使用Adafruit_DHT读取DHT11时遇Unknown platform错误求助

问题描述 #

将DHT11传感器连接至GPIO-12（物理引脚32），使用Adafruit_DHT库编写Python脚本读取温湿度时，触发RuntimeError: Unknown platform错误。已尝试重装库、更新库、将脚本移至Adafruit_DHT目录运行等操作，问题仍未解决。

报错栈 #

Traceback (most recent call last):
  File "/home/amir-pi/Wetter_Projekt/Adafruit_Python_DHT-1.4.1/test1.py", line 8, in <module>
    humidity, temperature = Adafruit_DHT.read_retry(sensor, pin)
                            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/amir-pi/Wetter_Projekt/Adafruit_Python_DHT-1.4.1/Adafruit_DHT/common.py", line 94, in read_retry
    humidity, temperature = read(sensor, pin, platform)
                            ^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/amir-pi/Wetter_Projekt/Adafruit_Python_DHT-1.4.1/Adafruit_DHT/common.py", line 80, in read
    platform = get_platform()
               ^^^^^^^^^^^^^^
  File "/home/amir-pi/Wetter_Projekt/Adafruit_Python_DHT-1.4.1/Adafruit_DHT/common.py", line 63, in get_platform
    raise RuntimeError('Unknown platform.')
RuntimeError: Unknown platform.

脚本代码 #

import Adafruit_DHT

# 配置传感器类型和引脚（DHT11，物理引脚32对应GPIO12）
sensor = Adafruit_DHT.DHT11
pin = 12

# 尝试读取温湿度数据
humidity, temperature = Adafruit_DHT.read_retry(sensor, pin)

# 检查数据是否读取成功
if humidity is not None and temperature is not None:
    print('温度={0:0.1f}°C 湿度={1:0.1f}%'.format(temperature, humidity))
else:
    print('读取传感器数据失败，请重试！')

解决方法 #

1. 手动指定平台类型 #

绕过库的自动平台检测，直接传入树莓派平台参数修改脚本：

import Adafruit_DHT
from Adafruit_DHT import Raspberry_Pi

sensor = Adafruit_DHT.DHT11
pin = 12

# 手动指定平台参数
humidity, temperature = Adafruit_DHT.read_retry(sensor, pin, platform=Raspberry_Pi)

if humidity is not None and temperature is not None:
    print('温度={0:0.1f}°C 湿度={1:0.1f}%'.format(temperature, humidity))
else:
    print('读取传感器数据失败，请重试！')

2. 切换到兼容新版系统的库 #

旧版Adafruit_Python_DHT（1.4.1）对新版树莓派OS（如Bookworm）支持较差，改用官方新版库：

• 卸载旧库：

  pip uninstall Adafruit_DHT
  

• 安装新版库及系统依赖：

  pip install adafruit-circuitpython-dht
  sudo apt-get install libgpiod2
  

• 新版脚本示例：

  import time
  import board
  import adafruit_dht
  
  # 初始化传感器，GPIO12对应board.D12
  dht_device = adafruit_dht.DHT11(board.D12)
  
  try:
      temperature = dht_device.temperature
      humidity = dht_device.humidity
      if humidity is not None and temperature is not None:
          print(f"温度={temperature:.1f}°C 湿度={humidity:.1f}%")
      else:
          print("读取传感器数据失败，请重试！")
  finally:
      dht_device.exit()
  

3. 修改旧库的平台检测逻辑 #

若坚持使用旧库，手动修改common.py的平台识别代码：

• 打开/home/amir-pi/Wetter_Projekt/Adafruit_Python_DHT-1.4.1/Adafruit_DHT/common.py
• 找到get_platform()函数，添加树莓派硬件标识检测：

  def get_platform():
      # 保留原有代码，新增以下判断
      with open('/proc/cpuinfo', 'r') as f:
          cpuinfo = f.read()
      if 'BCM2835' in cpuinfo or 'BCM2711' in cpuinfo:
          return Raspberry_Pi
      # 原有代码继续...
  

内容的提问来源于stack exchange，提问作者Amir004