HarmonyOS小熊派 | HarmonyOS基础外设开发--UART数据读写

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Yuchuan 发表于 2021/07/08 20:53:45 2021/07/08
【摘要】 基础外设开发--UART数据读写

BearPi-HM_Nano开发板基础外设开发——UART数据读写

本示例将演示如何在BearPi-HM_Nano开发板上使用UART进行数据的收发

BearPi-HM_Nano

UART API分析

本示例主要使用了以下API完成UART数据读写

1、IoTUartInit()

/**
 * @brief Configures a UART device with the port number specified by <b>id</b>
 * based on the basic and extended attributes.
 *
 *
 *
 * @param id Indicates the port number of the UART device.
 * @param param Indicates the pointer to the UART attributes.
 * @return Returns {@link IOT_SUCCESS} if the UART device is configured successfully;
 * returns {@link IOT_FAILURE} otherwise. For details about other return values, see the chip description.
 * @since 2.2
 * @version 2.2
 */
unsigned int IoTUartInit(unsigned int id, const IotUartAttribute *param);

描述：

配置一个UART设备。 参数：

名字 描述
id UART端口号.
param 表示基本UART属性

2、IoTUartWrite()

/**
 * @brief Writes a specified length of data to a UART device with the port number specified by <b>id</b>.
 *
 *
 *
 * @param id Indicates the port number of the UART device.
 * @param data Indicates the pointer to the start address of the data to write.
 * @param dataLen Indicates the number of bytes to write.
 * @return Returns the number of bytes written if the operation is successful; returns <b>-1</b> otherwise.
 * @since 2.2
 * @version 2.2
 */
int IoTUartWrite(unsigned int id, const unsigned char *data, unsigned int dataLen);

描述： 将数据写入UART设备

参数：

名字 描述
id UART端口号.
data 表示指向要写入数据的起始地址的指针
dataLen 表示读取数据的长度

3、IoTUartRead()

/**
 * @brief Reads a specified length of data from a UART device with the port number specified by <b>id</b>.
 *
 *
 *
 * @param id Indicates the port number of the UART device.
 * @param data Indicates the pointer to the start address of the data to read.
 * @param dataLen Indicates the number of bytes to read.
 * @return Returns the number of bytes read if the operation is successful; returns <b>-1</b> otherwise.
 * @since 2.2
 * @version 2.2
 */
int IoTUartRead(unsigned int id, unsigned char *data, unsigned int dataLen);

描述：

从UART设备读取数据。

参数：

名字 描述
id UART端口号.
data 表示指向要读取数据的起始地址的指针
dataLen 表示读取数据的长度

硬件设计

本案例将用 BearPi-HM_Nano 开发板 E53 接口的 UART 作为测试，如原理图所示第 18 和 19 脚分别为 TXD 和 RXD ，连接了主控芯片的 GPIO_6 和 GPIO_5 ，所以在编写软件的时候需要将 GPIO_6 和 GPIO_5 分别复用为 TXD 和 RXD 。

软件设计

主要代码分析

这部分代码为UART初始化的代码，首先要在 uart_attr 结构体这配置波特率、数据位、停止位、奇偶检验位，然后通过 IoTUartInit() 函数对串口1进行配置。

这部分的代码主要实现通过 IoTUartWrite() 函数在串口1发送一串数据，然后通过 IoTUartRead() 函数将数据都回来，并通过 debug 串口打印出来。

yuchuan_basic_uart.c

#include <stdio.h>
#include <string.h>
#include <unistd.h>

#include "ohos_init.h"
#include "cmsis_os2.h"
#include "iot_uart.h"
#include "iot_errno.h"

#define THREAD_CB_MEM_SIZE 0U
#define THREAD_STACK_MEM_SIZE 1024 * 4
#define THREAD_PRIORITY 25
#define IOT_UART_IDX_1 1
#define UART_BUFF_SIZE 1000

static const char *data = "Yuchuan Huaying HarmonyOS Hello!!!\n";

static void yuchuanUartTask(void *argument)
{
    (void)argument;
    uint32_t ret;
    uint8_t uart_buff[UART_BUFF_SIZE] = {0};
    uint8_t *uart_buff_p = uart_buff;
    int i = 0;

    IotUartAttribute uart_attr = {
        .baudRate = 9600,
        .dataBits = 8,
        .stopBits =1,
        .parity = 0,
    };

    //初始化UART driver
    ret = IoTUartInit(IOT_UART_IDX_1,&uart_attr);
    if (ret != IOT_SUCCESS)
    {
        /* code */
        printf("Init Uart Falied Error No : %d\n",ret);
        return;
    }

    printf("Uart Test Start!!!\n");

    while (1)
    {
        i++;
        if (i > 5)
        {
            /* code */
            return;
        }
        
