格安(1コイン以下)のケースとファンのセットを入手したので、試してみました。
とりあえず動きました
[pwm制御]
トランジスタ 2SC1815-GR
配線
E-->Pi GND
C-->fan GND
B-->100Ω抵抗-->Pi GPIO18
fan Vcc --> Pi 5V
sample script
#!/usr/bin/env python
# -*- coding: utf-8 -*-
import RPi.GPIO as GPIO
import time
DEBUG=True
GPIO_PWM = 18
Hz = 60
def get_cpu_temp():
with open("/sys/class/thermal/thermal_zone0/temp", "r") as f:
t=f.read()
return int(t)/1000
def fanctl_pwm():
"""
cpu temp,duty
"""
td=(
(29,0),
(30,25),
(35,50),
(40,60),
(41,65),
(43,70),
(45,75),
(46,80),
(48,90),
(49,95),
(50,98),
(51,100),
)
"""
td=(
(45,0),
(46,100),
)
"""
GPIO.setmode(GPIO.BCM)
GPIO.setup(GPIO_PWM, GPIO.OUT)
p = GPIO.PWM(GPIO_PWM, Hz)
try:
duty = 100
p.start(duty)
time.sleep(1)
while True:
cpu_temp = get_cpu_temp()
duty = 100
for x in td:
if DEBUG:
print "x(0)" + str(x[0]) + " C" ,
print "x(1)" + str(x[1]) + " %"
if x[0] >= cpu_temp:
duty = x[1]
break
elif x[0] > cpu_temp:
duty = 0
break
if DEBUG:
print "cpu temp=" + str(cpu_temp) + " C"
print "fun duty=" + str(duty) + "%"
p.ChangeDutyCycle(duty)
time.sleep(30)
except Exception as e:
print "Exception : " + str(e)
finally:
p.stop()
GPIO.cleanup()
if __name__ == "__main__":
time.sleep(1)
fanctl_pwm()
