity; /* 奇偶校验 */
unsigned char sbit; /* 停止位 */
} uart_cfg_t;
static struct termios old_cfg; //用于保存终端的配置参数
static int fd; //串口终端对应的文件描述符
/**
** 串口初始化操作
** 参数device表示串口终端的设备节点
**/
static int uart_init(const char *device)
{
/* 打开串口终端 */
fd = open(device, O_RDWR | O_NOCTTY);
if (0 > fd) {
fprintf(stderr, "open error: %s: %s\n", device, strerror(errno));
return -1;
}
/* 获取串口当前的配置参数 */
if (0 > tcgetattr(fd, &old_cfg)) {
fprintf(stderr, "tcgetattr error: %s\n", strerror(errno));
close(fd);
return -1;
}
return 0;
}
/**
** 串口配置
** 参数cfg指向一个uart_cfg_t结构体对象
**/
static int uart_cfg(const uart_cfg_t *cfg)
{
struct termios new_cfg = {0}; //将new_cfg对象清零
speed_t speed;
/* 设置为原始模式 */
cfmakeraw(&new_cfg);
/* 使能接收 */
new_cfg.c_cflag |= CREAD;
/* 设置波特率 */
switch (cfg->baudrate) {
case 1200: speed = B1200;
break;
case 1800: speed = B1800;
break;
case 2400: speed = B2400;
break;
case 4800: speed = B4800;
break;
case 9600: speed = B9600;
break;
case 19200: speed = B19200;
break;
case 38400: speed = B38400;
break;
case 57600: speed = B57600;
break;
case 115200: speed = B115200;
break;
case 230400: speed = B230400;
break;
case 460800: speed = B460800;
break;
case 500000: speed = B500000;
break;
default: //默认配置为115200
speed = B115200;
printf("default baud rate: 115200\n");
break;
}
if (0 > cfsetspeed(&new_cfg, speed)) {
fprintf(stderr, "cfsetspeed error: %s\n", strerror(errno));
return -1;
}
/* 设置数据位大小 */
new_cfg.c_cflag &= ~CSIZE; //将数据位相关的比特位清零
switch (cfg->dbit) {
case 5:
new_cfg.c_cflag |= CS5;
break;
case 6:
new_cfg.c_cflag |= CS6;
break;
case 7:
new_cfg.c_cflag |= CS7;
break;
case 8:
new_cfg.c_cflag |= CS8;
break;
default: //默认数据位大小为8
new_cfg.c_cflag |= CS8;
printf("default data bit size: 8\n");
break;
}
/* 设置奇偶校验 */
switch (cfg->parity) {
case 'N': //无校验
new_cfg.c_cflag &= ~PARENB;
new_cfg.c_iflag &= ~INPCK;
break;
case 'O': //奇校验
new_cfg.c_cflag |= (PARODD | PARENB);
new_cfg.c_iflag |= INPCK;
break;
case 'E': //偶校验
new_cfg.c_cflag |= PARENB;
new_cfg.c_cflag &= ~PARODD; /* 清除PARODD标志，配置为偶校验 */
new_cfg.c_iflag |= INPCK;
break;
default: //默认配置为无校验
new_cfg.c_cflag &= ~PARENB;
new_cfg.c_iflag &= ~INPCK;
printf("default parity: N\n");
break;
}
/* 设置停止位 */
switch (cfg->sbit) {
case 1: //1个停止位
new_cfg.c_cflag &= ~CSTOPB;
break;
case 2: //2个停止位
new_cfg.c_cflag |= CSTOPB;
break;
default: //默认配置为1个停止位
new_cfg.c_cflag &= ~CSTOPB;
printf("default stop bit size: 1\n");
break;
}
/* 将MIN和TIME设置为0 */
new_cfg.c_cc[VTIME] = 0;
new_cfg.c_cc[VMIN] = 0;
/* 清空缓冲区 */
if (0 > tcflush(fd, TCIOFLUSH)) {
fprintf(stderr, "tcflush error: %s\n", strerror(errno));
return -1;
}
/* 写入配置、使配置生效 */
if (0 > tcsetattr(fd, TCSANOW, &new_cfg)) {
fprintf(stderr, "tcsetattr error: %s\n", strerror(errno));
return -1;
}
/* 配置OK 退出 */
return 0;
}
/***
--dev=/dev/ttymxc2
--brate=115200
--dbit=8
--parity=N
--sbit=1
--type=read
***/
/**
** 打印帮助信息
**/
static void show_help(const char *app)
{
printf("Usage: %s [选项]\n"
"\n必选选项:\n"
" --dev=DEVICE 指定串口终端设备名称, 譬如--dev=/dev/ttymxc2\n"
" --type=TYPE 指定操作类型, 读串口还是写串口, 譬如--type=read(read表示读、write表示写、其它值无效)\n"
"\n可选选项:\n"
" --brate=SPEED 指定串口波特率, 譬如--brate=115200\n"
