ds18b20校验代码
时间: 2023-07-03 10:30:11 浏览: 81
以下是基于C语言的DS18B20校验代码示例:
```c
#include <stdio.h>
#include <stdlib.h>
#include <wiringPi.h>
#define DS18B20_PIN 7
int ds18b20_reset() {
int result;
pinMode(DS18B20_PIN, OUTPUT);
digitalWrite(DS18B20_PIN, LOW);
delayMicroseconds(480);
pinMode(DS18B20_PIN, INPUT);
delayMicroseconds(80);
result = digitalRead(DS18B20_PIN);
delayMicroseconds(400);
return result;
}
void ds18b20_write_bit(int bit) {
pinMode(DS18B20_PIN, OUTPUT);
digitalWrite(DS18B20_PIN, LOW);
if (bit) delayMicroseconds(6);
else delayMicroseconds(60);
pinMode(DS18B20_PIN, INPUT);
delayMicroseconds(10);
}
void ds18b20_write_byte(int byte) {
int i;
for (i = 0; i < 8; i++) {
ds18b20_write_bit(byte & 1);
byte >>= 1;
}
}
int ds18b20_read_bit() {
int result;
pinMode(DS18B20_PIN, OUTPUT);
digitalWrite(DS18B20_PIN, LOW);
delayMicroseconds(2);
pinMode(DS18B20_PIN, INPUT);
delayMicroseconds(10);
result = digitalRead(DS18B20_PIN);
delayMicroseconds(48);
return result;
}
int ds18b20_read_byte() {
int i, result = 0;
for (i = 0; i < 8; i++) {
result >>= 1;
if (ds18b20_read_bit()) result |= 0x80;
}
return result;
}
float ds18b20_read_temperature() {
int temperature_l, temperature_h;
float temperature;
ds18b20_reset();
ds18b20_write_byte(0xcc);
ds18b20_write_byte(0x44);
delay(800);
ds18b20_reset();
ds18b20_write_byte(0xcc);
ds18b20_write_byte(0xbe);
temperature_l = ds18b20_read_byte();
temperature_h = ds18b20_read_byte();
temperature = (temperature_h << 8) + temperature_l;
temperature *= 0.0625;
return temperature;
}
int main(int argc, char **argv) {
float temperature;
wiringPiSetup();
temperature = ds18b20_read_temperature();
printf("Temperature: %.2f Celsius\n", temperature);
return 0;
}
```
其中,ds18b20_reset() 函数用于重置DS18B20传感器,ds18b20_write_bit() 函数用于写入一个位,ds18b20_write_byte() 函数用于写入一个字节,ds18b20_read_bit() 函数用于读取一个位,ds18b20_read_byte() 函数用于读取一个字节,ds18b20_read_temperature() 函数用于读取温度值。在 main() 函数中,使用 wiringPiSetup() 函数进行初始化,并调用 ds18b20_read_temperature() 函数读取温度值并打印。