{"title":"Adafruit HDC3021 Precision Temperature & Humidity Sensor","handle":"adafruit-hdc3021-precision-temperature-humidity-sensor-ada5989","url":"/products/adafruit-hdc3021-precision-temperature-humidity-sensor-ada5989","description":"The Adafruit HDC3021 is a high-precision I²C temperature and humidity sensor breakout featuring the TI HDC302x series chip. With typical humidity accuracy of ±0.5% RH (and just 0.19% long-term drift) and temperature accuracy of ±0.1°C, it's one of the most accurate environmental sensors available at this price point.\n\nThe sensor operates across 1.8–5V power and logic levels with no external level shifters required, making it compatible with virtually any microcontroller or single-board computer. Four selectable I²C addresses allow multiple sensors on one bus for multi-zone monitoring. STEMMA QT / Qwiic connectors on the breakout enable solderless I²C connections.\n\nKey Features\n\n\n±0.5% Typical Humidity Accuracy – With 0.19% long-term drift for reliable readings over time\n\n±0.1°C Typical Temperature Accuracy – High-precision environmental monitoring\n\nI²C Interface – Simple two-wire digital communication\n\n4 Selectable I²C Addresses – Run multiple sensors on one bus\n\n1.8–5V Compatible – No level shifters needed for any common microcontroller\n\nSTEMMA QT / Qwiic Connectors – Solderless I²C connection\n\nConfigurable Settings – Adjustable sensor rate, power mode, heater, alerts, and offsets\n\nNIST Tracking ID – Built-in traceability for calibration and compliance\n\nArduino and CircuitPython Libraries – Full-featured driver support with example code\n\n\nIdeal For\n\nHigh-precision environmental monitoring\nIndoor air quality and HVAC systems\nMulti-zone temperature and humidity tracking\nScientific and industrial data logging\n\n\nPackage Contents\n\n1× Adafruit HDC3021 Breakout Board – Fully assembled and tested with STEMMA QT connectors\n1× Header strip (unsoldered)\n\n\n\nImportant: This sensor ships with a protective polyamide sticker on top. Please remove it before use.\n\n\n\nNote: STEMMA QT / Qwiic cable not included. Header strip requires light soldering if using with a breadboard.\n\n\nResources\n\nTI HDC302x Datasheet\nArduino HDC302x Library (GitHub)\nCircuitPython HDC302x Library (GitHub)\nWhat is STEMMA QT?\n","vendor":"Adafruit","product_type":"physical","in_stock":false,"options":[],"variants":[{"id":977,"title":"Default Title","sku":"AF-5989","mpn":"ADA5989","price":17.33,"compare_at_price":0.0,"on_sale":false,"in_stock":false,"available_quantity":0,"option1":"Default Title"}]}