" --dbit=SIZE 指定串口数据位个数, 譬如--dbit=8(可取值为: 5/6/7/8)\n"
" --parity=PARITY 指定串口奇偶校验方式, 譬如--parity=N(N表示无校验、O表示奇校验、E表示偶校验)\n"
" --sbit=SIZE 指定串口停止位个数, 譬如--sbit=1(可取值为: 1/2)\n"
" --help 查看本程序使用帮助信息\n\n", app);
}
/**
** 信号处理函数，当串口有数据可读时，会跳转到该函数执行
**/
static void io_handler(int sig, siginfo_t *info, void *context)
{
unsigned char buf[10] = {0};
int ret;
int n;
if(SIGRTMIN != sig)
return;
/* 判断串口是否有数据可读 */
if (POLL_IN == info->si_code) {
ret = read(fd, buf, 8); //一次最多读8个字节数据
printf("[ ");
for (n = 0; n < ret; n++)
printf("0x%hhx ", buf[n]);
printf("]\n");
}
}
/**
** 异步I/O初始化函数
**/
static void async_io_init(void)
{
struct sigaction sigatn;
int flag;
/* 使能异步I/O */
flag = fcntl(fd, F_GETFL); //使能串口的异步I/O功能
flag |= O_ASYNC;
fcntl(fd, F_SETFL, flag);
/* 设置异步I/O的所有者 */
fcntl(fd, F_SETOWN, getpid());
/* 指定实时信号SIGRTMIN作为异步I/O通知信号 */
fcntl(fd, F_SETSIG, SIGRTMIN);
/* 为实时信号SIGRTMIN注册信号处理函数 */
sigatn.sa_sigaction = io_handler; //当串口有数据可读时，会跳转到io_handler函数
sigatn.sa_flags = SA_SIGINFO;
sigemptyset(&sigatn.sa_mask);
sigaction(SIGRTMIN, &sigatn, NULL);
}
int main(int argc, char *argv[])
{
uart_cfg_t cfg = {0};
char *device = NULL;
int rw_flag = -1;
unsigned char w_buf[10] = {0x11, 0x22, 0x33, 0x44,0x55, 0x66, 0x77, 0x88}; //通过串口发送出去的数据
int n;
/* 解析出参数 */
for (n = 1; n < argc; n++) {
if (!strncmp("--dev=", argv[n], 6))
device = &argv[n][6];
else if (!strncmp("--brate=", argv[n], 8))
cfg.baudrate = atoi(&argv[n][8]);
else if (!strncmp("--dbit=", argv[n], 7))
cfg.dbit = atoi(&argv[n][7]);
else if (!strncmp("--parity=", argv[n], 9))
cfg.parity = argv[n][9];
else if (!strncmp("--sbit=", argv[n], 7))
cfg.sbit = atoi(&argv[n][7]);
else if (!strncmp("--type=", argv[n], 7)) {
if (!strcmp("read", &argv[n][7]))
rw_flag = 0; //读
else if (!strcmp("write", &argv[n][7]))
rw_flag = 1; //写
}
else if (!strcmp("--help", argv[n])) {
show_help(argv[0]); //打印帮助信息
exit(EXIT_SUCCESS);
}
}
if (NULL == device || -1 == rw_flag) {
fprintf(stderr, "Error: the device and read|write type must be set!\n");
show_help(argv[0]);
exit(EXIT_FAILURE);
}
/* 串口初始化 */
if (uart_init(device))
exit(EXIT_FAILURE);
/* 串口配置 */
if (uart_cfg(&cfg)) {
tcsetattr(fd, TCSANOW, &old_cfg); //恢复到之前的配置
close(fd);
exit(EXIT_FAILURE);
}
/* 读|写串口 */
switch (rw_flag) {
case 0: //读串口数据
async_io_init(); //我们使用异步I/O方式读取串口的数据，调用该函数去初始化串口的异步I/O
for ( ; ; )
sleep(1); //进入休眠、等待有数据可读，有数据可读之后就会跳转到io_handler()函数
break;
case 1: //向串口写入数据
for ( ; ; ) { //循环向串口写入数据
write(fd, w_buf, 8); //一次向串口写入8个字节
sleep(1); //间隔1秒钟
}
break;
}
/* 退出 */
tcsetattr(fd, TCSANOW, &old_cfg); //恢复到之前的配置
close(fd);
exit(EXIT_SUCCESS);
}
程序使用正点原子提供。
九、测试
1、数据接收
# ./uart_app --dev=/dev/ttymxc2 --type=read
default baud rate: 115200
default data bit size: 8
default parity: N
default stop bit size: 1
[ 0x11 0x22 0x33 0x44 0x55 0x66 0x77 0x88 ]
[ 0x11 0x22 0x33 0x44 0x55 0x66 0x77 0x88 ]
[ 0x11 0x22 0x33 0x44 0x55 0x66 0x77 0x88 ]
[ 0x11 0x22 0x33 0x44 0x55 0x66 0x77 0x88 ]
[ 0x11 0x22 0x33 0x44 0x55 0x66 0x77 0x88 ]
[ 0x11 0x22 0x33 0x44 0x55 0x66 0x77 0x88 ]
[ 0x11 0x22 0x33 0x44 0x55 0x66 0x77 0x88 ]
[ 0x11 0x22 0x33 0x44 0x55 0x66 0x77 0x88 ]
#
2、数据发送
