基于小凌派RK2206开发板：OpenHarmony如何使用IoT接口控制UART外设原创

福州市凌睿智捷电子有限公司

发布于 2025-4-22 14:30

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1、实验简介

本实验将演示如何在小凌派-RK2206开发板上使用IOT库的UART接口，进行UART编程开发。

例程将创建一个任务，通过配置UART引脚，实现UART读写操作。

例程源代码：https://gitee.com/Lockzhiner-Electronics/lockzhiner-rk2206-openharmony3.0lts/tree/master/vendor/lockzhiner/rk2206/samples/b20_iot_uart

2、基础知识

UART在日常设备中非常常见，以下我们将演示IOT库的UART接口如何进行UART口配置，以及UART口读写操作。

2.1、头文件

base/iot_hardware/peripheral/interfaces/kits/iot_uart.h
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2.2、UART设备初始化：IoTUartInit

unsigned int IoTUartInit(unsigned int id, const IotUartAttribute *param);
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描述：

UART设备初始化。

参数：

参数	类型	描述
id	unsigned int	UART ID
param	const IotUartAttribute *	UART配置参数

UART ID配置和IO复用如下表：

串口	id	TX	RX
UART0	EUART0_M0	GPIO0_PB7	GPIO0_PB6
UART0	EUART0_M1	GPIO0_PC7	GPIO0_PC6
UART1	EUART1_M0	GPIO0_PC3	GPIO0_PC2
UART1	EUART1_M1	GPIO0_PA7	GPIO0_PA6
UART2	EUART2_M1	GPIO0_PB3	GPIO0_PB2

返回值：

返回值	描述
IOT_SUCCESS	成功
IOT_FAILURE	失败

实现：

hal_iot_uart.c文件在device/rockchip/rk2206/adapter/hals/iot_hardware/wifiiot_lite目录下。

unsigned int IoTUartInit(unsigned int id, const IotUartAttribute *param)
{
    unsigned int ret = 0;
    UartAttribute *temp_prt = (const UartAttribute *)param;

    if (id >= EUARTDEV_MAX)
    {
        PRINT_ERR("id(%d) >= EUARTDEV_MAX(%d)\n", id, EUARTDEV_MAX);
        return IOT_FAILURE;
    }

    PinctrlSet(m_uart_bus_info[id].uart_bus.rx.gpio, m_uart_bus_info[id].uart_bus.rx.func, m_uart_bus_info[id].uart_bus.rx.type, m_uart_bus_info[id].uart_bus.rx.drv);
    PinctrlSet(m_uart_bus_info[id].uart_bus.tx.gpio, m_uart_bus_info[id].uart_bus.tx.func, m_uart_bus_info[id].uart_bus.tx.type, m_uart_bus_info[id].uart_bus.tx.drv);

    if (param->parity == IOT_UART_PARITY_NONE)
    {
        temp_prt->parity = UART_PARITY_NONE;
    }
    else if (param->parity == IOT_UART_PARITY_EVEN)
    {
        temp_prt->parity = UART_PARITY_EVEN;
    }
    else if (param->parity == IOT_UART_PARITY_ODD)
    {
        temp_prt->parity = UART_PARITY_ODD;
    }

    if (m_uart_bus_info[id].id == 0)
    {
        LzUartDeinit(m_uart_bus_info[id].id);
        uint32_t *pUart0 = (uint32_t *)(0x40070000U);
        HAL_UART_DeInit(pUart0);
    }

    ret = LzUartInit(m_uart_bus_info[id].id, temp_prt);
    if (ret != LZ_HARDWARE_SUCCESS)
    {
        return IOT_FAILURE;
    }

    return IOT_SUCCESS;
}
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2.3、取消初始化UART设备：IoTUartDeinit

unsigned int IoTUartDeinit(unsigned int id);
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描述：

取消初始化UART设备。

参数：

参数	类型	描述
id	unsigned int	UART ID

UART ID配置和IO复用如下表：

串口	id	TX	RX
UART0	EUART0_M0	GPIO0_PB7	GPIO0_PB6
UART0	EUART0_M1	GPIO0_PC7	GPIO0_PC6
UART1	EUART1_M0	GPIO0_PC3	GPIO0_PC2
UART1	EUART1_M1	GPIO0_PA7	GPIO0_PA6
UART2	EUART2_M1	GPIO0_PB3	GPIO0_PB2

