SHT20资料下载：https://pan.baidu.com/s/1HrQkwECvGgQSHvt_RNdLdA
HTU21D资料下载：https://pan.baidu.com/s/1bq5nrav
SHT21模块和HTU21D模块可直接替代SI7021模块，精度一致。
温湿度模块
GY21-SI7021-5V 温湿度传感器
模块型号：GY21-SHT21 GY-HTU21D
使用芯片：SHT21 HTU21D
供电电源：3-5v （带电平转换功能）
模块尺寸：10mm*12mm
重量：2g
提供ardhino测试代码：
Features
Precision Relative Humidity Sensor
± 3百 RH (max), 0–80百 RH
High Accuracy Temperature Sensor
±0.4 °C (max), –10 to 85 °C
0 to 100百 RH operating range
Up to –40 to +125 °C operating range
Wide operating voltage (1.9 to 3.6 V)
Low Power Consumption 150 μA active current
60 nA standby current
Factory-calibrated
I2C Interface
Integrated on-chip heater
3x3 mm DFN Package
Excellent long term stability
Optional factory-installed cover
Low-profile
Protection during reflow
Excludes liquids and particulates
Applications
HVAC/R
Thermostats/humidistats
Respiratory therapy
White goods
Indoor weather stations
Micro-environments/data centers
Automotive climate control and defogging
Asset and goods tracking
Mobile phones and tablets
The Si7021 I2C Humidity and Temperature Sensor is a monolithic CMOS IC
integrating humidity and temperature sensor elements, an analog-to-digital
converter, signal processing, calibration data, and an I2C Interface. The patented
use of industry-standard, low-K polymeric dielectrics for sensing humidity enables
the construction of low-power, monolithic CMOS Sensor ICs with low drift and
hysteresis, and excellent long term stability.
The humidity and temperature sensors are factory-calibrated and the calibration
data is stored in the on-chip non-volatile memory. This ensures that the sensors
are fully interchangeable, with no recalibration or software changes required.
The Si7021 is available in a 3x3 mm DFN package and is reflow solderable. It can
be used as a hardware- and software-compatible drop-in upgrade for existing RH/
temperature sensors in 3x3 mm DFN-6 packages, featuring precision sensing
over a wider range and lower power consumption. The optional factory-installed
cover offers a low profile, convenient means of protecting the sensor during
assembly (e.g., reflow soldering) and throughout the life of the product, excluding
liquids (hydrophobic/oleophobic) and particulates.
The Si7021 offers an accurate, low-power, factory-calibrated digital solution ideal
for measuring humidity, dew-point, and temperature, in applications ranging from
HVAC/R and asset tracking to industrial and consumer platforms.
