Introduction: Particle Photon - TCN75A 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.

TCN75A is a two-wire serial temperature sensor incorporated with temperature-to-digital converter. It is incorporated with user programmable registers that provide flexibility for temperature-sensing applications. The register settings allow users to configure power saving mode, shutdown mode, one shot mode etc.The sensor has an i2c compatible serial interface which can facilitate connection of upto eight devices in a single serial bus. Here is its demonstration with particle photon.

Step 1: What You Need...!!

Step 2: Connections:

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 TCN75A sensor and the other end to the I2C shield.

Connections are shown in the picture above.

Step 3: Code:

The particle code for TCN75A 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.

// TCN75A

// This code is designed to work with the TCN75A_I2CS I2C Mini Module



// TCN75A 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", "TCN75A");

Particle.variable("cTemp", cTemp);

// Initialise I2C communication as Master


// Initialise serial communication, set baud rate = 9600


// Start I2C transmission


// Select configuration register


// 12-bit ADC resolution


// Stop I2C transmission




void loop()


unsigned int data[2];

// Start I2C transmission


// Select data register


// Stop I2C transmission


// Request 2 bytes 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] & 0xF0)) / 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:

TCN75A is a temperature sensor that can be employed in personal computers and servers.It can also be deployed in entertainment systems,office equipments, hars disk drives and other PC peripherals.This sensor also find its application in data communication equipment.