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Interfacing TSL2561 Luminosity Sensor with Arduino

Table of Contents

TSL2561 Sensor Features

The TSL2561 Luminosity Sensor Breakout is a complex light sensor which has a flat response across most of the visible spectrum range.

This sensor is capable of direct I2C communication and is able to conduct specific light ranges from 0.1 – 40k+ Lux easily.

You can download the datasheet of this module here.

TSL2561 Sensor Pinout

This module has 2 pins:

  • VCC: Module power supply – 5V
  • GND: Ground 
  • SLC: I2C clock 
  • SDA: I2C data 
  • INTAdjusting I2C address 

You can see pinout of this module in the image below.

Required Materials

Hardware Components

Arduino UNO R3 × 1
TSL2561 Luminosity Sensor × 1
Male Female Jumper Wire × 1

Software Apps

Arduino IDE

Interfacing TSL2561 Sensor with Arduino

Step 1: Circuit

Connect the module to the Arduino according to the following image.

Step 2: Code

Install following library on your Arduino board.


If you need more help with installing a library on Arduino, read this tutorial: How to Install an Arduino Library

Upload the following code to your Arduino.

modified on Sep 14, 2020
Modified by MohammedDamirchi from 

#include <Wire.h>
#include "TSL2561.h"

// Example for demonstrating the TSL2561 library - public domain!

// connect SCL to analog 5
// connect SDA to analog 4
// connect VDD to 3.3V DC
// connect GROUND to common ground
// ADDR can be connected to ground, or vdd or left floating to change the i2c address

// The address will be different depending on whether you let
// the ADDR pin float (addr 0x39), or tie it to ground or vcc. In those cases
// use TSL2561_ADDR_LOW (0x29) or TSL2561_ADDR_HIGH (0x49) respectively
TSL2561 tsl(TSL2561_ADDR_FLOAT);

void setup(void) {

  if (tsl.begin()) {
    Serial.println("Found sensor");
  } else {
    Serial.println("No sensor?");
    while (1);

  // You can change the gain on the fly, to adapt to brighter/dimmer light situations
  //tsl.setGain(TSL2561_GAIN_0X);         // set no gain (for bright situtations)
  tsl.setGain(TSL2561_GAIN_16X);      // set 16x gain (for dim situations)

  // Changing the integration time gives you a longer time over which to sense light
  // longer timelines are slower, but are good in very low light situtations!
  tsl.setTiming(TSL2561_INTEGRATIONTIME_13MS);  // shortest integration time (bright light)
  //tsl.setTiming(TSL2561_INTEGRATIONTIME_101MS);  // medium integration time (medium light)
  //tsl.setTiming(TSL2561_INTEGRATIONTIME_402MS);  // longest integration time (dim light)

  // Now we're ready to get readings!

void loop(void) {
  // Simple data read example. Just read the infrared, fullspecrtrum diode
  // or 'visible' (difference between the two) channels.
  // This can take 13-402 milliseconds! Uncomment whichever of the following you want to read
  uint16_t x = tsl.getLuminosity(TSL2561_VISIBLE);
  //uint16_t x = tsl.getLuminosity(TSL2561_FULLSPECTRUM);
  //uint16_t x = tsl.getLuminosity(TSL2561_INFRARED);

  Serial.print(x, DEC);
  // More advanced data read example. Read 32 bits with top 16 bits IR, bottom 16 bits full spectrum
  // That way you can do whatever math and comparisons you want!
  uint32_t lum = tsl.getFullLuminosity();
  uint16_t ir, full;
  ir = lum >> 16;
  full = lum & 0xFFFF;
  Serial.print("IR: "); Serial.print(ir);   Serial.print("\t\t");
  Serial.print("Full: "); Serial.print(full);   Serial.print("\t");
  Serial.print("Visible: "); Serial.print(full - ir);   Serial.print("\t");
After running the code, you will see the following image in the serial output.

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