DS18B20驱动程序

DS18B20是一种数字温度传感器，它使用1线数字接口进行通信。以下是一个简单的DS18B20驱动程序示例，使用C语言编写：

#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <string.h>
#include <wiringPi.h>

#define MAX_TIMING 85

int pin = 7;

int read_dht11_dat()
{
    uint8_t data[5] = {0, 0, 0, 0, 0};
    uint8_t last_state = HIGH;
    uint8_t counter = 0;
    uint8_t j = 0, i;

    pinMode(pin, OUTPUT);
    digitalWrite(pin, LOW);
    delay(18);
    digitalWrite(pin, HIGH);
    delayMicroseconds(40);
    pinMode(pin, INPUT);

    for (i = 0; i < MAX_TIMING; i++)
    {
        counter = 0;
        while (digitalRead(pin) == last_state)
        {
            counter++;
            delayMicroseconds(1);
            if (counter == 255)
            {
                break;
            }
        }
        last_state = digitalRead(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 temp = ((data[2] & 0x7F) << 8 | data[3]) / 10.0;
        if (data[2] & 0x80)
        {
            temp *= -1;
        }
        printf("Temperature = %.1f °C\n", temp);
        return 0;
    }
    else
    {
        printf("Data not good, skip\n");
        return -1;
    }
}

int main()
{
    if (wiringPiSetup() == -1)
        exit(1);

    while (1)
    {
        read_dht11_dat();
        delay(1000);
    }

    return 0;
}

这个程序使用WiringPi库来控制GPIO引脚。它通过DS18B20传感器读取温度数据，并将其打印到终端上。该程序应该能够在树莓派和其他基于Linux的嵌入式设备上运行。