# Source: https://learn.adafruit.com/tsl2561/wiring-the-tsl2561-sensor.md

# TSL2561 Luminosity Sensor

## Wiring the TSL2561 Sensor

# Breakout Board Prep

This is an easy sensor to get started with. If you have the Breakout board version, it comes with a 6-pin header strip that you can use to plug the sensor into a breadboard or perfboard. Simply plug the header into a solderless breadboard with the long pins down and short pins up. Place the sensor on top so each pad has a header pin in it and solder the two together.

![](https://cdn-learn.adafruit.com/assets/assets/000/000/583/medium800/light_tslsolder.jpg?1396764248)

# Wiring up the sensor

Next we will connect it to our microcontroller. In this case we'll be using an Arduino but nearly any microcontroller can be used by adapting our code

- Connect the&nbsp; **VCC&nbsp;** pin to a&nbsp; **3.3V** &nbsp;or **5v** power source (Whatever the logic level of your microcontroller is!)
- Connect&nbsp; **GND** &nbsp;to the ground pin.
- Connect the&nbsp; **i2c SCL clock&nbsp;** pin to your i2c clock pin. On the classic Arduino Uno/Duemilanove/Diecimila/etc this is&nbsp; **Analog pin #5**
- Connect the&nbsp; **i2c SDA data&nbsp;** pin to your i2c data pin. On the classic Arduino Uno/Duemilanove/Diecimila/etc this is&nbsp; **Analog pin #4**

The i2c lines on most microcontrollers are fixed so you're going to have to stick with those pins.

![](https://cdn-learn.adafruit.com/assets/assets/000/036/109/medium800/light_unotsl2561.png?1475165716)

[uno + tsl2561 Fritzing diagram](https://cdn-learn.adafruit.com/assets/assets/000/036/110/original/unotsl2561.fzz?1475165730)
You don't need to connect the&nbsp; **ADDR** &nbsp;(i2c address change) or&nbsp; **INT** &nbsp;(interrupt output) pins.

The&nbsp; **ADDR** &nbsp;pin can be used if you have an i2c address conflict, to change the address. Connect it to ground to set the address to&nbsp; **0x29** , connect it to 3.3V (vcc) to se t the address to&nbsp; **0x49** &nbsp;or leave it floating (unconnected) to use address&nbsp; **0x39**.

The&nbsp; **INT&nbsp;** pin is an ouput&nbsp;_from_&nbsp;the sensor used when you have the sensor configured to signal when the light level has changed. We don't have that code written in this tutorial so you don't have to use it. If you do end up using it, use a 10K-100K pullup from&nbsp; **INT** &nbsp;to 3.3V (vcc)

- [Previous Page](https://learn.adafruit.com/tsl2561/overview.md)
- [Next Page](https://learn.adafruit.com/tsl2561/arduino-code.md)

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