This guide covers the specifications, wiring instructions, and code examples for using Adafruit DHT11, DHT22, and AM2302 temperature and humidity sensors…
This document provides an overview of low-cost DHT temperature and humidity sensors (DHT11, DHT22, and AM2302), detailing their specifications and differences. It explains that these sensors consist of a capacitive humidity sensor and a thermistor with an internal analog-to-digital converter.
| Power Supply | 3 to 5V power and I/O |
|---|---|
| Max Current | 2.5mA max current use during conversion |
| Humidity Range (DHT11) | 20-80% humidity readings with 5% accuracy |
| Temperature Range (DHT11) | 0-50°C temperature readings ±2°C accuracy |
| Sampling Rate (DHT11) | No more than 1 Hz sampling rate |
| Humidity Range (DHT22/AM2302) | 0-100% humidity readings with 2-5% accuracy |
| Temperature Range (DHT22/AM2302) | -40 to 80°C temperature readings ±0.5°C accuracy |
| Sampling Rate (DHT22/AM2302) | No more than 0.5 Hz sampling rate |
Yes, it is recommended to place a 10 Kohm resistor between VCC and the data line. For DHT11, it is required; for DHT22/AM2302, it can sometimes be omitted if an internal pull-up exists.
Yes, you can add as many DHT sensors as needed by connecting each to an individual digital pin.