Description
Reviews
| Brand | - |
| Category | Robotics / STEM Teaching Tools / Sensors |
| Origin | - |
| Model Number | AHT21B |
| Measurement Range (Temperature) | -40°C to +85°C |
| Measurement Range (Humidity) | 0% to 100% RH |
| Accuracy (Temperature) | ±0.3°C |
| Accuracy (Humidity) | ±2% RH |
| Communication Interface | I2C |
| Supply Voltage | 2.2V to 5.5V DC |
| Response Time | < 8 seconds |
| Package Type | SMD Module |
| Application | HVAC, Smart Home, Industrial Monitoring |
Anonymous
Mar 31, 2026
Rating: 4/5
Good value, fast shipping
The module works as described. Humidity response is quick. Only giving 4 stars because the documentation could be slightly more detailed regarding register maps, but standard libraries work fine.
Anonymous
Mar 26, 2026
Rating: 5/5
Highly recommended
This is my go-to sensor for any project requiring environmental data. The integration is seamless, and the data consistency over time is impressive.
Anonymous
Mar 24, 2026
Rating: 4/5
Solid performance
Works right out of the box. The soldering pads are large enough for hand soldering if you don't have a reflow oven. Readings match my expensive benchtop unit within expected tolerance.
Anonymous
Mar 22, 2026
Rating: 5/5
Low power consumption
Great for battery-powered IoT devices. The sleep mode current is incredibly low, allowing my device to run for months on a single coin cell.
Anonymous
Mar 22, 2026
Rating: 5/5
Perfect for agricultural monitoring
We deployed twenty of these in our prototype greenhouse system. They handle the high humidity environment well without drifting. Very reliable for the price point.
Anonymous
Mar 19, 2026
Rating: 5/5
Excellent precision for hobby projects
I integrated this sensor into my home weather station and the readings are consistently accurate compared to my calibrated reference meter. The I2C communication is stable and easy to implement with Arduino.
Q: Does this module come with a protective filter?
A: The standard module includes a basic dust filter. For environments with heavy particulate matter or corrosive gases, we recommend adding an external membrane filter.
Q: What is the maximum cable length for the I2C connection?
A: For standard I2C speeds (100kHz), we recommend keeping cables under 30cm for optimal reliability without pull-up resistor adjustments. For longer distances, consider using an I2C extender or buffer.
Q: Can I use 3.3V logic levels?
A: Absolutely. The sensor operates between 2.2V and 5.5V, making it directly compatible with both 3.3V and 5V microcontroller logic levels without a level shifter.
Q: How often should I calibrate this sensor?
A: The AHT21B is factory calibrated and typically maintains accuracy for years under normal operating conditions. Recalibration is generally only necessary if the sensor is exposed to extreme conditions beyond its specifications.
Q: Is this compatible with Raspberry Pi?
A: Yes, the AHT21B uses the I2C protocol which is fully supported by Raspberry Pi GPIO pins. You will need to enable the I2C interface in the raspi-config settings.
Zao Boshi Insulated Food Cart - Programmable Banquet Warmer for Buns, Breakfast Items, and Hotel Dry/Wet Dishes
$11,566.00
![Lichuan JK [Blood Oath] - Original Authentic Japanese Dark Style Embroidered Sailor Suit - Spring/Autumn Set](https://www.gosteppe.com/cache/small/product/269363/legacy-main-0b86f0b7795c15ee2c8be0d3.webp)
Lichuan JK [Blood Oath] - Original Authentic Japanese Dark Style Embroidered Sailor Suit - Spring/Autumn Set
$59.00
Sink Storage Rack Stainless Steel No-Drill Kitchen Sponge Steel Wool Cloth Pot Lid Organizer Wall-Mounted Drain Rack
$4.93
Sketch Blending Stump Set for Artists - Detail Highlight and Shadow Smudging Tools with Replacement Tips
$14.80
Softening Agent for Board Arcs Melamine Softener Eco-Friendly Board Paint-Free Board Whole House Customization Arc Softener
