DHT22 도착!

저장소 손보고

pi@raspberrypi:~/src $ sudo apt-get update Get:1 http://archive.raspberrypi.org/debian bullseye InRelease [23.6 kB] Get:2http://raspbian.raspberrypi.org/raspbian bullseye InRelease [15.0 kB] Get:3 http://raspbian.raspberrypi.org/raspbian bullseye/main armhf Packages [13.2 MB] Get:4 http://archive.raspberrypi.org/debian bullseye/main armhf Packages [314 kB] Fetched 13.6 MB in 25s (534 kB/s)                                                                                                 Reading package lists... Done N: Repository ' http://raspbian.raspberrypi.org/raspbian bullseye InRelease' changed its 'Suite' value from 'stable' to 'oldstable' pi@raspberrypi:~/src $ sudo apt full-upgrade

[링크 : https://forums.raspberrypi.com/viewtopic.php?t=318302]

 

pip를 이용하여 패키지 설치하고

$ sudo apt-get install python3-pip

[링크 : https://foreverhappiness.tistory.com/67] // pip3가 아니다 ㅠㅠ

 

adafruit_dht 패키지 설치하고

$ sudo pip3 install Adafruit_DHT Looking in indexes: https://pypi.org/simple, https://www.piwheels.org/simple Collecting Adafruit_DHT   Downloading Adafruit_DHT-1.4.0.tar.gz (15 kB) Building wheels for collected packages: Adafruit-DHT   Building wheel for Adafruit-DHT (setup.py) ... done   Created wheel for Adafruit-DHT: filename=Adafruit_DHT-1.4.0-cp39-cp39-linux_armv7l.whl size=26725 sha256=6d328e4cac264d9807d07a3f20bbc7eb687bf002ae850b3dcfdae1d5fc4a9a64   Stored in directory: /root/.cache/pip/wheels/2b/75/fa/27f8bc06878df2b751d348ad98e92361f78ea9f9640c7e6277 Successfully built Adafruit-DHT Installing collected packages: Adafruit-DHT Successfully installed Adafruit-DHT-1.4.0

 

소스는 adafruit 에서 만든걸 써서 별거 없는데

import Adafruit_DHT as dht import time while True:     humidity, temperature = dht.read_retry(dht.DHT22, 4)     print("Temp={0:0.1f}*C  Humidity={1:0.1f}%".format(temperature, humidity))    time.sleep(1)

[링크 : https://kdjun97.github.io/iot/raspberry-pi-dht22/]

 

예상외로 읽는데 실패가 좀 많은지 의외로 빈번하게 4초 정도 걸리는 경우가 나온다.

pi@raspberrypi:~/src $ time python sen.py  Temp=26.6*C  Humidity=55.6% Temperature in Celsius : 26.74 C Pressure : 1003.37 hPa real 0m3.937s user 0m0.370s sys 0m0.060s pi@raspberrypi:~/src $ time python sen.py  Temp=26.6*C  Humidity=55.5% Temperature in Celsius : 26.74 C Pressure : 1003.42 hPa real 0m1.415s user 0m0.352s sys 0m0.058s

 

python 에서 멀티 쓰레드로 해서 읽어오게 해야하나..