AM2301 A temperature and humidity sensor - DHT21, -40 to 80 °C, 3.3-5.5 V

Product overview

• Combined temperature and humidity sensor with digital output
• Temperature measurement range: -40 °C to +80 °C
• Humidity measurement range: 0 to 100 percent relative humidity
• Accuracy: ±0.5 °C and ±2 percent humidity
• Connection via 1-Wire protocol, four connections required
• Operating voltage: 3.3 to 5.5 V
• Factory-calibrated, raw calibration data available

Product description

This temperature and humidity sensor measures both values in a single housing and outputs the readings digitally. The 1-Wire protocol enables easy integration into measurement setups, but requires four separate connection lines for the power supply, ground, data line, and a spare connection. The operating voltage of 3.3 to 5.5 V is compatible with common microcontroller boards without additional voltage regulators.

The measurement accuracy of ±0.5 °C for temperature and ±2 percent for humidity enables reliable monitoring even in demanding applications. The measurement range of -40 to +80 °C covers exceptionally cold environments, making the sensor suitable for outdoor measurements in winter regions, while the humidity range of 0 to 100 percent covers all common application areas. Since the sensor is factory-calibrated, adjustment before use is not required. The raw calibration data is available for applications with special requirements.

Typical applications include environmental monitoring in living spaces, warehouses, and greenhouses. The sensor reliably reports humidity values even at extreme temperatures, making it suitable for monitoring cold chains or outdoor storage areas. In humidity measurement networks with multiple sensors, the devices can be connected in series because the 1-Wire protocol allows multiple modules to operate on a single line.

Operation requires a microcontroller that supports the 1-Wire protocol or provides a library for it. The four required connections must be taken into account during setup, particularly where space is limited. Depending on the installation location, protection against moisture is required because the housing itself is not waterproof.

Safety information

This module is intended exclusively for prototype construction and testing and development purposes and is not suitable for installation in household electrical circuits. Work on or near electrical installations must be carried out by qualified electricians. When operating in damp environments, consult a qualified electrician before commissioning to ensure contact resistance and insulation safety.

Package contents

• 1 x AM2301A / DHT21 temperature & humidity sensor