DHT11 vs stm32f4

[Burak B]

Merhaba buradaki kodlardan faydalanabilirsiniz sanırım.

[muhittin_kaplan]

#include "stm32f4xx.h"
#include "stm32f4xx_gpio.h"
#include "stm32f4xx_rcc.h"
#include "stm32f4xx_tim.h"
#include "stm32f4xx_usart.h"
#include "misc.h"
#include "stdio.h"
#include "math.h"

GPIO_InitTypeDef  GPIO_InitStructure;
TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;

void DHT11initTIM2(void){
	RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2, ENABLE);
	TIM_TimeBaseStructure.TIM_Period = 84000000-1;//1us
	TIM_TimeBaseStructure.TIM_Prescaler =84;		//1us counter
	TIM_TimeBaseStructure.TIM_ClockDivision = 0;
	TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
	TIM_TimeBaseInit(TIM2, &TIM_TimeBaseStructure);
	TIM_Cmd(TIM2, ENABLE);
}

void DHT11initGPIOasOutput(void){

	 /* GPIOD Periph clock enable */
	RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOD, ENABLE);

	/* Configure PD12, PD13, PD14 and PD15 in output pushpull mode */
	GPIO_InitStructure.GPIO_Pin = GPIO_Pin_1 | GPIO_Pin_12;
	GPIO_InitStructure.GPIO_Mode = GPIO_Mode_OUT;
	GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
	GPIO_InitStructure.GPIO_Speed = GPIO_Speed_100MHz;
	GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL;
	GPIO_Init(GPIOD, &GPIO_InitStructure);

}


void DHT11initGPIOasInput(void){

	 /* GPIOD Periph clock enable */
	RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOD, ENABLE);
	GPIO_InitStructure.GPIO_Pin = GPIO_Pin_1;
	GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN;
	GPIO_Init(GPIOD, &GPIO_InitStructure);

}


void DHT11_delay_us(int us){

	TIM2->CNT = 0;
	while((TIM2->CNT) <= us);
}

float Fahrenheit(u8 celsius)
{
        return 1.8 * celsius + 32;
}

float Kelvin(u8 celsius)
{
        return celsius + 273.15;
}

double dewPointFast(double celsius, double humidity)
{
      double a = 17.271,
             b = 237.7,
             temp ;

      temp = (a * celsius) / (b + celsius) + log(humidity/100);

      return  (b * temp) / (a - temp);;
}




void DHT11Read(u8 *Rh,u8 *RhDec,u8 *Temp,u8 *TempDec, u8 *ChkSum){

			u8 temp;
			u8 j;
			u8 i;
			u8 Value[5]={0x00,0x00,0x00,0x00,0x00};

			DHT11initGPIOasOutput();
			GPIO_ResetBits(GPIOD,GPIO_Pin_1);
			DHT11_delay_us(18000);
			GPIO_SetBits(GPIOD,GPIO_Pin_1);
			DHT11_delay_us(40);
			DHT11initGPIOasInput();

			//80us lik presence										//
			while(!GPIO_ReadInputDataBit(GPIOD,GPIO_Pin_1)){}		//52us 0 level
																	//dht11 response and start to send signal 0-1
			while(GPIO_ReadInputDataBit(GPIOD,GPIO_Pin_1)){}			//80us 1 level
																	//


			for (j = 0; j < 5; ++j) {//5*8 toplam 40 bit Rh,rhdec,temp,tempdec,chksum
				for (i = 0; i < 8; ++i) {

					while(!GPIO_ReadInputDataBit(GPIOD,GPIO_Pin_1)){} //0 olan boş geçiliyor

					TIM_SetCounter(TIM2,0);//Sayıcıyı Sıfırla
					while(GPIO_ReadInputDataBit(GPIOD,GPIO_Pin_1)){}

						temp=TIM_GetCounter(TIM2);//sayıcı değerini al (böylelikle zaman hesaplanıyor)

					if (temp<30) {
						Value[j]=Value[j]<<1;
						}
					else {
						Value[j]=Value[j]<<1;
						Value[j] =Value[j]+1;
						}
				}
			}
    		*Rh=Value[0];
    		*RhDec=Value[1];
    		*Temp=Value[2];
    		*TempDec=Value[3];
    		*ChkSum=Value[4];
}