보드 1개에 온도, 습도, 기압을 측정하는 3개의 센서가 모두 있는 모듈 입니다.

HTU21D company based in France Humirel humidity sensor element is made of high-performance, next-generation HTU21D temperature and humidity sensors established in size and intelligence of the new standards: it is embedded in a reflow solderable Dual Flat No leads (DFN) package, a bottom surface 3x3mm, height 1.1mm. Sensor output signal digitally calibrated, standard I2C format. Diversification of output, wide operating voltage range, and has a high precision temperature and humidity accuracy. HTU21 series modules are designed for low-power small size application design, with good quality, fast response, anti-interference ability and cost advantages, small size (3x3mm), very low power consumption
Sensor Important parameters:
Supply voltage: 1.5V-3.6
Humidity measuring range: 0-100% RH
Temperature measurement range: -40 ℃ -105 ℃
Maximum power consumption: 2.7uW
Of communication: I2C
Accuracy range humidity (10% RH to 95% RH): HTU21D ± 2% RH
Humidity Hysteresis: ± 1% RH
Measuring time: 50ms
Annual shift: -0.5% RH / year
Response time: 5 s
SHT21 SHT20 SHT11 SHT10 have a relatively smaller volume. Meanwhile HTU21D Switzerland can SHT20, SHT21 full compatibility can be achieved Pin to Pin Pin on hardware, without modifying the circuit board. Software programs and also Switzerland SHT20, SHT21 same can be achieved compatible replacement, without making any changes. Meanwhile HTU21D than Switzerland SHT20, SHT21 has a good price advantage, very cost-effective.
==============================================
BMP180 is a high precision, small size, ultra-low power pressure sensor can be used in mobile devices of its outstanding performance, the lowest absolute accuracy can be achieved 0.03hPa, and low power consumption, only 3μABMP180 uses a powerful 8-pin ceramic leadless chip carrier (LCC) ultra-thin package, can be directly connected with a variety of microprocessor via I2C bus
===============================================
ROHM chip using original BH1750FVI
Power supply: 3-5v
Light range: 0-65535 lx
Sensors built 16bitAD converter
Direct digital output, omit the complex calculations omit the calibration
Does not distinguish between ambient light
Spectral characteristics close to visual sensitivity
Available for a wide range of precision measuring brightness 1 lux
Standard NXP IIC communication protocol
Internal module includes a communication level conversion, and directly connected to 5v microcontroller io