Adafruit VCNL4020 Proximity and Light Sensor

Proximity and lux measurement over I2C

by Liz Clark

published November 06, 2023, last edited July 08, 2025
last major update March 08, 2024

posted in Adafruit Products Sensors/ Light Sensors/ Proximity Arduino Compatibles CircuitPython

Beginner

Product guide

Overview

The VCNL4020 is a handy two-in-one sensor, with a proximity sensor that works from 0 to 200mm (about 7.5 inches) and a light sensor with a range of 0.26 to 16,000 lux.

We've all been there. That thing is close but how close? When you need to measure a small distance with reasonable accuracy, such as the rough height of a particularly calm bumble bee, the VCNL4020 Proximity Sensor from Vishay can do that for you. If perchance you also needed to measure the amount of light at the same time, perhaps to let the bee to know if it's time for bed, you're in luck! The VCNL4020 can do that too (bumble bee not included, we tried putting it in the anti-static bag but it started buzzing in a threatening manner).

This sensor is similar to the VCNL4040 but with a wider light sensor range, up to 16000 lux!

As with all of our new I2C sensors, we've taken the VCNL4020 and put it onto a breakout PCB along with support circuitry to let you use this little wonder with 3.3V (Feather/Raspberry Pi) or 5V (Arduino/ Metro328) logic levels. Since it speaks I2C, you can easily connect it up with two wires (plus power and ground!). We've even included SparkFun qwiic compatible STEMMA QT connectors for the I2C bus so you don't even need to solder! Just wire up to your favorite micro and you can use our Arduino drivers to easily interface with the VCNL4020 and make approximate approximations of proximity in no time!

The VCNL4020 comes with a variety of knobs you can tweak such as how many samples per second (a.k.a the integration time between measurements) - more samples per second means faster results but not as good at measuring low level light. With 16-bit light level reports, and 0.25 lux per bit, you can measure from 0.25 to 16,000 lux! And various averaging filters can do your low-pass filtering for you so you get less spiky results. However, there are no other sensitivity/integration time controls.

Page last edited March 08, 2024

Text editor powered by tinymce.

Pinouts

The default I2C address is 0x13.

Power Pins

VIN - this is the power pin. To power the board, give it the same power as the logic level of your microcontroller - e.g. for a 5V micro like Arduino, use 5V
3Vo - this is the 3.3V output from the voltage regulator, you can grab up to 100mA from this if you like
GND - common ground for power and logic

I2C Logic Pins

SCL - I2C clock pin, connect to your microcontroller's I2C clock line. This pin can use 3-5V logic, and there's a 10K pullup on this pin.
SDA - I2C data pin, connect to your microcontroller's I2C data line. This pin can use 3-5V logic, and there's a 10K pullup on this pin.
STEMMA QT - These connectors allow you to connectors to dev boards with STEMMA QT (qwiic) connectors or to other things with various associated accessories

Other Pins

INT - This is the interrupt pin. You can setup the VCNL4020 to pull this low when certain conditions are met such as proximity or lux level thresholds being crossed.
CATH - At the top of the board, to the right of the VCNL4020 label on the silk, is the IR LED cathode pin. The IR LED cathode needs no external connection since the necessary connections to the driver are done internally.

Power LED and LED Jumper

Power LED - In the upper left corner, above the STEMMA connector, on the front of the board, is the power LED, labeled on. It is a green LED.
LED jumper - This jumper is located on the front of the board, to the right of the power LED. Cut the trace on this jumper to cut power to the "on" LED.

Page last edited March 08, 2024

Text editor powered by tinymce.

CircuitPython and Python

It's easy to use the VCNL4020 with Python or CircuitPython, and the Adafruit_CircuitPython_VCNL4020 module. This module allows you to easily write Python code to read proximity and lux data.

You can use this driver with any CircuitPython microcontroller board or with a computer that has GPIO and Python thanks to Adafruit_Blinka, our CircuitPython-for-Python compatibility library.

CircuitPython Microcontroller Wiring

First wire up the sensor to your board exactly as follows. The following is the sensor wired to a Feather RP2040 using the STEMMA connector:

Board STEMMA 3V to sensor VIN (red wire)
Board STEMMA GND to sensor GND (black wire)
Board STEMMA SCL to sensor SCL (yellow wire)
Board STEMMA SDA to sensor SDA (blue wire)

The following is the sensor wired to a Feather RP2040 using a solderless breadboard:

Board 3V to sensor VIN (red wire)
Board GND to sensor GND (black wire)
Board SCL to sensor SCL (yellow wire)
Board SDA to sensor SDA (blue wire)

Python Computer Wiring

Since there are dozens of Linux computers/boards you can use, we will show wiring for Raspberry Pi. For other platforms, please visit the guide for CircuitPython on Linux to see whether your platform is supported.