返回值：

返回值	描述
IOT_SUCCESS	成功
IOT_FAILURE	失败

实现：

hal_iot_uart.c文件在device/rockchip/rk2206/adapter/hals/iot_hardware/wifiiot_lite目录下。

unsigned int IoTUartDeinit(unsigned int id)
{
    unsigned int ret = 0;

    if (id >= EUARTDEV_MAX)
    {
        PRINT_ERR("id(%d) >= EUARTDEV_MAX(%d)\n", id, EUARTDEV_MAX);
        return IOT_FAILURE;
    }

    ret = LzUartDeinit(m_uart_bus_info[id].id);
    if (ret != LZ_HARDWARE_SUCCESS)
    {
        return IOT_FAILURE;
    }

    return IOT_SUCCESS;
}
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2.4、UART设备读取指定长度的数据：IoTUartRead

int IoTUartRead(unsigned int id, unsigned char *data, unsigned int dataLen);
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描述：

UART设备读取指定长度的数据。

参数：

参数	类型	描述
id	unsigned int	UART ID
data	unsigned char *	数据指针
dataLen	unsigned int	数据长度

UART ID配置和IO复用如下表：

串口	id	TX	RX
UART0	EUART0_M0	GPIO0_PB7	GPIO0_PB6
UART0	EUART0_M1	GPIO0_PC7	GPIO0_PC6
UART1	EUART1_M0	GPIO0_PC3	GPIO0_PC2
UART1	EUART1_M1	GPIO0_PA7	GPIO0_PA6
UART2	EUART2_M1	GPIO0_PB3	GPIO0_PB2

返回值：

返回值	描述
IOT_SUCCESS	成功
IOT_FAILURE	失败

实现：

hal_iot_uart.c文件在device/rockchip/rk2206/adapter/hals/iot_hardware/wifiiot_lite目录下。

int IoTUartRead(unsigned int id, unsigned char *data, unsigned int dataLen)
{
    unsigned int ret = 0;

    if (id >= EUARTDEV_MAX)
    {
        PRINT_ERR("id(%d) >= EUARTDEV_MAX(%d)\n", id, EUARTDEV_MAX);
        return IOT_FAILURE;
    }

    ret = LzUartRead(m_uart_bus_info[id].id, data, dataLen);

    return ret;
}
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2.5、UART设备写指定长度的数据：IoTUartWrite

int IoTUartWrite(unsigned int id, const unsigned char *data, unsigned int dataLen);
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描述：

UART设备读取指定长度的数据。

参数：

参数	类型	描述
id	unsigned int	UART ID
data	const unsigned char *	数据指针
dataLen	unsigned int	数据长度

UART ID配置和IO复用如下表：

串口	id	TX	RX
UART0	EUART0_M0	GPIO0_PB7	GPIO0_PB6
UART0	EUART0_M1	GPIO0_PC7	GPIO0_PC6
UART1	EUART1_M0	GPIO0_PC3	GPIO0_PC2
UART1	EUART1_M1	GPIO0_PA7	GPIO0_PA6
UART2	EUART2_M1	GPIO0_PB3	GPIO0_PB2

返回值：

返回值	描述
IOT_SUCCESS	成功
IOT_FAILURE	失败

实现：

hal_iot_uart.c文件在device/rockchip/rk2206/adapter/hals/iot_hardware/wifiiot_lite目录下。

int IoTUartWrite(unsigned int id, const unsigned char *data, unsigned int dataLen)
{
    unsigned int ret = 0;

    if (id >= EUARTDEV_MAX)
    {
        PRINT_ERR("id(%d) >= EUARTDEV_MAX(%d)\n", id, EUARTDEV_MAX);
        return IOT_FAILURE;
    }

    ret = LzUartWrite(m_uart_bus_info[id].id, data, dataLen);
    if (ret != LZ_HARDWARE_SUCCESS)
    {
        return IOT_FAILURE;
    }

    return IOT_SUCCESS;
}
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3、程序设计

主要代码分析

在uart_example函数中，创建一个任务。

void uart_example()
{
    unsigned int thread_id;
    TSK_INIT_PARAM_S task = {0};
    unsigned int ret      = LOS_OK;

    task.pfnTaskEntry = (TSK_ENTRY_FUNC)uart_thread;
    task.uwStackSize  = 2048;
    task.pcName       = "uart_thread";
    task.usTaskPrio   = 24;
    ret               = LOS_TaskCreate(&thread_id, &task);
    if (ret != LOS_OK) {
        printf("Falied to create uart_thread ret:0x%x\n", ret);
        return;
    }
}
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uart_thread任务中调用IOT库的UART接口配置、读写UART。

void uart_thread()
{
    unsigned int ret;
    IotUartAttribute attr;
    unsigned char str[]                       = "HelloWorld!";
    unsigned char recv_buffer[STRING_MAXSIZE] = {0};
    unsigned int recv_length                  = 0;

    IoTUartDeinit(UART_ID);

    attr.baudRate = 115200;
    attr.dataBits = IOT_UART_DATA_BIT_8;
    attr.pad      = IOT_FLOW_CTRL_NONE;
    attr.parity   = IOT_UART_PARITY_NONE;
    attr.rxBlock  = IOT_UART_BLOCK_STATE_NONE_BLOCK;
    attr.stopBits = IOT_UART_STOP_BIT_1;
    attr.txBlock  = IOT_UART_BLOCK_STATE_NONE_BLOCK;

