使用C语言写一个通过DHT11检测温湿度的代码
时间: 2023-04-11 10:01:19 浏览: 67
我可以回答这个问题。以下是一个使用C语言编写的通过DHT11检测温湿度的代码示例:
#include <stdio.h>
#include <stdlib.h>
#include <wiringPi.h>
#include <stdint.h>
#define MAX_TIMINGS 85
#define DHT_PIN 7
int data[5] = { 0, 0, 0, 0, 0 };
void read_dht_data()
{
uint8_t last_state = HIGH;
uint8_t counter = 0;
uint8_t j = 0, i;
data[0] = data[1] = data[2] = data[3] = data[4] = 0;
pinMode(DHT_PIN, OUTPUT);
digitalWrite(DHT_PIN, LOW);
delay(18);
digitalWrite(DHT_PIN, HIGH);
delayMicroseconds(30);
pinMode(DHT_PIN, INPUT);
for (i = 0; i < MAX_TIMINGS; i++)
{
counter = 0;
while (digitalRead(DHT_PIN) == last_state)
{
counter++;
delayMicroseconds(1);
if (counter == 255)
{
break;
}
}
last_state = digitalRead(DHT_PIN);
if (counter == 255)
break;
if ((i >= 4) && (i % 2 == 0))
{
data[j / 8] <<= 1;
if (counter > 16)
data[j / 8] |= 1;
j++;
}
}
if ((j >= 40) && (data[4] == ((data[0] + data[1] + data[2] + data[3]) & 0xFF)))
{
float h = (float)((data[0] << 8) + data[1]) / 10;
if (h > 100)
{
h = data[0]; // for DHT11
}
float c = (float)(((data[2] & 0x7F) << 8) + data[3]) / 10;
if (c > 125)
{
c = data[2]; // for DHT11
}
if (data[2] & 0x80)
{
c = -c;
}
printf("Humidity = %.1f %% Temperature = %.1f *C\n", h, c);
}
else
{
printf("Data not good, skip\n");
}
}
int main(void)
{
if (wiringPiSetup() == -1)
exit(1);
while (1)
{
read_dht_data();
delay(2000);
}
return 0;
}