【AT-START-F403A测评】+DHT22温湿度检测及显示
<p>除了显示器件的驱动，对各种数字传感器的驱动也是一件十分有益的事情。</p><p>这里就介绍一款单总线数字式温湿度传感器的驱动方法，该器件为DHT22，它较之于DHT11的精度更高，可达小数点后1位。</p>
<p>使用该器件时，其数据引脚与PB11相连接，故有如下的输出高低电平及读取引脚状态的定义引脚：</p>
<p>#define DHT22_D0_H GPIOB->BSRE = GPIO_Pins_15</p>
<p>#define DHT22_D0_L GPIOB->BRE = GPIO_Pins_15</p>
<p>#define DHT22_D0_R GPIO_ReadInputDataBit(GPIOB, GPIO_Pins_15)</p>
<p> </p>
<p>对DHT22初始化的函数为：</p>
<pre>
<code class="language-cpp">uint8_t DHT22_Init(void)
{
GPIO_InitType GPIO_InitStructure;
RCC_APB2PeriphClockCmd(RCC_APB2PERIPH_GPIOB, ENABLE);
GPIO_StructInit(&GPIO_InitStructure);
GPIO_InitStructure.GPIO_Pins = GPIO_Pins_15;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_OUT_PP;
GPIO_InitStructure.GPIO_MaxSpeed = GPIO_MaxSpeed_10MHz;
GPIO_Init(GPIOB, &GPIO_InitStructure);
DHT22_Rst();
return DHT22_Check();
}</code></pre>
<p> </p>
<p>读取DHT22数据的函数为：</p>
<pre>
<code class="language-cpp">uint8_t DHT22_Read_Data(uint8_t *temp,uint8_t *humi)
{
uint8_t buf;
uint8_t i;
DHT22_Rst();
if(DHT22_Check()==0)
{
for(i=0;i<5;i++)
{
buf=DHT22_Read_Byte();
}
if((buf+buf+buf+buf)==buf)
{
*humi=(buf*256+buf)/10;
*temp=(buf*256+buf)/10;
}
}else return 1;
return 0;
}</code></pre>
<p>实现温湿度检测功能程序如下：</p>
<pre>
<code class="language-cpp">if(i==4)
{
showhanzi16h(80,100,5,1);
showhanzi16h(80,84,6,1);
showhanzi16h(180,280,13,0);
showhanzi16h(180,264,14,0);
while(GPIO_ReadInputDataBit(GPIOA, GPIO_Pins_0)==0);
LCD_Clear(WHITE);
show_imageh(10,300,0); //200*200 * 1
BACK_COLOR=WHITE;
POINT_COLOR=RED;
LCD_ShowStringH(60,90,"DHT22 TEST");
senflag=DHT22_Init();
if(senflag) LCD_ShowStringH(80,90,"NO");
else LCD_ShowStringH(80,90,"OK");
while(GPIO_ReadInputDataBit(GPIOA, GPIO_Pins_0)==0)
{
if(!senflag)
{
DHT22_Read_Data(&temperature,&humidity);
LCD_ShowCharh(100,90,'T',1);
LCD_ShowCharh(100,80,'e',1);
LCD_ShowCharh(100,70,'m',1);
LCD_ShowCharh(100,60,'p',1);
LCD_ShowCharh(100,50,':',1);
LCD_ShowCharh(100,40,temperature/10+'0',0);
LCD_ShowCharh(100,30,temperature%10+'0',0);
LCD_ShowCharh(120,90,'H',1);
LCD_ShowCharh(120,80,'u',1);
LCD_ShowCharh(120,70,'m',1);
LCD_ShowCharh(120,60,'i',1);
LCD_ShowCharh(120,50,':',1);
LCD_ShowCharh(120,40,humidity/10+'0',0);
LCD_ShowCharh(120,30,humidity%10+'0',0);
}
Delay_ms(200u);
}
LCD_Clear(WHITE);
AT32_jm();
showhanzi16h(80,100,5,1);
showhanzi16h(80,84,6,1);
showhanzi16h(180,280,13,0);
showhanzi16h(180,264,14,0);
}</code></pre>
<p>该程序的运行效果如图1和图2所示，其中图1为选取环境检测功能，图2位温湿度显示界面。</p>
<p></p>
<p>图1 功能选择</p>
<p></p>
<p>图2 温湿度显示</p>
<p>感谢分享，可以把温度小数点后一位也显示出来哦~这样会更能体现DHT22呢！</p>
<div class="quote">
<blockquote><font size="2"><a href="forum.php?mod=redirect&goto=findpost&pid=3017107&ptid=1144652" target="_blank"><font color="#999999">w494143467 发表于 2020-10-15 21:53</font></a></font> 感谢分享，可以把温度小数点后一位也显示出来哦~这样会更能体现DHT22呢！</blockquote>
</div>
<p>当时图省事，没加否则需再添加一条显示小数的语句。</p>
<p><a href="https://bbs.eeworld.com.cn/thread-1143018-1-1.html" target="_blank">雅特力AT-START-F403A测评汇总</a></p>
<p>汇总贴：<a href="https://bbs.eeworld.com.cn/thread-1143018-1-1.html" target="_blank">https://bbs.eeworld.com.cn/thread-1143018-1-1.html</a></p>
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