        /* code */
        printf("====================================================\r\n");
        printf("*************Yuchuan UART_Example Task**************\r\n");
        printf("====================================================\r\n");

        //通过串口1发送数据
        IoTUartWrite(IOT_UART_IDX_1,(unsigned char*)data,strlen(data));

        //通过串口1接收数据
        IoTUartRead(IOT_UART_IDX_1,uart_buff_p,UART_BUFF_SIZE);
        printf("Yuchuan Read Uart Data : %s %d\n",uart_buff_p,i);
        usleep(3000000);
    }
    i = 0; 
}

static void yuchuanBasicUARTEntry(void)
{
    osThreadAttr_t threadAttr;

    threadAttr.attr_bits = 0U;
    threadAttr.cb_mem = NULL;
    threadAttr.cb_size = THREAD_CB_MEM_SIZE;
    threadAttr.stack_mem = NULL;
    threadAttr.stack_size = THREAD_STACK_MEM_SIZE;
    threadAttr.priority = THREAD_PRIORITY;

    threadAttr.name = "BasicUARTThread";
    if (osThreadNew((osThreadFunc_t)yuchuanUartTask, NULL, &threadAttr) == NULL)
    {
        /* code */
        printf("Falied to Create Basic UART Task!!!\n");
    }
    
}

APP_FEATURE_INIT(yuchuanBasicUARTEntry);

编译调试

//applications/sample/BearPi/BearPi-HM_Nano/sample/B6_YuchuanBasicUART

static_library("YuchuanBasicUART"){
    sources = [
        "yuchuan_basic_uart.c",
    ]

    include_dirs = [
        "//utils/native/lite/include",
        "//kernel/liteos_m/kal/cmsis",
        "//base/iot_hardware/peripheral/interfaces/kits",
    ]
}

修改 BUILD.gn 文件

修改 applications\BearPi\BearPi-HM_Nano\sample 路径下 BUILD.gn 文件，指定 YuchuanBasicUART 参与编译。

# Copyright (c) 2020 Nanjing Xiaoxiongpai Intelligent Technology Co., Ltd.
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

import("//build/lite/config/component/lite_component.gni")

lite_component("sample") {
    features = [
        #"A1_kernal_thread:thread_example",
        #"A2_kernel_timer:timer_example",
        #"A3_kernel_event:event_example",
        #"A4_kernel_mutex:mutex_example",
        #"A5_kernel_semaphore:semaphore_example",
        #"A6_kernel_message:message_example",

        #"B1_basic_led_blink:led_example",
        #"B2_basic_button:button_example",
        #"B3_basic_pwm_led:pwm_example",
        #"B4_basic_adc:adc_example", 
        #"B5_basic_i2c_nfc:i2c_example",
        #"B6_basic_uart:uart_example",
        
        #"C1_e53_sf1_mq2:e53_sf1_example",
        #"C2_e53_ia1_temp_humi_pls:e53_ia1_example",
        #"C3_e53_sc1_pls:e53_sc1_example",
        #"C4_e53_sc2_axis:e53_sc2_example",
        #"C5_e53_is1_infrared:e53_is1_example",

        #"D1_iot_wifi_ap:wifi_ap",
        #"D2_iot_wifi_sta_connect:wifi_sta_connect",        
        #"D3_iot_udp_client:udp_client",
        #"D4_iot_tcp_server:tcp_server",
        #"D5_iot_mqtt:iot_mqtt",        
        #"D6_iot_cloud_oc:oc_mqtt",
        #"D7_iot_cloud_onenet:onenet_mqtt",
        #"D8_iot_cloud_oc_smoke:cloud_oc_smoke",
        #"D9_iot_cloud_oc_light:cloud_oc_light",
        #"D10_iot_cloud_oc_manhole_cover:cloud_oc_manhole_cover",
        #"D11_iot_cloud_oc_infrared:cloud_oc_infrared",
        #"D12_iot_cloud_oc_agriculture:cloud_oc_agriculture",
        #"D13_iot_cloud_oc_gps:cloud_oc_gps",
        #"A1_YuchuanThread:yuchuanThread",
        #"A2_YuchuanTimer:yuchuanTimer",
        #"A4_YuchuanMutex:yuchuanMutex",
        #"A5_YuchuanSemaphore:yuchuanSemaphore",
        #"A3_YuchuanEvent:yuchuanEvent",
        #"A6_YuchuanMessage:yuchuanMessageQueue",
        #"B3_YuchuanBasicPWM:yuchuanPWM",
        #"B4_YuchuanBasicADC:yuchuanBasicADC",
        #"B5_YuchuanNFCI2C:yuchuanNFCI2C",
        "B6_YuchuanBasicUART:YuchuanBasicUART",
    ]
}

