#include <application.h>
#include <spark_wiring_i2c.h>
// SHT31 I2C address is 0x44(68)
#define Addr 0x44
int temp = 0;
double cTemp = 0.0, fTemp = 0.0, humidity = 0.0;
void setup()
{
// Set variable
Particle.variable("i2cdevice", "SHT31");
Particle.variable("cTemp", cTemp);
Particle.variable("humidity", humidity);
// Initialise I2C communication as MASTER
Wire.begin();
// Initialise serial communication, set baud rate = 9600
Serial.begin(9600);
delay(300);
}
void loop()
{
unsigned int data[6];
// Start I2C Transmission
Wire.beginTransmission(Addr);
// Send 16-bit command byte
Wire.write(0x2C);
Wire.write(0x06);
// Stop I2C transmission
Wire.endTransmission();
delay(300);
// Start I2C Transmission
Wire.beginTransmission(Addr);
// Select data register
Wire.write(0x00);
// Stop I2C Transmission
Wire.endTransmission();
// Request 6 bytes of data from the device
Wire.requestFrom(Addr, 6);
// Read 6 bytes of data
// temp msb, temp lsb, crc, hum msb, hum lsb, crc
if (Wire.available() == 6)
{
data[0] = Wire.read();
data[1] = Wire.read();
data[2] = Wire.read();
data[3] = Wire.read();
data[4] = Wire.read();
data[5] = Wire.read();
}
// Convert the data
temp = (data[0] * 256) + data[1];
cTemp = -45.0 + (175.0 * temp / 65535.0);
fTemp = (cTemp * 1.8) + 32;
humidity = 100 * ((data[3] * 256) + data[4]) / 65535.0;
// Output data to dashboard
Particle.publish("Temperature in Celsius: ", String(cTemp));
delay(1000);
Particle.publish("Temperature in Fahrenheit: ", String(fTemp));
delay(1000);
Particle.publish("Relative Humidity : ", String(humidity));
delay(1000);
}
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