atmega128 dht11 + usart 시리얼통신

아래에 첨부파일 있음. 폴더 안에 다 들어가 있다

 

main.c

/*
 * dht11_0205_final.c
 *
 * Created: 2021-02-05 오후 2:37:53
 * Author : User
 */ 

#define F_CPU 16000000UL
#include <stdio.h>
#include <string.h>
#include <avr/io.h>
#include <util/delay.h>
#include "dht11.h"
#include "uart.h"

int main(){
	uint8_t data = 0;
	char buf[40] = {0,};
	USART_Init();
		
	while (1){
		dht11_getdata(0, &data);
		sprintf(buf, "Temp:%d", data);
		strTransmit(buf);
		memset(buf, 0x00, 40);
		_delay_ms(1000);
		
		dht11_getdata(1, &data);
		sprintf(buf, "//Humi:%d", data);
		strTransmit(buf);
		memset(buf, 0x00, 40);
		_delay_ms(1000);		
	}
	
}

dht11.h

/*
 * dht11.h
 *
 * Created: 2021-02-05 오후 2:53:57
 *  Author: User
 */ 


#ifndef DHT11_H_
#define DHT11_H_

#define DHT11_ERROR 255

#define DHT11_DDR DDRF
#define DHT11_PORT PORTF
#define DHT11_PIN PINF
#define DHT11_INPUTPIN PF1

void dht11_getdata(uint8_t num, uint8_t *data);
uint8_t getdata(uint8_t select);


#endif /* DHT11_H_ */

dht11.c

/*
 * dht11.c
 *
 * Created: 2021-02-05 오후 3:01:48
 *  Author: User
 */ 

#define F_CPU 16000000UL
#include <stdio.h>
#include <string.h>
#include <avr/io.h>
#include <util/delay.h>
#include "dht11.h"

/* get data from dht11 */
uint8_t getdata(uint8_t select) {
	uint8_t bits[5];
	uint8_t i,j = 0;
	
	memset(bits, 0, sizeof(bits));
	
	//reset port
	DHT11_DDR |= (1<<DHT11_INPUTPIN); //output
	DHT11_PORT |= (1<<DHT11_INPUTPIN); //high
	_delay_ms(100);
	
	//send request
	DHT11_PORT &= ~(1<<DHT11_INPUTPIN); //low
	_delay_ms(18);
	//-- MCU pulls up voltage and waits for DHT response (20-40us)
	DHT11_PORT |= (1<<DHT11_INPUTPIN); //high
	_delay_us(1);
	DHT11_DDR &= ~(1<<DHT11_INPUTPIN); //input
	_delay_us(39);
	//--
	
	//check start condition 1 (low)
	if((DHT11_PIN & (1<<DHT11_INPUTPIN))) {
		return DHT11_ERROR;
	}
	_delay_us(80);
	//check start condition 2 (high)
	if(!(DHT11_PIN & (1<<DHT11_INPUTPIN))) {
		return DHT11_ERROR;
	}
	_delay_us(80);
	
	//read the data
	for (j=0; j<5; j++) { //read 5 byte
		uint8_t result=0;
		for(i=0; i<8; i++) {//read every bit
			while(!(DHT11_PIN & (1<<DHT11_INPUTPIN))); //wait for an high input
			_delay_us(30);
			if(DHT11_PIN & (1<<DHT11_INPUTPIN)) //if input is high after 30 us, get result
			result |= (1<<(7-i));
			while(DHT11_PIN & (1<<DHT11_INPUTPIN)); //wait until input get low
		}
		bits[j] = result;
	}
	
	//reset port
	DHT11_DDR |= (1<<DHT11_INPUTPIN); //output
	DHT11_PORT |= (1<<DHT11_INPUTPIN); //low
	_delay_ms(100);
	
	//check checksum
	if (bits[0] + bits[1] + bits[2] + bits[3] == bits[4]) {
		if (select == 0) { //return temperature
			return(bits[2]);
			} else if(select == 1){ //return humidity
			return(bits[0]);
		}
	}
	
	return DHT11_ERROR;
}

void dht11_getdata(uint8_t num, uint8_t *data){
	uint8_t buf = getdata(num);
	if(buf == DHT11_ERROR){
		;
	}
	else{
		*data = buf;
	}
}

uart.h

/*
 * uart.h
 *
 * Created: 2021-02-05 오전 10:23:17
 *  Author: User
 */ 

#ifndef UART_H_
#define UART_H_

void USART_Init(void);
unsigned char USART_Receive(void);
void USART_Transmit(unsigned char data);
void strTransmit(char *str);

#endif /* UART_H_ */

uart.c

/*
 * uart.c
 *
 * Created: 2021-02-05 오전 10:33:46
 *  Author: User
 */ 


#include <avr/io.h>
#include "uart.h"


void USART_Init(void)
{
	UCSR0A=0x00; // clear
	UCSR0B=(1<<RXEN0) | (1<<TXEN0); // Rx, Tx Enable
	UCSR0C=(0<<UCSZ02) | (1<<UCSZ01) | (1<<UCSZ00); // Tx data len : 8-bit
	
	UBRR0H=0;
	UBRR0L=103; // baudrate 9600bps
}

unsigned char USART_Receive(void)
{
	while(!(UCSR0A & (1<<RXC0))); // Wait for data to be received
	return UDR0; // Get and return received data form buffer
}

void USART_Transmit(unsigned char data)
{
	while(!(UCSR0A & (1<<UDRE))); // Wait for empty transmit buffer
	UDR0=data; // Put data into buffer, sends the  data
}

void strTransmit(char *str) {
	while (*str) {
		USART_Transmit(*str);
		str++;
	}
	USART_Transmit(10); // 개행문자
}

 

dht11_0205_final.zip

0.06MB

 

 

https://jdselectron.tistory.com/69

[ATmega128] DHT11(온습도 센서) 제어

dht11은 위의 블로그 참고함