DHT11 Digital Temperature and Humidity Sensor (CHN)

Description

The DHT11 Digital Temperature and Humidity Sensor (CHN) is a low-cost, single-wire digital sensor designed for basic ambient temperature and relative humidity measurement in hobbyist, educational, and cost-sensitive applications. The CHN designation indicates this is a China-manufactured variant of the DHT11, offering the same basic functionality and pinout as the original ASAIR sensor at a more accessible price point.

The sensor combines a resistive humidity sensing element with an NTC temperature measurement component and an integrated 8-bit microcontroller, delivering a digital signal over a simple single-wire interface. The CHN variant is factory-calibrated with coefficients stored in on-chip memory, though batch-to-batch consistency may vary more than with the original ASAIR chip.

The DHT11 (CHN) provides humidity measurements from 20% to 90% RH with ±5% RH accuracy, and temperature measurements from 0°C to 50°C with ±2°C accuracy. The sensor operates from 3.3V to 5.5V DC, drawing approximately 1mA during measurement and 60µA in standby. The single-wire protocol requires only one data pin, plus power and ground.

Important Note: This is a basic, cost-sensitive sensor with limitations that should be understood before use. The CHN variant may exhibit greater unit-to-unit variation than the original ASAIR DHT11. Its 1°C/1%RH resolution and ±2°C/±5%RH accuracy make it unsuitable for precision applications. The sampling rate is limited to once every 1–2 seconds. The resistive humidity element can drift over long-term exposure to extreme humidity or contaminants. For higher accuracy or wider measurement ranges, consider the DHT22 (AM2302) or a digital sensor like the SHT series. The sensor is not waterproof and should be kept dry.

Whether you are building a simple weather station, a humidity controller, or an educational project, the DHT11 (CHN) provides a reliable, affordable entry point for basic digital environmental sensing.

Features

• CHN variant DHT11 sensor — Cost-effective China-manufactured alternative to the original ASAIR chip

• Calibrated digital output — No external trimming required; calibration coefficients stored on-chip

• Single-wire interface — Requires only one data pin plus power and ground

• Combined temperature and humidity sensing — Resistive humidity element and NTC temperature component

• 3.3V to 5.5V operation — Compatible with Arduino, ESP32, and other microcontrollers

• Low power consumption — ~1mA measuring, ~60µA standby

• Compact 4-pin package — Standard 0.1″ pin spacing for breadboard and PCB mounting

• Wide application range — Weather stations, HVAC, dehumidifiers, data loggers

• Cost-effective — Affordable solution for basic environmental sensing in volume projects

Technical Specifications