【HarmonyOS HiSpark Wi-Fi IoT 套件试用连连载】四、环境监测板的使用 - HarmonyOS技术社区 - 电子技术论坛

李元江

2020-12-21 23:13:43

今天来写一篇关于使用环境监测板的帖子。主要完成温湿度传感器数据采集和烟雾传感器的数据采集，然后把采集到的数据打印输出。

一、硬件介绍

通过查看环境监测板的原理图，发现该板子主要有三个板子资源：AHT20温湿度传感器、MQ-2烟雾传感器、蜂鸣器。

它们使用主控的GPIO口分别为：AHT20温湿度传感器

SDA --》 GPIO13 可复用为I2C0_SDA

SCL --》 GPIO14 可复用为I2C0_SCL

MQ-2烟雾传感器

ADC --》 GPIO11

可复用为ADC5

蜂鸣器BEEP --》

GPIO9 可复用为PWM0_OUT

二、软件设计
1、新建文件

在wifi-iot/app目录下，新建EM文件夹，存放与环境监测板相关的代码。

在EM文件夹分别新建aht20.c、aht20.h、envrionment_demo.c和BUILD.gn文件。

上面c文件和h文件我是从许思维老师demo工程中移植过来的,然后进行了一些修改。

2、aht20.c

该c文件主要存放与aht20传感器操作相关的代码

/*
* Copyright (c) 2020, HiHope Community.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* 3. Neither the name of the copyright holder nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "aht20.h"
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include "wifiiot_i2c.h"
#include "wifiiot_errno.h"
#define AHT20_I2C_IDX WIFI_IOT_I2C_IDX_0
#define AHT20_STARTUP_TIME 20*1000 // 上电启动时间
#define AHT20_CALIBRATION_TIME 40*1000 // 初始化（校准）时间
#define AHT20_MEASURE_TIME 75*1000 // 测量时间
#define AHT20_DEVICE_ADDR 0x38
#define AHT20_READ_ADDR ((0x38<<1)|0x1)
#define AHT20_WRITE_ADDR ((0x38<<1)|0x0)
#define AHT20_CMD_CALIBRATION 0xBE // 初始化（校准）命令
#define AHT20_CMD_CALIBRATION_ARG0 0x08
#define AHT20_CMD_CALIBRATION_ARG1 0x00
/**
* 传感器在采集时需要时间,主机发出测量指令（0xAC）后，延时75毫秒以上再读取转换后的数据并判断返回的状态位是否正常。
* 若状态比特位[Bit7]为0代表数据可正常读取，为1时传感器为忙状态，主机需要等待数据处理完成。
**/
#define AHT20_CMD_TRIGGER 0xAC // 触发测量命令
#define AHT20_CMD_TRIGGER_ARG0 0x33
#define AHT20_CMD_TRIGGER_ARG1 0x00
// 用于在无需关闭和再次打开电源的情况下，重新启动传感器系统，软复位所需时间不超过20 毫秒
#define AHT20_CMD_RESET 0xBA // 软复位命令
#define AHT20_CMD_STATUS 0x71 // 获取状态命令
/**
* STATUS 命令回复：
* 1. 初始化后触发测量之前，STATUS 只回复 1B 状态值；
* 2. 触发测量之后，STATUS 回复6B： 1B 状态值 + 2B 湿度 + 4b湿度 + 4b温度 + 2B 温度
* RH = Srh / 2^20 * 100%
* T = St / 2^20 * 200 - 50
**/
#define AHT20_STATUS_BUSY_SHIFT 7 // bit[7] Busy indication
#define AHT20_STATUS_BUSY_MASK (0x1<<AHT20_STATUS_BUSY_SHIFT)
#define AHT20_STATUS_BUSY(status) ((status & AHT20_STATUS_BUSY_MASK) >> AHT20_STATUS_BUSY_SHIFT)
#define AHT20_STATUS_MODE_SHIFT 5 // bit[6:5] Mode Status
