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第一步：創建工程

上篇文章中有具體流程，這里不做過多贅述

第二步：編程

根據官方提供的DHT11使用手冊。流程如下：

DHT11鏈接：https://pan.baidu.com/s/1DxBY9vMtx5BlxtpIx6okKQ?

提取碼：8034

? ? ? ?將GPIO0設為普通IO口，并設置為輸出狀態，拉高主機，拉低主機18-20ms，拉高主機20-40us；設置為輸入狀態，等待從機響應；響應過后判斷輸入的高電平，在高電平段延時40us后仍為高電平則輸入1，為低電平則輸入0。

程序如下：

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DHT11.c

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//初始化GPIO0

void gpio0_init(void)

{

EALLOW;

GpioCtrlRegs.GPAPUD.bit.GPIO0 = 0;

GpioCtrlRegs.GPAMUX1.bit.GPIO0 =0;

GpioCtrlRegs.GPAQSEL1.bit.GPIO0 = 0;

EDIS;

}

//主機輸出設置

void DHT11_Rst(void)

{

uchar i;

EALLOW;

DAT_DIR=1;

EDIS;

// // test

// while(1) {

// DAT= 0;

// DELAY_US(10);

// DAT = 1;

// DELAY_US(10);

// }

DAT= 0;

DELAY_US(300000);

DAT = 1;

DELAY_US(350);

}

（注：程序中的test目的是測試延時函數DELAY_US（）的真實值）

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//等待DHT11的響應

Uint8 Dht11_Check(void){

Uint8 retry=0;

EALLOW;

DAT_DIR=0;

EDIS;

? ? while (DAT&&retry<100){

? ? ? ? retry++;

? ? ? ? DELAY_US(1);

? ? }

? ? if(retry>=100)return 1; else retry=0;

? ? while (!DAT&&retry<100){

? ? ? ? retry++;

? ? ? ? DELAY_US(1);

? ? }

? ? if(retry>=100)return 1;else return 0;

}

?

//初始化DHT11

Uint8 DHT11_Init (void){

DHT11_Rst();

return Dht11_Check();

}

//從DHT11讀取一個位

uchar Dht11_ReadBit(void){

? ? uchar retry=0;

? ? while (DAT&&retry<100){

? ? ? ? ? ?retry++;

? ? ? ? ? ? DELAY_US(1);

? ? ? ? }

? ? ? ?retry=0;

? ? while(!DAT&&retry<100){

? ? ? retry++;

? ? ? DELAY_US(1);

? ? }

? ? DELAY_US(400);

? ? if(DAT)return 1; else return 0;

}

?

//從DHT11讀取一個字節

uchar Dht11_ReadByte(void){

? ? uchar i,dat;

? ? dat=0;

? ? for (i=0;i<8;i++){

? ? ? ? dat<<=1;

? ? ? ? dat|=Dht11_ReadBit();

? ? }

? ? return dat;

}

?

//讀取一次數據

Uint8 DHT11_ReadData(Uint8 *temp,u8 *humi){

uchar buf[5];

uchar i;

DHT11_Rst();

? ? if(Dht11_Check()==0){

? ? ? ? for(i=0;i<5;i++){

? ? ? ? ? ? buf[i]=Dht11_ReadByte();

? ? ? ? }

? ? ? ? if((buf[0]+buf[1]+buf[2]+buf[3])==buf[4]){

? ? ? ? *humi=buf[0];

? ? ? ? *temp=buf[2];

? ? ? ? }

? ? }

}

?

DHT11.h

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#define uchar? ? ? ? ? ? ? ? ? unsigned char

#define DAT_DIR GpioCtrlRegs.GPADIR.bit.GPIO0?

#define DAT GpioDataRegs.GPADAT.bit.GPIO0

?

extern char temp[4];

?

void gpio0_init(void);

void DHT11_Rst(void);

Uint8 Dht11_Check(void);

Uint8 DHT11_Init (void);

uchar Dht11_ReadBit(void);

uchar Dht11_ReadByte(void);

Uint8 DHT11_ReadData(Uint8 *temp,u8 *humi);

?

這里給出OLED屏.h取字模板，OLED模塊例程主頁有，還請自行參考

?

static int Hzk[][32]=

{

{0x10,0x60,0x02,0x8C,0x00,0x00,0xFE,0x92,0x92,0x92,0x92,0x92,0xFE,0x00,0x00,0x00},

{0x04,0x04,0x7E,0x01,0x40,0x7E,0x42,0x42,0x7E,0x42,0x7E,0x42,0x42,0x7E,0x40,0x00},/*"溫",0*/

?

