树莓派风扇散热

fan.py

#!/usr/bin/env python3
# -*- coding: utf-8 -*-
import datetime
import os
import time
import RPi.GPIO as GPIO

# GPIO14 08号引脚
GPIO_OUT = 14
# 日志位置
LOG_PATH = '/tmp/fan_control.log'
# 调试模式
IS_DEBUG = False


class Fan:
    def __init__(self):
        # BOARD编号方式，基于插座引脚编号
        GPIO.setmode(GPIO.BCM)
        GPIO.setwarnings(False)
        # 设置08号引脚为输出模式
        GPIO.setup(GPIO_OUT, GPIO.OUT)

    """
    读取 CPU 温度
    """
    def read_cpu_temperature(self):
        with open("/sys/class/thermal/thermal_zone0/temp", 'r') as f:
            temperature = float(f.read()) / 1000
        log('DEBUG', 'Current CPU temperature is {}'.format(temperature))
        return temperature

    """
    启动风扇
    """
    def start_fan(self):
        log('INFO', 'Power on')
        GPIO.output(GPIO_OUT, GPIO.HIGH)

    """
    停止风扇
    """
    def stop_fan(self):
        log('INFO', 'Power off')
        GPIO.output(GPIO_OUT, GPIO.LOW)

    """
    控制风扇
    """
    def control_fan(self):
        # 标记风扇开关状态
        is_closed = True
        try:
            while True:
                temperature = self.read_cpu_temperature()
                if is_closed:
                    # 温度高于50°即启动风扇
                    if temperature >= 50:
                        self.start_fan()
                        is_closed = False
                else:
                    # 温度低于45°即停止风扇
                    if temperature <= 43:
                        self.stop_fan()
                        is_closed = True
                # 每10s检查一次
                time.sleep(10)
        except Exception as e:
            GPIO.cleanup()
            log('ERROR', e)


"""
日志
:param level 级别
:param msg 消息
"""
def log(level, msg):
    log_msg = '{} [{}] {}'.format(datetime.datetime.now(), level, msg)
    if not IS_DEBUG and level == 'DEBUG':
        return
    try:
        with open(LOG_PATH, 'a') as f:
            f.write(log_msg + '\n')
    except Exception as e:
        print("Unable to log: {}".format(e))


if __name__ == '__main__':
    os.environ["TZ"] = 'Asia/Shanghai'
    time.tzset()
    log('INFO', '[*] Started')
    Fan().control_fan()
    log('INFO', '[*] Quit')