#define AHT20_STATUS_MODE_MASK (0x3<<AHT20_STATUS_MODE_SHIFT)
#define AHT20_STATUS_MODE(status) ((status & AHT20_STATUS_MODE_MASK) >> AHT20_STATUS_MODE_SHIFT)
// bit[4] Reserved
#define AHT20_STATUS_CALI_SHIFT 3 // bit[3] CAL Enable
#define AHT20_STATUS_CALI_MASK (0x1<<AHT20_STATUS_CALI_SHIFT)
#define AHT20_STATUS_CALI(status) ((status & AHT20_STATUS_CALI_MASK) >> AHT20_STATUS_CALI_SHIFT)
// bit[2:0] Reserved
#define AHT20_STATUS_RESPONSE_MAX 6
#define AHT20_RESLUTION (1<<20) // 2^20
#define AHT20_MAX_RETRY 10
static uint32_t AHT20_Read(uint8_t* buffer, uint32_t buffLen)
{
WifiIotI2cData data = { 0 };
data.receiveBuf = buffer;
data.receiveLen = buffLen;
uint32_t retval = I2cRead(AHT20_I2C_IDX, AHT20_READ_ADDR, &data);
if (retval != WIFI_IOT_SUCCESS) {
printf("I2cRead() failed, %0X!
", retval);
return retval;
}
return WIFI_IOT_SUCCESS;
}
static uint32_t AHT20_Write(uint8_t* buffer, uint32_t buffLen)
{
WifiIotI2cData data = { 0 };
data.sendBuf = buffer;
data.sendLen = buffLen;
uint32_t retval = I2cWrite(AHT20_I2C_IDX, AHT20_WRITE_ADDR, &data);
if (retval != WIFI_IOT_SUCCESS) {
printf("I2cWrite(%02X) failed, %0X!
", buffer[0], retval);
return retval;
}
return WIFI_IOT_SUCCESS;
}
// 发送获取状态命令
static uint32_t AHT20_StatusCommand(void)
{
uint8_t statusCmd[] = { AHT20_CMD_STATUS };
return AHT20_Write(statusCmd, sizeof(statusCmd));
}
// 发送软复位命令
static uint32_t AHT20_ResetCommand(void)
{
uint8_t resetCmd[] = {AHT20_CMD_RESET};
return AHT20_Write(resetCmd, sizeof(resetCmd));
}
// 发送初始化校准命令
static uint32_t AHT20_CalibrateCommand(void)
{
uint8_t clibrateCmd[] = {AHT20_CMD_CALIBRATION, AHT20_CMD_CALIBRATION_ARG0, AHT20_CMD_CALIBRATION_ARG1};
return AHT20_Write(clibrateCmd, sizeof(clibrateCmd));
}
// 读取温湿度值之前，首先要看状态字的校准使能位Bit[3]是否为 1(通过发送0x71可以获取一个字节的状态字)，
// 如果不为1，要发送0xBE命令(初始化)，此命令参数有两个字节，第一个字节为0x08，第二个字节为0x00。
uint32_t AHT20_Calibrate(void)
{
uint32_t retval = 0;
uint8_t buffer[AHT20_STATUS_RESPONSE_MAX] = { AHT20_CMD_STATUS };
memset(&buffer, 0x0, sizeof(buffer));
retval = AHT20_StatusCommand();
if (retval != WIFI_IOT_SUCCESS) {
return retval;
}
retval = AHT20_Read(buffer, sizeof(buffer));
if (retval != WIFI_IOT_SUCCESS) {
