调整Raspberry Pi Zero上DHT22的温度输出值技术求助

Got it, let's tackle that temperature offset problem you're facing with your DHT22 sensor. Since the Pi Zero's heat is making the sensor read 5°C higher than the actual ambient temperature, we just need to add a simple correction to subtract that 5-degree bias from the raw reading.

Here's the modified script with the fix, plus a few defensive checks to handle cases where the sensor might fail to read (to avoid runtime errors):

streamer = Streamer(bucket_name=BUCKET_NAME, bucket_key=BUCKET_KEY, access_key=ACCESS_KEY)
while True:
    humidity, temp_c = Adafruit_DHT.read_retry(Adafruit_DHT.DHT22, 4)
    
    # Apply temperature correction: subtract 5°C to account for Pi Zero heat
    if temp_c is not None:
        corrected_temp_c = temp_c - 5.0
    else:
        corrected_temp_c = temp_c  # Keep None value if sensor read fails
    
    if METRIC_UNITS:
        streamer.log(SENSOR_LOCATION_NAME + " Temperature(C)", corrected_temp_c)
    else:
        # Use corrected Celsius value to calculate accurate Fahrenheit
        temp_f = format(corrected_temp_c * 9.0 / 5.0 + 32.0, ".2f")
        streamer.log(SENSOR_LOCATION_NAME + " Temperature(F)", temp_f)
    
    # Add defensive check for humidity before formatting
    if humidity is not None:
        humidity = format(humidity,".2f")
    streamer.log(SENSOR_LOCATION_NAME + " Humidity(%)", humidity)
    
    streamer.flush()
    time.sleep(60*MINUTES_BETWEEN_READS)

Key Changes Explained: #

• Temperature Correction: We added a check to ensure temp_c isn't None (since read_retry can sometimes fail to get a valid reading) before subtracting 5°C. This prevents a TypeError if the sensor returns no data.
• Consistent Unit Adjustment: The Fahrenheit calculation now uses the corrected Celsius value, so both metric and imperial outputs will reflect the accurate ambient temperature.
• Humidity Safety Check: Added a quick validation for humidity to avoid formatting errors if the humidity reading fails — it's a small defensive tweak to make the script more robust.

That should give you an accurate ambient temperature, accounting for the heat from your Pi Zero's case-mounted sensor!

内容的提问来源于stack exchange，提问作者Peter Kold