SHT20 Digital Temperature And Humidity Sensor

				
					#include <Wire.h>

#define SHT20_ADDR 0x40
#define TRIG_TEMP_MEAS 0xF3
#define TRIG_HUMI_MEAS 0xF5

void setup() {
  Wire.begin();
  Serial.begin(9600);
  while (!Serial); // Wait for serial port to connect
  Serial.println("SHT20 Temperature and Humidity Sensor Test");
  delay(100);
}

void loop() {
  float temp = readTemperature();
  float humi = readHumidity();
  
  Serial.print("Temperature: ");
  Serial.print(temp);
  Serial.print(" °C, Humidity: ");
  Serial.print(humi);
  Serial.println(" %RH");
  
  delay(1000);
}

float readTemperature() {
  Wire.beginTransmission(SHT20_ADDR);
  Wire.write(TRIG_TEMP_MEAS);
  Wire.endTransmission();
  
  delay(50); // Wait for measurement (≈66ms for 14-bit resolution)
  
  Wire.requestFrom(SHT20_ADDR, 3);
  while (Wire.available() < 3);
  
  uint16_t tempData = (Wire.read() << 8) | Wire.read();
  Wire.read(); // Read checksum (optional for basic use)
  
  return -46.85 + 175.72 * (tempData & 0xFFFC) / 65536.0;
}

float readHumidity() {
  Wire.beginTransmission(SHT20_ADDR);
  Wire.write(TRIG_HUMI_MEAS);
  Wire.endTransmission();
  
  delay(30); // Wait for measurement (≈22ms for 12-bit resolution)
  
  Wire.requestFrom(SHT20_ADDR, 3);
  while (Wire.available() < 3);
  
  uint16_t humiData = (Wire.read() << 8) | Wire.read();
  Wire.read(); // Read checksum (optional for basic use)
  
  float humidity = -6.0 + 125.0 * (humiData & 0xFFFC) / 65536.0;
  return constrain(humidity, 0.0, 100.0);
}