$9.30
Car Tire Stone Removal Tool - Hook Picker for Cleaning Pebbles from Vehicle Treads
$3.90
Electrical Box with PLC System and VFD for Fans and Pumps
$2,519.00
Zunjue Watercolor Sketchbook 300g Fabric-Covered Journal – Portable Acrylic Marker Book, 100% Cotton Flip-Style Concertina Drawing Paper
$13.70
French Imported Arches Watercolor Paper, Handmade Cotton Pulp 300g Full/Half/4K/8K/16K/32K Rough/Medium/Fine Grain, 185g Cotton Pulp for Postcards and Watercolor Books
$20.80
![[Official Authentic] Zichao Bear Wanda Cinema Popcorn Acrylic Keychain Plush Doll Cute Toy](https://www.gosteppe.com/cache/small/product/269355/legacy-main-ae40bf0d9a6007e2f30a9130.webp)
[Official Authentic] Zichao Bear Wanda Cinema Popcorn Acrylic Keychain Plush Doll Cute Toy
$25.40
Heidelberg Printing Press Automatic Blanket Wash Cloth - Non-Woven Cleaning Fabric, 500m Roll
$3,185.00
Bucket Pack Natural Wood Colored Pencils Water-Soluble for Kids Coloring and Doodling
$6.65
Chunfei Grocery Store Yunm'an GR02 Gravel Bike - Thru-Axle Disc Brake, Lightweight Touring with Multiple Rack Mounts
$6,444.00
Variable Frequency Drive Power Board ZPOW-591 for ACS880
$2,200.00
Professional Sketching Eraser Kit - Blending Stumps, Sponges, and Paper Tortillons for Highlight & Shadow Correction
$3.90
Weighted Water Bag with Handle, Thickened PV Mesh Gravity Ballast for Banner Stand Fixation (8KG)
$35.10
Ultra-Fine Purification Lint-Free Cloth Cleaning Cloth Lens Wipe High Quality 0730 Water-Absorbing Dust Removal UV Nozzle 100 Sheets
$96.00
Wen Zhengming Small Regular Script Calligraphy Cards: Li Sao Jing, Thousand Character Classic, Qin Fu, Cao Tang Shi Zhi, Qing Jing Jing, Record of the Drunken Pavilion, Red Cliff Ode
$59.00
Zhizhi Manshu Zhao Mengfu Small Regular Script Collection of Ancient Classics (Vol. 1) - Calligraphy Copybook, Brush Writing Cards, Foldable Practice Cards
$49.00
Language of Drums Motion Path Set - Essential Creativity and Rhythm Teaching Material for Drum Kits and Jazz Drums
$59.14
onlycook Sink Drain Basket, Faucet-Mounted Food Residue Separator and Washing Strainer - 1 Pack
$14.10
Heavy-Duty Wiper Arms and Blades for Trucks and Agricultural Vehicles - Universal Replacement Wiper Rubber Strips
$5.50
Bus Adapter FEPL-02 for ABB Variable Frequency Drive
$1,230.00
Baby National Trend Rattle Toy – Chewable Silicone, Easy-Grip Handle, Soft Sound for Early Learning
$19.90
Palace Museum Creative Stationery: Light & Shadow Graffiti Coloring Book - Exquisite DIY Children's Gift, Ancient Style Watercolor Set for Boys and Girls, Early Learning Art Toy
$29.70
Dongyi Study Room Antique Brass Water Pot, Brush Washer Basin, and Small Spoon Set for Calligraphy (3-Piece)
$33.10
![[Deposit Only] Slightly Round Mid-Heel Shoes – Matte Lambskin Puff Lolita Bow Pumps](https://www.gosteppe.com/cache/small/product/269338/legacy-main-1108a4ac9d29ca837505d228.webp)
[Deposit Only] Slightly Round Mid-Heel Shoes – Matte Lambskin Puff Lolita Bow Pumps
$38.00
Chunfei Grocery Store Yunan GR02 Gravel Bike with Thru-Axle Disc Brakes, Lightweight Touring Setup with Multiple Rack Mounts
$8,934.00
5A Natural Madagascar Rose Quartz Loose Beads, Pink Crystal Rhodonite Single Beads for DIY Jewelry Making Accessories
$0.70
Mini Portable Sketchbook - Blank Pocket Notebook for Doodling, Sketching, Watercolor, Acrylic, and Marker Art - Square Hand-Drawn Journal
$5.53
![[Youxin Electronics] GP2Y0E03 Infrared Distance Sensor Module 4-50cm Range](https://www.gosteppe.com/cache/medium/product/74667/legacy-main-4da8cadc5fc82afe91b124e3.webp)
![[Trial Pack] Xianlang Complete Cat Treat Sticks Meal Packs Main Course Cans Freeze-Dried Cat Food Sample Snacks Gift Set](https://www.gosteppe.com/cache/medium/product/208273/legacy-main-9ec245ebf781f65a434ba854.webp)
