Attributes

Brand	-
Category	Robotics / STEM Teaching Tools / Sensors
Origin	-
Interface	I2C
Supply Voltage	1.5V ~ 3.6V DC
Temperature Range	-40°C to +85°C
Humidity Range	0% to 100% RH
Temperature Accuracy	±0.3°C (typical)
Humidity Accuracy	±2% RH (typical)
Response Time	5s (63% RH step)
Package Type	DFN-6
Communication Protocol	Digital I2C
Application	HVAC, Weather Stations, IoT Devices

6 reviews

Anonymous

Mar 29, 2026

Rating: 4/5

Great value, small footprint

Very compact module which fits well in tight enclosures. Setup was straightforward using standard libraries. Only giving 4 stars because the breakout board pins are a bit close together for breadboarding without adapters.

Anonymous

Mar 27, 2026

Rating: 5/5

Reliable humidity monitoring

I deployed six of these in my automated greenhouse system. They have been running for three months without drift or failure. The low power consumption is a huge plus for my battery-operated nodes.

Anonymous

Mar 25, 2026

Rating: 5/5

Best in class for the price

Compared to other DHT sensors, the HTU21D offers much better precision and reliability. Highly recommended for any serious embedded project requiring environmental data.

Anonymous

Mar 24, 2026

Rating: 5/5

Perfect for my weather station project

These sensors are incredibly accurate and easy to interface with an Arduino. The I2C communication is stable, and the readings match my calibrated reference meter almost perfectly.

Anonymous

Mar 16, 2026

Rating: 4/5

Solid performance

Works as advertised. The temperature reading is very stable. Humidity takes a few seconds to settle after a sharp change, but that is expected for this class of sensor.

Anonymous

Mar 01, 2026

Rating: 5/5

Excellent documentation support

The datasheet is clear, and finding example code for ESP32 and Raspberry Pi was effortless. The sensor responds quickly to changes in environmental conditions.

5 FAQ

Q: Is this module compatible with 5V logic microcontrollers like the Arduino Uno?

A: Yes, the module operates on 1.5V to 3.6V, but most breakout boards include a voltage regulator and level shifters, making them safe to connect directly to 5V Arduino boards. Please check your specific breakout board schematic.

Q: What is the default I2C address for this sensor?

A: The default I2C address for the HTU20D/HTU21D is typically 0x40. However, some variations may exist depending on the specific manufacturer of the breakout board.

Q: Can this sensor be used outdoors in direct rain?

A: No, the sensor element itself is not waterproof. While it can measure high humidity, it must be housed in a weatherproof enclosure with a breathable membrane to protect it from direct water contact.

Q: How often should I recalibrate this sensor?

A: Under normal operating conditions, the HTU21D maintains its calibration well for years. Recalibration is generally only necessary if the sensor has been exposed to extreme conditions beyond its specified limits.

Q: Does this come with a protective filter cap?

A: This specific listing is for the bare module or basic breakout board and does not include a separate protective filter cap. These can be purchased separately if needed for dust protection.

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