运行结果

示例代码编译烧录代码后，按下开发板的RESET按键， 未将开发板上E53接口的UART_TX和UART_RX用跳线短接 通过串口助手查看日志，串口1实现自发自收。

ready to OS start
sdk ver:Hi3861V100R001C00SPC025 2020-09-03 18:10:00
FileSystem mount ok.
wifi init success!

hiview init success.Uart Test Start!!!
====================================================
*************Yuchuan UART_Example Task**************
====================================================
Yuchuan Read Uart Data :  1
00 00:00:00 0 132 D 0/HIVIEW: log limit init success.
00 00:00:00 0 132 I 1/SAMGR: Bootstrap core services(count:3).
00 00:00:00 0 132 I 1/SAMGR: Init service:0x4b0388 TaskPool:0xe4b3c
00 00:00:00 0 132 I 1/SAMGR: Init service:0x4b0394 TaskPool:0xe4b5c
00 00:00:00 0 132 I 1/SAMGR: Init service:0x4b0860 TaskPool:0xe4b7c
00 00:00:00 0 164 I 1/SAMGR: Init service 0x4b0394 <time: 0ms> success!
00 00:00:00 0 64 I 1/SAMGR: Init service 0x4b0388 <time: 10ms> success!
00 00:00:00 0 8 I 1/SAMGR: Init service 0x4b0860 <time: 10ms> success!
00 00:00:00 0 8 I 1/SAMGR: Initialized all core system services!
00 00:00:00 0 64 I 1/SAMGR: Bootstrap system and application services(count:0).
00 00:00:00 0 64 I 1/SAMGR: Initialized all system and application services!
00 00:00:00 0 64 I 1/SAMGR: Bootstrap dynamic registered services(count:0).
====================================================
*************Yuchuan UART_Example Task**************
====================================================
Yuchuan Read Uart Data :  2
====================================================
*************Yuchuan UART_Example Task**************
====================================================
Yuchuan Read Uart Data :  3
====================================================
*************Yuchuan UART_Example Task**************
====================================================
Yuchuan Read Uart Data :  4
====================================================
*************Yuchuan UART_Example Task**************
====================================================
Yuchuan Read Uart Data :  5

示例代码编译烧录代码后，按下开发板的RESET按键， 将开发板上E53接口的UART_TX和UART_RX用跳线短接 通过串口助手查看日志，串口1实现自发自收。

ready to OS start
sdk ver:Hi3861V100R001C00SPC025 2020-09-03 18:10:00
formatting spiffs...
FileSystem mount ok.
wifi init success!

hiview init success.Uart Test Start!!!
====================================================
*************Yuchuan UART_Example Task**************
====================================================
Yuchuan Read Uart Data :  1
00 00:00:00 0 132 D 0/HIVIEW: log limit init success.
00 00:00:00 0 132 I 1/SAMGR: Bootstrap core services(count:3).
00 00:00:00 0 132 I 1/SAMGR: Init service:0x4b0388 TaskPool:0xe4b3c
00 00:00:00 0 132 I 1/SAMGR: Init service:0x4b0394 TaskPool:0xe4b5c
00 00:00:00 0 132 I 1/SAMGR: Init service:0x4b0860 TaskPool:0xe4b7c
00 00:00:00 0 164 I 1/SAMGR: Init service 0x4b0394 <time: 10ms> success!
00 00:00:00 0 64 I 1/SAMGR: Init service 0x4b0388 <time: 10ms> success!
00 00:00:00 0 8 I 1/SAMGR: Init service 0x4b0860 <time: 10ms> success!
00 00:00:00 0 8 I 1/SAMGR: Initialized all core system services!
00 00:00:00 0 64 I 1/SAMGR: Bootstrap system and application services(count:0).
00 00:00:00 0 64 I 1/SAMGR: Initialized all system and application services!
00 00:00:00 0 64 I 1/SAMGR: Bootstrap dynamic registered services(count:0).
====================================================
*************Yuchuan UART_Example Task**************
====================================================
Yuchuan Read Uart Data : Yuchuan Huaying HarmonyOS Hello!!!
 2
====================================================
*************Yuchuan UART_Example Task**************
====================================================
Yuchuan Read Uart Data : Yuchuan Huaying HarmonyOS Hello!!!
 3
====================================================
*************Yuchuan UART_Example Task**************
====================================================
Yuchuan Read Uart Data : Yuchuan Huaying HarmonyOS Hello!!!
 4
====================================================
*************Yuchuan UART_Example Task**************
====================================================
Yuchuan Read Uart Data : Yuchuan Huaying HarmonyOS Hello!!!
 5
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