7Semi TMP102 Arduino Library

Arduino driver for the TMP102 digital temperature sensor.

The TMP102 is a high-accuracy digital temperature sensor with an I²C interface designed for applications such as environmental monitoring, industrial temperature sensing, IoT devices, and thermal protection systems.

This library provides a simple interface for configuring the sensor and reading temperature values in Celsius and Fahrenheit.

Features

• Temperature measurement (°C)

• Temperature measurement (°F)

• Raw temperature register reading

• One-shot temperature conversion

• Shutdown power-saving mode

• High and low temperature threshold configuration

• Extended temperature resolution mode

Supported Platforms

• Arduino UNO / Mega

• ESP32

• Any board supporting the Wire (I²C) library

Hardware

Supported sensor:

• 7Semi Digital Temperature Sensor I2C Breakout - TMP102

Connection

The TMP102 communicates using I²C.

I²C Connection

TMP102 Pin MCU Pin Description

TMP102 Pin	MCU Pin	Description
VCC	3.3V	Sensor power
GND	GND	Ground
SCL	SCL	I²C clock
SDA	SDA	I²C data

Default sensor address:

0x48

Available addresses depending on ADD0 pin configuration:

• 0x48
• 0x49
• 0x4A
• 0x4B

Recommended I²C speed:

• 100 kHz – 400 kHz

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Installation

Arduino Library Manager

• Open Arduino IDE

• Go to Library Manager

• Search for 7Semi TMP102

• Click Install

• Manual Installation

Download this repository as ZIP

• Arduino IDE → Sketch → Include Library → Add .ZIP Library

Example

#include <7Semi_TMP102.h>

TMP102_7Semi tmp;

void setup()
{
  Serial.begin(115200);

  if(!tmp.begin())
  {
    Serial.println("TMP102 not detected");
    while(1);
  }
}

void loop()
{
  float temperature;

  if(tmp.readTemperatureC(temperature))
  {
    Serial.print("Temperature: ");
    Serial.print(temperature);
    Serial.println(" C");
  }

  delay(1000);
}

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Library Overview

Reading Temperature (Celsius)

float temp;

tmp.readTemperatureC(temp);

Serial.print("Temperature: ");
Serial.println(temp);

Returns temperature in degrees Celsius.

Reading Temperature (Fahrenheit)

float tempF;

tmp.readTemperatureF(tempF);

Serial.print("Temperature F: ");
Serial.println(tempF);

Returns temperature in degrees Fahrenheit.

Reading Raw Temperature Register

int16_t raw;

tmp.readRawTemperature(raw);

Serial.print("Raw Temperature: ");
Serial.println(raw);

Returns raw temperature register value from the sensor.

Sensor Configuration

Conversion Rate

Controls how often the sensor performs temperature conversions.

tmp.setConversionRate(TMP102_CONVERSION_RATE_4_HZ);

Available conversion rates:

TMP102_CONVERSION_RATE_0_25_HZ
TMP102_CONVERSION_RATE_1_HZ
TMP102_CONVERSION_RATE_4_HZ
TMP102_CONVERSION_RATE_8_HZ

Higher conversion rates update temperature faster but consume more power.

Shutdown Mode (Power Saving)

Shutdown mode stops continuous conversions to reduce power consumption.

tmp.setShutdown(true);

This is useful for battery-powered applications.

One-Shot Temperature Measurement

Trigger a single temperature conversion while in shutdown mode.

tmp.startOneShot();

Useful for low power periodic measurements.

Alert Configuration

The TMP102 provides a thermostat alert system.

Example:

tmp.setHighLimit(30);
tmp.setLowLimit(20);

tmp.setAlert(true, TMP102_ALERT_ACTIVE_LOW);

This configures alert thresholds and enables alert mode.

Fault Queue

Controls how many consecutive faults must occur before an alert is triggered.

tmp.setFaultQueue(TMP102_FAULT_QUEUE_4);

Available options:

TMP102_FAULT_QUEUE_1
TMP102_FAULT_QUEUE_2
TMP102_FAULT_QUEUE_4
TMP102_FAULT_QUEUE_6

This helps prevent false alert triggers.

Alert Polarity

Configures the electrical behavior of the ALERT pin.

tmp.setAlertPolarity(TMP102_ALERT_ACTIVE_HIGH);

Available options:

TMP102_ALERT_ACTIVE_LOW
TMP102_ALERT_ACTIVE_HIGH

Extended Temperature Mode

Enable extended temperature resolution.

tmp.setExtendedMode(true);

Extended mode allows the sensor to use 13-bit temperature resolution.

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Example Applications

Typical applications include:

• Environmental temperature monitoring

• Industrial temperature sensing

• IoT devices

• Thermal protection systems

• HVAC monitoring

• Data center temperature logging

• Smart home temperature sensing

License

MIT License

Author

7Semi