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Temperature and Humidity Sensor

DHT11 Sensor Documentation​

1. Introduction​

The DHT11 is a digital temperature and humidity sensor widely used in environmental monitoring projects. It provides temperature and humidity readings with moderate accuracy and is easy to use.

2. Technical Characteristics​

  • Temperature Range: 0 to 50°C (accuracy of ±2°C)
  • Humidity Range: 20% to 90% RH (accuracy of ±5% RH)
  • Operating Voltage: 3V to 5.5V
  • Interface: Digital (single wire)
  • Response Time: 1 second
  • Dimensions: 15.5 mm x 12 mm x 5.5 mm
  • Lifespan: More than 20,000 measurement cycles

3. Pin Configuration​

DHT11 Pinout

4. Using DHT11 with CircuitPython​

Library Installation:

  1. The library installs automatically if you use a code block that uses the DHT11 backpack in Elioblocs.

  2. Otherwise Install the library Adafruit CircuitPython DHT using the Library Bundle CircuitPython from Adafruit.

Code Example:

import time
import board
import adafruit_dht

# Initialize DHT11 sensor
dht11 = adafruit_dht.DHT11(board.IO15)

while True:
    temperature = dht11.temperature
    humidity = dht11.humidity
    
    print(f"Temp: {temperature} °C    Humidity: {humidity} %")
    time.sleep(2.0)
  • time.sleep(2.0) ensures the sensor is read every 2 seconds, which is recommended for reliable readings.

5. Common Applications​

  • Domestic weather stations
  • Humidity control systems
  • Home automation projects
  • IoT devices for environmental monitoring