树莓派4B运行DHT11测试脚本报错：OverflowError: unsigned short超出最大值

云上老周

2026-8-20

问题描述

在树莓派4B上运行测试DHT11传感器的Python脚本时，触发OverflowError: unsigned short is greater than maximum错误。

测试代码：

import adafruit_dht, board

print("Current temperature is " + str(adafruit_dht.DHT11(board.D21).temperature))

完整报错信息：

Traceback (most recent call last):
  File "/home/murrakhm/Desktop/temp_v1.py", line 3, in <module>
    print("Current temperature is " + str(adafruit_dht.DHT11(board.D21).temperature))
  File "/home/murrakhm/.local/lib/python3.9/site-packages/adafruit_dht.py", line 274, in temperature
    self.measure()
  File "/home/murrakhm/.local/lib/python3.9/site-packages/adafruit_dht.py", line 219, in measure
    pulses = self._get_pulses_pulseio()
  File "/home/murrakhm/.local/lib/python3.9/site-packages/adafruit_dht.py", line 149, in _get_pulses_pulseio
    pulses.append(self.pulse_in.popleft())
OverflowError: unsigned short is greater than maximum

解决方法

更换传感器读取库：弃用adafruit_dht，改用更稳定的dht11库。
安装命令：

pip install dht11

示例代码：

import RPi.GPIO as GPIO
import dht11

GPIO.setwarnings(False)
GPIO.setmode(GPIO.BCM)
GPIO.cleanup()

sensor = dht11.DHT11(pin=21)
result = sensor.read()

if result.is_valid():
    print(f"Current temperature is {result.temperature}")
else:
    print(f"读取失败，错误码: {result.error_code}")

修复adafruit_dht库的溢出问题：找到库文件/home/murrakhm/.local/lib/python3.9/site-packages/adafruit_dht.py，修改_get_pulses_pulseio方法中的脉冲读取代码：
将第149行的：
```
pulses.append(self.pulse_in.popleft())
```
修改为：
```
pulses.append(int(self.pulse_in.popleft()))
```
通过将无符号短整型转换为Python原生int类型，避免溢出报错。
检查硬件连接：确认DHT11的VCC接3.3V（禁止接5V，会导致信号异常），GND可靠接地，DATA引脚连接GPIO21，必要时在DATA和VCC之间添加10kΩ上拉电阻，排除接触不良问题。