Introduction: Particle Photon - ADT75 Temperature Sensor Tutorial

About: We are a group of makers. We work in IoT, IOS app, android app, embedded design, sensor design, raspberry pi, arduino, beaglebone, particle electron, particle photon, Bluetooth.

ADT75 is a highly accurate, digital temperature sensor. It comprises of a band gap temperature sensor and a 12-bit analog to digital converter for monitoring and digitizing the temperature. Its highly sensitive sensor makes it competent enough to measure the ambient temperature accurately.Here is the demonstration of using it with particle photon.

Step 1: What You Need..!!

Step 2: Connection:

Take an I2C shield for particle photon and gently push it over the pins of particle photon.

Then connect the one end of I2C cable to ADT75 sensor and the other end to the I2C shield.

Connections are shown in the picture above.

Step 3: Code:

The particle code for ADT75 can be downloaded from our github repository-DCUBE Store.

Here is the link for the same :

We have used two libraries for particle code, which are application.h and spark_wiring_i2c.h. Spark_wiring_i2c library is required to facilitate the I2C communication with the sensor.

You can also copy the code from here, it is given as follows:

// Distributed with a free-will license.

// Use it any way you want, profit or free, provided it fits in the licenses of its associated works.

// ADT75

// This code is designed to work with the ADT75_I2CS I2C Mini Module



// ADT75 I2C address is 0x48(72)

#define Addr 0x48

float cTemp = 0.0, fTemp = 0.0;

int temp = 0;

void setup()


// Set variable

Particle.variable("i2cdevice", "ADT75");

Particle.variable("cTemp", cTemp);

// Initialise I2C communication as Master


// Initialise serial communication, set baud rate = 9600




void loop()


unsigned int data[2];

// Start I2C transmission


// Select data register


// Stop I2C transmission


// Request 2 byte of data

Wire.requestFrom(Addr, 2);

// Read 2 bytes of data

// temp msb, temp lsb

if (Wire.available() == 2)


data[0] =;

data[1] =;


// Convert the data to 12 bits

temp = ((data[0] * 256) + data[1]) / 16;

if(temp > 2047)


temp -= 4096;


cTemp = temp * 0.0625;

fTemp = (cTemp * 1.8) + 32;

// Output data to dashboard

Particle.publish("Temperature in Celsius : ", String(cTemp));

Particle.publish("Temperature in Fahrenheit : ", String(fTemp));



Step 4: Applications:

ADT75 is a highly accurate, digital temperature sensor. It can be employed in a wide range of systems including environmental control systems, computer thermal monitoring etc. It can also be incorporated in industrial process controls as well as power system monitors.