return retval;
}
if (AHT20_STATUS_BUSY(buffer[0]) || !AHT20_STATUS_CALI(buffer[0])) {
retval = AHT20_ResetCommand();
if (retval != WIFI_IOT_SUCCESS) {
return retval;
}
usleep(AHT20_STARTUP_TIME);
retval = AHT20_CalibrateCommand();
usleep(AHT20_CALIBRATION_TIME);
return retval;
}
return WIFI_IOT_SUCCESS;
}
// 发送触发测量命令，开始测量
uint32_t AHT20_StartMeasure(void)
{
uint8_t triggerCmd[] = {AHT20_CMD_TRIGGER, AHT20_CMD_TRIGGER_ARG0, AHT20_CMD_TRIGGER_ARG1};
return AHT20_Write(triggerCmd, sizeof(triggerCmd));
}
// 接收测量结果，拼接转换为标准值
uint32_t AHT20_GetMeasureResult(float* temp, float* humi)
{
uint32_t retval = 0, i = 0;
if (temp == NULL || humi == NULL) {
return WIFI_IOT_FAILURE;
}
uint8_t buffer[AHT20_STATUS_RESPONSE_MAX] = { 0 };
memset(&buffer, 0x0, sizeof(buffer));
retval = AHT20_Read(buffer, sizeof(buffer)); // recv status command result
if (retval != WIFI_IOT_SUCCESS) {
return retval;
}
for (i = 0; AHT20_STATUS_BUSY(buffer[0]) && i < AHT20_MAX_RETRY; i++) {
// printf("AHT20 device busy, retry %d/%d!
", i, AHT20_MAX_RETRY);
usleep(AHT20_MEASURE_TIME);
retval = AHT20_Read(buffer, sizeof(buffer)); // recv status command result
if (retval != WIFI_IOT_SUCCESS) {
return retval;
}
}
if (i >= AHT20_MAX_RETRY) {
printf("AHT20 device always busy!
");
return WIFI_IOT_FAILURE;
}
uint32_t humiRaw = buffer[1];
humiRaw = (humiRaw << 8) | buffer[2];
humiRaw = (humiRaw << 4) | ((buffer[3] & 0xF0) >> 4);
*humi = humiRaw / (float)AHT20_RESLUTION * 100;
uint32_t tempRaw = buffer[3] & 0x0F;
tempRaw = (tempRaw << 8) | buffer[4];
tempRaw = (tempRaw << 8) | buffer[5];
*temp = tempRaw / (float)AHT20_RESLUTION * 200 - 50;
// printf("humi = %05X, %f, temp= %05X, %f
", humiRaw, *humi, tempRaw, *temp);
return WIFI_IOT_SUCCESS;
}
3.aht20.h
/*
* Copyright (c) 2020, HiHope Community.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* 3. Neither the name of the copyright holder nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#ifndef AHT20_H
#define AHT20_H
#include <stdint.h>
uint32_t AHT20_Calibrate(void);
uint32_t AHT20_StartMeasure(void);
uint32_t AHT20_GetMeasureResult(float* temp, float* humi);
#endif // AHT20_H

