temperature LCD and DHT11

 Code for  temperature LCD and DHT11

/*

 * temperature LCD and DHT11.c

 *

 * Created: 7/16/2020 7:41:41 PM

 * Author : Daniel F Diaz Bayona

 */ 

#include <avr/io.h>

#include <stdlib.h>

#include <stdio.h>

#include "LCD16x2_4bit.h"

#define DHT11_PIN 8

uint8_t c=0,I_RH,D_RH,I_Temp,D_Temp,CheckSum;

//here we will set the pin to low and high

//first the pin will be low then after 200ms delay it will show or be high

void Request()

{

DDRD |= (1<<DHT11_PIN);

PORTD &= ~(1<<DHT11_PIN);

_delay_ms(200);

PORTD |= (1<<DHT11_PIN);

}

//the following function will show th response of the sensor DHT11

void Response()

{

DDRD &= ~(1<<DHT11_PIN);

while(PIND & (1<<DHT11_PIN));

while((PIND & (1<<DHT11_PIN))==0);

while(PIND & (1<<DHT11_PIN));

}

//this function will receive the data, check for received bit 0 or 1

//if the pulse is greater than 30ms

//then it will set the logic or the PIN to high or low

uint8_t Receive_data()

{

for (int q=0; q<8; q++)

{

while((PIND & (1<<DHT11_PIN)) == 0);

_delay_us(30);

if(PIND & (1<<DHT11_PIN))

c = (c<<1)|(0x01);

else

c = (c<<1);

while(PIND & (1<<DHT11_PIN));

}

return c;

}

int main(void)

{

char data[5];

//the following line will show the LCD initiating

lcdinit();

//the LCD will be clear

lcd_clear();

//here we will enter or set the cursor on the LCD

lcd_gotoxy(0,0);

lcd_print("Humidity =");

lcd_gotoxy(0,1);

lcd_print("Temp = ");

while(1)

{

Request(); /* send start pulse */

Response(); /* receive response */

I_RH=Receive_data(); /* store first eight bit in I_RH */

D_RH=Receive_data(); /* store next eight bit in D_RH */

I_Temp=Receive_data(); /* store next eight bit in I_Temp */

D_Temp=Receive_data(); /* store next eight bit in D_Temp */

CheckSum=Receive_data();/* store next eight bit in CheckSum */

//THIS IF STATEMENT WILL SHOW ON THE LCD SCREEN IF THE SENSOR IS NOT WPRKING

//  The following message will show if the DATA THAT IS SUPOSED TO RECEVIE IS NOT CORRRECT

if ((I_RH + D_RH + I_Temp + D_Temp) != CheckSum)

{

lcd_gotoxy(0,0);

lcd_print("READ DHT11 FAILED");

}

//Here we will show the data of the sensor on the lcd screen

else

{

//we will delay reading the data for 2 second so th sensor has time to read the data

//after the data is readed it will sow on the screen

//if the data is not readed, then the screen will show a message for an error.

_delay_ms(2000);

itoa(I_RH,data,10);

lcd_gotoxy(11,0);

lcd_print(data);

lcd_print(".");

itoa(D_RH,data,10);

lcd_print(data);

lcd_print("%");

itoa(I_Temp,data,10);

lcd_gotoxy(6,1);

lcd_print(data);

lcd_print(".");

itoa(D_Temp,data,10);

lcd_print(data);

lcddata(0xDF);

lcd_print("C ");

itoa(CheckSum,data,10);

lcd_print(data);

lcd_print(" ");

}

_delay_ms(1000);

}

}