    /* 初始化串口 */
    ret = IoTUartInit(UART_ID, &attr);
    if (ret != IOT_SUCCESS) {
        printf("%s, %d: IoTUartInit(%d) failed!\n", __FILE__, __LINE__, ret);
        return;
    }
    /* 休眠1秒 */
    LOS_Msleep(1000);

    while (1) {
        printf("%s, %d: uart write and str(%s), len(%d)!\n", __FILE__, __LINE__, str, strlen(str));
        // IoTUartWrite是异步发送，非阻塞发送
        IoTUartWrite(UART_ID, str, strlen(str));
        // 等待发送完毕
        LOS_Msleep(1000);

        recv_length = 0;
        memset(recv_buffer, 0, sizeof(recv_buffer));
        recv_length = IoTUartRead(UART_ID, recv_buffer, sizeof(recv_buffer));
        printf("%s, %d: uart recv and str(%s), len(%d)\n", __FILE__, __LINE__, recv_buffer, recv_length);

        /* 休眠1秒 */
        LOS_Msleep(1000);
    }
}
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4、编译调试

修改 vendor/lockzhiner/rk2206/sample 路径下 BUILD.gn 文件，指定 iot_uart_example 参与编译。

"./b20_iot_uart:iot_uart_example",
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修改 device/lockzhiner/rk2206/sdk_liteos 路径下 Makefile 文件，添加 -liot_uart_example 参与编译。

hardware_LIBS = -lhal_iothardware -lhardware -lshellcmd -liot_uart_example
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5、运行结果

示例代码编译烧录代码后，按下开发板的RESET按键，使用杜邦线连接TX和RX，通过串口助手查看日志，显示如下：

entering kernel init...
hilog will init.
[MAIN:D]Main: LOS_Start ...
Entering scheduler
OHOS # hiview init success.[UART:E]LzUartDeinit: id 0, controller has NOT been initialized
[UART:E]LzUartDeinit: id 0, controller has NOT been initialized
../../../vendor/lockzhiner/rk2206/samples/b20_iot_uart/iot_uart_example.c, 63: uart write and str(HelloWorld!), len(11)!
../../../vendor/lockzhiner/rk2206/samples/b20_iot_uart/iot_uart_example.c, 72: uart recv and str(HelloWorld!), len(11)
../../../vendor/lockzhiner/rk2206/samples/b20_iot_uart/iot_uart_example.c, 63: uart write and str(HelloWorld!), len(11)!
../../../vendor/lockzhiner/rk2206/samples/b20_iot_uart/iot_uart_example.c, 72: uart recv and str(HelloWorld!), len(11)
../../../vendor/lockzhiner/rk2206/samples/b20_iot_uart/iot_uart_example.c, 63: uart write and str(HelloWorld!), len(11)!
../../../vendor/lockzhiner/rk2206/samples/b20_iot_uart/iot_uart_example.c, 72: uart recv and str(HelloWorld!), len(11)
../../../vendor/lockzhiner/rk2206/samples/b20_iot_uart/iot_uart_example.c, 63: uart write and str(HelloWorld!), len(11)!
../../../vendor/lockzhiner/rk2206/samples/b20_iot_uart/iot_uart_example.c, 72: uart recv and str(HelloWorld!), len(11)

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分类

OpenHarmony

标签

openHarmony

51CTO

51CTO博客

51CTO学堂

基于小凌派RK2206开发板：OpenHarmony如何使用IoT接口控制UART外设原创

1、实验简介

2、基础知识

2.1、头文件

2.2、UART设备初始化：IoTUartInit

2.3、取消初始化UART设备：IoTUartDeinit

2.4、UART设备读取指定长度的数据：IoTUartRead

2.5、UART设备写指定长度的数据：IoTUartWrite

3、程序设计

4、编译调试

5、运行结果

目录

订阅鸿蒙技术特刊，精选内容抢先看

51CTO

51CTO博客

51CTO学堂

基于小凌派RK2206开发板：OpenHarmony如何使用IoT接口控制UART外设 原创

1、实验简介

2、基础知识

2.1、头文件

2.2、UART设备初始化：IoTUartInit

2.3、取消初始化UART设备：IoTUartDeinit

2.4、UART设备读取指定长度的数据：IoTUartRead

2.5、UART设备写指定长度的数据：IoTUartWrite

3、程序设计

4、编译调试

5、运行结果

目录

订阅鸿蒙技术特刊，精选内容抢先看

基于小凌派RK2206开发板：OpenHarmony如何使用IoT接口控制UART外设原创