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4、envrionment_demo.c

该c文件是在许思维老师例程代码基础上进行修改，需要I2C功能，需要把IO配置为I2C功能，且前面要加上 GpioInit()函数，才能成功配置IO。

/*
* Copyright (c) 2020, HiHope Community.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* 3. Neither the name of the copyright holder nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include <stdio.h>
#include <stdint.h>
#include <string.h>
#include <unistd.h>
#include "ohos_init.h"
#include "cmsis_os2.h"
#include "wifiiot_i2c.h"
#include "wifiiot_gpio.h"
#include "wifiiot_gpio_ex.h"
#include "wifiiot_pwm.h"
#include "wifiiot_adc.h"
#include "wifiiot_errno.h"
#include "aht20.h"
//#include "oled_ssd1306.h"
#ifndef ARRAY_SIZE
#define ARRAY_SIZE(a) sizeof(a)/sizeof(a[0])
#endif
#define MS_PER_S 1000
#define BEEP_TIMES 3
#define BEEP_DURATION 100
#define BEEP_PWM_DUTY 30000
#define BEEP_PWM_FREQ 60000
#define BEEP_PIN_NAME WIFI_IOT_IO_NAME_GPIO_9
#define BEEP_PIN_FUNCTION WIFI_IOT_IO_FUNC_GPIO_9_PWM0_OUT
#define GAS_SENSOR_CHAN_NAME WIFI_IOT_ADC_CHANNEL_5
// #define GAS_SENSOR_PIN_NAME WIFI_IOT_IO_NAME_GPIO_11
#define AHT20_BAUDRATE 400*1000
#define AHT20_I2C_IDX WIFI_IOT_I2C_IDX_0
#define ADC_RESOLUTION 2048
static float ConvertToVoltage(unsigned short data)
{
return (float)data * 1.8 * 4 / 4096;
}
static void EnvironmentTask(void *arg)
{
(void)arg;
uint32_t retval = 0;
float humidity = 0.0f;
float temperature = 0.0f;
float gasSensorResistance = 0.0f;
/*I2C IO口初始化化*/
GpioInit();
IoSetFunc(WIFI_IOT_IO_NAME_GPIO_13, WIFI_IOT_IO_FUNC_GPIO_13_I2C0_SDA);
IoSetFunc(WIFI_IOT_IO_NAME_GPIO_14, WIFI_IOT_IO_FUNC_GPIO_14_I2C0_SCL);
I2cInit(AHT20_I2C_IDX, AHT20_BAUDRATE);
while (WIFI_IOT_SUCCESS != AHT20_Calibrate()) {
printf("AHT20 sensor init failed!
");
usleep(1000);
}
while(1) {
retval = AHT20_StartMeasure();
if (retval != WIFI_IOT_SUCCESS) {
printf("trigger measure failed!
");
}
retval = AHT20_GetMeasureResult(&temperature, &humidity);
if (retval != WIFI_IOT_SUCCESS) {
printf("get humidity data failed!
");
}
unsigned short data = 0;
if (AdcRead(GAS_SENSOR_CHAN_NAME, &data, WIFI_IOT_ADC_EQU_MODEL_4, WIFI_IOT_ADC_CUR_BAIS_DEFAULT, 0)
== WIFI_IOT_SUCCESS) {
float Vx = ConvertToVoltage(data);
gasSensorResistance = 5 / Vx - 1;
}
printf("temp: %.2f
", temperature);
printf("humi: %.2f
", humidity);
printf("gas: %.2f kom
", gasSensorResistance);
sleep(1);
}
}
static void EnvironmentDemo(void)
{
osThreadAttr_t attr;
attr.name = "EnvironmentTask";
attr.attr_bits = 0U;
attr.cb_mem = NULL;
attr.cb_size = 0U;
attr.stack_mem = NULL;
attr.stack_size = 4096;
attr.priority = osPriorityNormal;
if (osThreadNew(EnvironmentTask, NULL, &attr) == NULL) {
printf("[EnvironmentDemo] Falied to create EnvironmentTask!
");
}
}
APP_FEATURE_INIT(EnvironmentDemo);

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5、BUILD.gn

BUILD.gn内容为

#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions are met:
#
# 1. Redistributions of source code must retain the above copyright notice, this
# list of conditions and the following disclaimer.
#
# 2. Redistributions in binary form must reproduce the above copyright notice,
# this list of conditions and the following disclaimer in the documentation
# and/or other materials provided with the distribution.
#
# 3. Neither the name of the copyright holder nor the names of its
# contributors may be used to endorse or promote products derived from
# this software without specific prior written permission.
#
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
# AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
# DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
# SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
# CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
# OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
static_library("em_example") {
sources = [
"envrionment_demo.c",
"aht20.c"
]
include_dirs = [
"//utils/native/lite/include",
"//kernel/liteos_m/components/cmsis/2.0",
"//base/iot_hardware/interfaces/kits/wifiiot_lite",
]
}

复制代码

这样还不行，还要修改app文件夹下的BUILD.gn。在features下增加"EM:em_example"，

lite_component("app") {
features = [
"startup",
"SSL:ssl_example",
"EM:em_example",
"OLED:oled_example"
]
}

复制代码

6、增加I2C功能

在默认情况下，hi3861_sdk中，I2C在CONFIG选项里没有打开，所以I2C无法进行使用我们需要修改vendorhisihi3861hi3861uildconfigusr_config.mk文件中的CONFIG_I2C_SUPPORT行：# CONFIG_I2C_SUPPORT is not set修改为CONFIG_I2C_SUPPORT=y

三、编译烧录

烧录成功后，使用串口组手，查看到已经可以打印输出数据。

四、总结

前一段时间太忙，确实落下很多进度，之后要加快学习速度了。再一次感谢许思维老师，查看许思维老师的例程代码，确实帮助了自己很多。明天我将写一篇关于OLED12864的帖子，主要功能为显示时钟、温湿度，总之要加快进度啦。

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[文章]【HarmonyOS HiSpark Wi-Fi IoT 套件试用连连载】四、环境监测板的使用

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