DHT22を使った温度、湿度表示プログラム

↓の3)で動かず苦労。

 

1) DHT22接続

GPIOは15に接続(どこでも良い)

2) Adafruit Install

pi@raspberrypi:~ $ sudo apt-get update

pi@raspberrypi:~ $ sudo apt-get install python3-pip

pi@raspberrypi:~ $ sudo python3 -m pip install --upgrade pip setuptools wheel

pi@raspberrypi:~ $ sudo pip3 install Adafruit_DHT

#インストール先は/usr/local/lib/python3.7/dist-packagesに入ります。

pi@raspberrypi:~ $ cd Adafruit_Python_DHT

pi@raspberrypi:~/Adafruit_Python_DHT $ sudo python3 setup.py install

3) "/usr/local/lib/python3.7/dist-packages/Adafruit_DHT/platform_detect.py"　書き換え

111行目あたりに以下を追加

elif match.group(1) == 'BCM2711':

return 3

 

4) DHT22_org.py

import Adafruit_DHT
from time import sleep

DHT_SENSOR = Adafruit_DHT.DHT22
DHT_PIN = 15

while True:
    humidity, temperature = Adafruit_DHT.read_retry(DHT_SENSOR, DHT_PIN)

    if humidity is not None and temperature is not None:
        print("Temp: {0:0.1f}C  Humidity: {1:0.1f}%".format(temperature, humidity))
        sleep(5)
    else:
        print("Failed.")

5) pi@raspberrypi:~ python3 ./DHT22_org.py