The digital SHT2x humidity sensor series is used in high volumes in a wide variety of applications and has today become the de facto industry standard. The SHT2x series consists of a low-cost version with the SHT20 humidity sensor, a standard version with the SHT21 humidity sensor, and a high-end version with the SHT25 humidity sensor. The open cavity mold package – which encapsulates the complete chip except for the humidity sensor area – protects the capacitive humidity sensor against external impact and facilitates excellent long-term stability. The SHT2x sensors are available both in large and small volumes.
the SHT2x provides calibrated, linearized sensor signals in digital, I2C format. The SHT2x humidity sensor series contains a capacitive-type humidity sensor, a band-gap temperature sensor, and specialized analog and digital integrated circuits – all on a single CMOSens® chip. This yields superior sensor performance in terms of accuracy and stability as well as minimal power consumption.
Every sensor is individually calibrated and tested. Lot identification is printed on the sensor and an electronic identification code is stored on the chip – which can be read out on command. Furthermore, the resolution of the SHT2x humidity sensor can be changed on command (8/12 bit up to 12/14 bit for RH/T) and a checksum helps to improve communication reliability.
Schematics
espruino and sht21
Code
I2C1.setup({scl:B6,sda:B7});
var sht = require("SHT2x").connect(I2C1);
console.log('Temperature:', sht.readTemperature());
console.log('Humidity:', sht.readHumidity());
Output
Temperature: 28.25785888671
Humidity: 37.98345947265
Links
https://www.espruino.com/SHT2x
SHT21 Digital Humidity And Temperature Sensor Module