Description
Reviews
| Brand | - |
| Category | Robotics / STEM Teaching Tools / Sensors |
| Origin | - |
| Model Number | AHT21B |
| Communication Interface | I2C |
| Operating Voltage | 1.8V - 3.6V DC |
| Temperature Range | -40°C to +85°C |
| Humidity Range | 0% to 100% RH |
| Temperature Accuracy | ±0.3°C |
| Humidity Accuracy | ±2% RH |
| Response Time | < 5 seconds |
| Package Type | DFN Package |
| Application | IoT, HVAC, Smart Home |
Anonymous
Mar 30, 2026
Rating: 5/5
Best in class for the price
Compared to other sensors in this price range, the AHT21 offers superior response time and accuracy. Will definitely buy more for future projects.
Anonymous
Mar 16, 2026
Rating: 5/5
Excellent anti-interference performance
I tested this in a noisy electrical environment and the readings remained stable. The strong anti-interference claim seems accurate based on my tests.
Anonymous
Mar 15, 2026
Rating: 4/5
Solid sensor module
Easy to integrate using standard libraries. The form factor is compact which helped fit it into my small enclosure. Works as advertised.
Anonymous
Mar 12, 2026
Rating: 5/5
Reliable for plant monitoring
Using three of these in my automated greenhouse system. They have been running 24/7 for a month without any drift or failures. Great value for money.
Anonymous
Mar 08, 2026
Rating: 5/5
Perfect for my weather station project
The AHT21 module works flawlessly with my ESP32 setup. The I2C communication is stable and the readings are consistent with my reference meter. Highly recommended for DIY enthusiasts.
Anonymous
Mar 07, 2026
Rating: 4/5
Good accuracy, fast shipping
Arrived quickly and well-packaged. The sensor responds very fast to changes in humidity. Only giving 4 stars because the documentation could be slightly more detailed for beginners.
Q: Is this module compatible with Arduino Uno?
A: Yes, the AHT21 uses standard I2C communication and is fully compatible with Arduino Uno. You will need to connect the SDA and SCL pins accordingly.
Q: Can this sensor be used outdoors directly?
A: The module itself is not waterproof. For outdoor use, you must house it in a breathable, weather-proof enclosure to protect the electronics while allowing air flow.
Q: What is the maximum cable length recommended for I2C connection?
A: For reliable I2C communication, we recommend keeping the cable length under 20cm. If longer distances are required, please use an I2C extender or buffer.
Q: What is the power consumption in sleep mode?
A: The AHT21 features low power consumption. In sleep mode, it draws less than 0.5µA, making it ideal for battery-powered applications.
Q: Does this come with a library for Raspberry Pi?
A: While we do not provide a proprietary library, the AHT21 is supported by many open-source Python libraries available on GitHub for Raspberry Pi.
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