A
Anonymous
Apr 07, 2026
Rating: 4/5
Good Value
Works well but instructions could be clearer for beginners.
Description
Tmall 14-Year Veteran Store Risym Weixin - High-Quality Best Seller
Reviews
Attributes
| Brand | - |
| Category | Electronic Components / Maker DIY / Computer Hardware, Monitors & Peripherals |
| Origin | - |
| Model Number | AHT21B |
| Communication Protocol | I²C (Inter-Integrated Circuit) |
| Operating Voltage | 3.3V to 5V DC |
| Temperature Measurement Range | -40°C to +85°C |
| Humidity Measurement Range | 0% to 100% RH |
| Temperature Accuracy | ±0.5°C @ 25°C |
| Humidity Accuracy | ±2% RH @ 25°C |
| Response Time | 8 Seconds (Typical) |
| Pin Configuration | VCC, GND, SDA, SCL |
| Compatible Platforms | Arduino, ESP8266, ESP32, Raspberry Pi |
5 reviews
A
Anonymous
Mar 13, 2026
Rating: 3/5
Library Issues
Hardware is fine but had trouble finding a compatible Arduino library initially.
A
Anonymous
Feb 22, 2026
Rating: 5/5
Excellent Accuracy
Used this for a greenhouse monitor. Readings match my professional hygrometer.
A
Anonymous
Feb 21, 2026
Rating: 5/5
Perfect for IoT
Low power consumption and easy to integrate with ESP32.
A
Anonymous
Jan 16, 2026
Rating: 5/5
Compact Design
Fits perfectly in my small enclosure. I2C lines are stable.
5 FAQ
Q: What is the default I2C address?
A: The factory default address is 0x38.
Q: Can this measure dew point?
A: It measures temp and humidity; dew point must be calculated in code.
Q: Is this compatible with 5V logic?
A: Yes, the module operates between 3.3V and 5V.
Q: Does it require external pull-up resistors?
A: The module has built-in pull-ups, but external ones may help on long buses.
Q: Are headers pre-soldered?
A: Yes, the module comes with male headers already attached.
