Adafruit APDS9999 Proximity, Lux Light & Color Sensor

Adafruit APDS9999 Proximity, Lux Light, and Color Sensor has RGB color, lux light level as well as infrared proximity.

by Tim C

published March 10, 2026, last edited April 28, 2026

posted in Adafruit Products Sensors/ Light Arduino Compatibles CircuitPython STEMMA

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Product guide

Arduino

Using the APDS9999 breakout with Arduino involves wiring up the breakout to your Arduino-compatible microcontroller, installing the Adafruit_APDS9999 library, and running the provided example code.

Wiring

Wire as shown for a 5V board like an Uno. If you are using a 3V board, like an Adafruit Feather, wire the board's 3V pin to the sensor VIN.

Here is an Adafruit Metro wired up to the sensor using the STEMMA QT connector:

Wiring illustration showing Adafruit Metro wired to the APDS9999 breakout via STEMMA QT connector to pins 5V, GND, SCL, and SDA

Board 5V to breakout VIN (red wire)
Board GND to breakout GND (black wire)
Board SCL to breakout SCL (yellow wire)
Board SDA to breakout SDA (blue wire)

Here is an Adafruit Metro wired up using a solderless breadboard:

Wiring illustration showing Adafruit Metro connected to the APDS9999 breakout via solderless breadboard connected to pins 5V, GND, SCL, and SDA

Board 5V to breakout VIN (red wire)
Board GND to breakout GND (black wire)
Board SCL to breakout SCL (yellow wire)
Board SDA to breakout SDA (blue wire)

Library Installation

You can install the Adafruit_APDS9999 library for Arduino using the Library Manager in the Arduino IDE.

Arduino IDE showing the tools menu open with Manage Libraries highlighted

Click the Manage Libraries ... menu item, search for Adafruit_APDS9999, and select the Adafruit_APDS9999 library:

Arduino IDE library manager open with "Adafruit_APDS9999" in the search box and library in the results list.

If asked about dependencies, click "Install all".

Arduino IDE pop up window asking to install dependencies for the APDS9999 driver

If the "Dependencies" window does not come up, then you already have the dependencies installed.

If the dependencies are already installed, you must make sure you update them through the Arduino Library Manager before loading the example!

Example Code

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/*
 * Simple color sensor example for APDS-9999
 */

#include "Adafruit_APDS9999.h"

Adafruit_APDS9999 apds;

void setup() {
  Serial.begin(115200);
  while (!Serial)
    delay(10);

  if (!apds.begin()) {
    Serial.println("Failed to find APDS-9999");
    while (1)
      delay(10);
  }

  apds.enableLightSensor(true);
  apds.setRGBMode(true);
  Serial.println("APDS-9999 Color Sensor");
}

void loop() {
  uint32_t r, g, b, ir;

  if (apds.getRGBIRData(&r, &g, &b, &ir)) {
    Serial.print("R:");
    Serial.print(r);
    Serial.print(" G:");
    Serial.print(g);
    Serial.print(" B:");
    Serial.print(b);
    Serial.print(" IR:");
    Serial.print(ir);
    Serial.print(" Lux:");
    Serial.println(apds.calculateLux(g));
  }

  delay(100);
}

/*
 * Simple color sensor example for APDS-9999
 */

#include "Adafruit_APDS9999.h"

Adafruit_APDS9999 apds;

void setup() {
  Serial.begin(115200);
  while (!Serial)
    delay(10);

  if (!apds.begin()) {
    Serial.println("Failed to find APDS-9999");
    while (1)
      delay(10);
  }

  apds.enableLightSensor(true);
  apds.setRGBMode(true);
  Serial.println("APDS-9999 Color Sensor");
}

void loop() {
  uint32_t r, g, b, ir;

  if (apds.getRGBIRData(&r, &g, &b, &ir)) {
    Serial.print("R:");
    Serial.print(r);
    Serial.print(" G:");
    Serial.print(g);
    Serial.print(" B:");
    Serial.print(b);
    Serial.print(" IR:");
    Serial.print(ir);
    Serial.print(" Lux:");
    Serial.println(apds.calculateLux(g));
  }

  delay(100);
}

View on GitHub

Upload the sketch to your board and open up the Serial Monitor (Tools -> Serial Monitor) at 115200 baud. You'll see the APDS9999 recognized over I2C. Then, the RGB, IR, and calculated lux values will be printed out to the Serial Monitor.