{0x10,0x60,0x02,0x8C,0x00,0xFE,0x92,0x92,0x92,0x92,0x92,0x92,0xFE,0x00,0x00,0x00},

{0x04,0x04,0x7E,0x01,0x44,0x48,0x50,0x7F,0x40,0x40,0x7F,0x50,0x48,0x44,0x40,0x00},/*"濕",1*/

?

{0x00,0x00,0xFC,0x24,0x24,0x24,0xFC,0x25,0x26,0x24,0xFC,0x24,0x24,0x24,0x04,0x00},

{0x40,0x30,0x8F,0x80,0x84,0x4C,0x55,0x25,0x25,0x25,0x55,0x4C,0x80,0x80,0x80,0x00},/*"度",2*/

};

static int F8X16[]=

{

0x00,0xE0,0x10,0x08,0x08,0x10,0xE0,0x00,0x00,0x0F,0x10,0x20,0x20,0x10,0x0F,0x00,/*"0",0*/

0x00,0x00,0x10,0x10,0xF8,0x00,0x00,0x00,0x00,0x00,0x20,0x20,0x3F,0x20,0x20,0x00,/*"1",1*/

0x00,0x70,0x08,0x08,0x08,0x08,0xF0,0x00,0x00,0x30,0x28,0x24,0x22,0x21,0x30,0x00,/*"2",2*/

0x00,0x30,0x08,0x08,0x08,0x88,0x70,0x00,0x00,0x18,0x20,0x21,0x21,0x22,0x1C,0x00,/*"3",3*/

0x00,0x00,0x80,0x40,0x30,0xF8,0x00,0x00,0x00,0x06,0x05,0x24,0x24,0x3F,0x24,0x24,/*"4",4*/

0x00,0xF8,0x88,0x88,0x88,0x08,0x08,0x00,0x00,0x19,0x20,0x20,0x20,0x11,0x0E,0x00,/*"5",5*/

0x00,0xE0,0x10,0x88,0x88,0x90,0x00,0x00,0x00,0x0F,0x11,0x20,0x20,0x20,0x1F,0x00,/*"6",6*/

0x00,0x18,0x08,0x08,0x88,0x68,0x18,0x00,0x00,0x00,0x00,0x3E,0x01,0x00,0x00,0x00,/*"7",7*/

0x00,0x70,0x88,0x08,0x08,0x88,0x70,0x00,0x00,0x1C,0x22,0x21,0x21,0x22,0x1C,0x00,/*"8",8*/

0x00,0xF0,0x08,0x08,0x08,0x10,0xE0,0x00,0x00,0x01,0x12,0x22,0x22,0x11,0x0F,0x00,/*"9",9*/

0xC0,0x30,0x08,0x08,0x08,0x08,0x38,0x00,0x07,0x18,0x20,0x20,0x20,0x10,0x08,0x00,/*"C",10*/

0xF0,0x08,0xF0,0x80,0x60,0x18,0x00,0x00,0x00,0x31,0x0C,0x03,0x1E,0x21,0x1E,0x00,/*"%",11*/

0x00,0x00,0x04,0x02,0x02,0x04,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,/*"^",12*/

0x08,0xF8,0x88,0x88,0x88,0x88,0x70,0x00,0x20,0x3F,0x20,0x00,0x03,0x0C,0x30,0x20,/*"R",13*/

0x08,0xF8,0x08,0x00,0x00,0x08,0xF8,0x08,0x20,0x3F,0x21,0x01,0x01,0x21,0x3F,0x20,/*"H",14*/

};

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main.c

?

void delay();

Uint8 temperature;

Uint8 humidity;

void main(void)

{

InitSysCtrl();

DINT;

InitPieCtrl();

IER_DISABLE(0xFFFF);

IFR_DISABLE(0xFFFF);

InitPieVectTable();

InitCpuTimers();

? ? gpio0_init();

? ? I2C_GPIO_Config_OLED();

? ? OLED_Init();

OLED_Clear();

OLED_ShowCHinese(0,0,0);

OLED_ShowCHinese(16,0,2);

OLED_ShowCHinese(0,4,1);

OLED_ShowCHinese(16,4,2);

? ? while(1)

? ? {

? ? ? ? ? DHT11_ReadData(&temperature,&humidity);

? ? ? OLED_ShowNum(40,0,temperature,2,16);

? ? ? OLED_ShowNum(40,4,humidity,2,16);

OLED_ShowChar(56,0,12,16);

OLED_ShowChar(64,0,10,16);

OLED_ShowChar(56,4,11,16);

OLED_ShowChar(64,4,13,16);

OLED_ShowChar(72,4,14,16);

? ? ? delay();

? ?}

}

void delay(void)

{

for(int i=0;i<50000;i++);

}

第三步：調試與顯示溫濕度

調試無錯后，全速狀態下顯示的溫濕度值會因環境溫濕度的變化而變化，顯示效果如下：

特別鳴謝 原創作者 博主「晟逸軒」