{"product_id":"aht21b-temperature-humidity-sensor-module-i2c-high-accuracy","title":"AHT21B Temperature Humidity Sensor Module - I2C High Accuracy","description":"\u003ch1\u003eAHT21B Temperature and Humidity Sensor Module – I2C Interface, ±2% RH Accuracy\u003c\/h1\u003e\n\n\u003cp\u003eThe AHT21B is a digital temperature and humidity sensor module using the I2C protocol. It delivers accurate measurements with a typical accuracy of ±2% RH for humidity and ±0.3°C for temperature. Designed for low-power applications, this sensor is ideal for environmental monitoring, weather stations, and IoT data logging.\u003c\/p\u003e\n\n\u003ch2\u003eKey Specifications\u003c\/h2\u003e\n\u003ctable\u003e\n  \u003cthead\u003e\u003ctr\u003e\n\u003cth\u003eSpecification\u003c\/th\u003e\n\u003cth\u003eValue\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n  \u003ctbody\u003e\n    \u003ctr\u003e\n\u003ctd\u003eSupply Voltage\u003c\/td\u003e\n\u003ctd\u003e1.8V – 3.6V DC\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eHumidity Range\u003c\/td\u003e\n\u003ctd\u003e0% to 100% RH\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eTemperature Range\u003c\/td\u003e\n\u003ctd\u003e-40°C to +85°C\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eHumidity Accuracy\u003c\/td\u003e\n\u003ctd\u003e±2% RH (typical)\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eTemperature Accuracy\u003c\/td\u003e\n\u003ctd\u003e±0.3°C (typical)\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eInterface\u003c\/td\u003e\n\u003ctd\u003eI2C (address 0x38)\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003c\/tbody\u003e\n\u003c\/table\u003e\n\n\u003ch2\u003eWhat You Can Build With This\u003c\/h2\u003e\n\u003cul\u003e\n  \u003cli\u003e\u003ca href=\"\/products\/kit-animated-weather-station-display\"\u003eIndoor weather station with real-time display\u003c\/a\u003e\u003c\/li\u003e\n  \u003cli\u003e\u003ca href=\"\/products\/kit-greenhouse-climate-monitor-kit-with-arduino-uno-plus-sensors\"\u003eGreenhouse or terrarium climate monitor\u003c\/a\u003e\u003c\/li\u003e\n  \u003cli\u003eIncubator or mushroom farm humidity controller\u003c\/li\u003e\n  \u003cli\u003e\u003ca href=\"\/products\/kit-server-room-temperature-monitor-kit-v4\"\u003eServer room temperature and humidity alert system\u003c\/a\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003eCompatibility\u003c\/h2\u003e\n\u003cp\u003eThis module works with any microcontroller supporting I2C, such as Arduino Uno, Nano, ESP32, ESP8266, and Raspberry Pi. The AHT21B operates at 1.8V–3.6V, making it directly compatible with 3.3V boards. For 5V systems like Arduino Uno, a logic level converter is recommended to avoid damage, though many users report success with direct I2C connection due to the sensor's 5V-tolerant pins.\u003c\/p\u003e\n\n\u003ch2\u003eWiring Notes\u003c\/h2\u003e\n\u003cp\u003eConnect VCC to 3.3V, GND to ground, SDA to the I2C data line (A4 on Arduino Uno), and SCL to the I2C clock line (A5 on Uno). The module includes built-in pull-up resistors, so external resistors are not required. Keep wires short and avoid noise sources for stable readings.\u003c\/p\u003e\n\n\u003ch2\u003eWhy Buy from Compoden\u003c\/h2\u003e\n\u003cp\u003eEvery component is sourced from verified suppliers and tested for compatibility before listing. We've spent 10 years building projects for makers, schools, and institutions across India. Ships from Bengaluru in 3-5 days. If defective on arrival, replace within 7 days.\u003c\/p\u003e\n\n\u003cdetails\u003e\u003csummary\u003eIs this compatible with Arduino?\u003c\/summary\u003e\u003cp\u003eYes, the AHT21B uses I2C and works with Arduino boards. Use the AHTxx library for easy interfacing. For 5V Arduinos, a level shifter is advised but often not essential due to 5V-tolerant pins.\u003c\/p\u003e\u003c\/details\u003e\n\u003cdetails\u003e\u003csummary\u003eWhat is the sampling rate?\u003c\/summary\u003e\u003cp\u003eThe sensor provides a new reading approximately every 2 seconds (0.5 Hz). It is not suitable for high-speed applications but perfect for periodic environmental logging.\u003c\/p\u003e\u003c\/details\u003e\n\u003cdetails\u003e\u003csummary\u003eCan it be used outdoors?\u003c\/summary\u003e\u003cp\u003eThe bare module is not waterproof. For outdoor use, house it inside a weather-proof enclosure with a breathable membrane to allow humidity sensing while protecting from direct moisture and dust.\u003c\/p\u003e\u003c\/details\u003e\n\u003cdiv class=\"compoden-handoff\" style=\"margin-top:24px;padding:16px;background:#f0f4ff;border-left:4px solid #2B4D8F;border-radius:4px;\"\u003e\n  \u003cp style=\"margin:0 0 6px 0;font-weight:600;color:#1A3560;\"\u003e📦 Free Setup Handoff Document Included\u003c\/p\u003e\n  \u003cp style=\"margin:0;font-size:0.95em;color:#333;\"\u003eEvery Compoden order includes a free setup handoff document — step-by-step instructions to get your component working within minutes. Download it via QR code on your package. The handoff document is also trained to help you troubleshoot the majority of problems.\u003c\/p\u003e\n\u003c\/div\u003e\n","brand":"Compoden","offers":[{"title":"Default Title","offer_id":53444953866605,"sku":"CDN-0232","price":110.0,"currency_code":"INR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0999\/3997\/5533\/files\/download_b0007f1a-33a6-4363-8fae-5eb4e0a1bc06.jpg?v=1781591509","url":"https:\/\/compoden.com\/products\/aht21b-temperature-humidity-sensor-module-i2c-high-accuracy","provider":"Compoden","version":"1.0","type":"link"}