Here's the Raspberry Pi wired with I2C using the STEMMA connector:

Pi 3V to sensor VIN (red wire)
Pi GND to sensor GND (black wire)
Pi SCL to sensor SCL (yellow wire)
Pi SDA to sensor SDA (blue wire)

Here's the Raspberry Pi wired with I2C using a solderless breadboard:

Pi 3V to sensor VIN (red wire)
Pi GND to sensor GND (black wire)
Pi SCL to sensor SCL (yellow wire)
Pi SDA to sensor SDA (blue wire)

Python Installation of VCNL4020 Library

You'll need to install the Adafruit_Blinka library that provides the CircuitPython support in Python. This may also require enabling I2C on your platform and verifying you are running Python 3. Since each platform is a little different, and Linux changes often, please visit the CircuitPython on Linux guide to get your computer ready!

Once that's done, from your command line run the following command:

pip3 install adafruit-circuitpython-vcnl4020

If your default Python is version 3 you may need to run 'pip' instead. Just make sure you aren't trying to use CircuitPython on Python 2.x, it isn't supported!

CircuitPython Usage

To use with CircuitPython, you need to first install the Adafruit_CircuitPython_VCNL4020 library, and its dependencies, into the lib folder on your CIRCUITPY drive. Then you need to update code.py with the example script.

Thankfully, we can do this in one go. In the example below, click the Download Project Bundle button below to download the necessary libraries and the code.py file in a zip file. Extract the contents of the zip file, and copy the entire lib folder and the code.py file to your CIRCUITPY drive.

Your CIRCUITPY/lib folder should contain the following folders and file:

adafruit_bus_device/
adafruit_register/
adafruit_vcnl4020.mpy

adafruit_products_vcnl4040_vcnl4040_simpletest.py.png

Python Usage

Once you have the library pip3 installed on your computer, copy or download the following example to your computer, and run the following, replacing code.py with whatever you named the file:

python3 code.py

Example Code

If running CircuitPython: Once everything is saved to the CIRCUITPY drive, connect to the serial console to see the data printed out!

If running Python: The console output will appear wherever you are running Python.

Download Project Bundle

Copy Code

# SPDX-FileCopyrightText: 2023 Liz Clark for Adafruit Industries
# SPDX-License-Identifier: MIT

# Simple demo to read ambient light/lux
# and proximity data from VCNL4020 over I2C

import time

import board

import adafruit_vcnl4020

i2c = board.I2C()

# Initialize VCNL4020
sensor = adafruit_vcnl4020.Adafruit_VCNL4020(i2c)

while True:
    print(f"Proximity is: {sensor.proximity}")
    print(f"Ambient is: {sensor.lux}")
    # uncomment print statement below to log to Mu plotter
    # print((sensor.proximity, sensor.lux,))
    time.sleep(0.1)

# SPDX-FileCopyrightText: 2023 Liz Clark for Adafruit Industries
# SPDX-License-Identifier: MIT

# Simple demo to read ambient light/lux
# and proximity data from VCNL4020 over I2C

import time

import board

import adafruit_vcnl4020

i2c = board.I2C()

# Initialize VCNL4020
sensor = adafruit_vcnl4020.Adafruit_VCNL4020(i2c)

while True:
    print(f"Proximity is: {sensor.proximity}")
    print(f"Ambient is: {sensor.lux}")
    # uncomment print statement below to log to Mu plotter
    # print((sensor.proximity, sensor.lux,))
    time.sleep(0.1)

First, the sensor is instantiated over I2C. Then, in the loop, the proximity and lux readings are printed to the serial monitor. You'll see these readings change depending on the proximity of objects in front of the sensor and the amount of ambient light that the sensor is exposed to.

Page last edited March 08, 2024

Text editor powered by tinymce.

Arduino

Using the VCNL4020 breakout with Arduino involves wiring up the breakout to your Arduino-compatible microcontroller, installing the Adafruit_VCNL4020 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:

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

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

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

Library Installation

You can install the Adafruit_VCNL4020 library for Arduino using the Library Manager in the Arduino IDE.

Click the Manage Libraries ... menu item, search for Adafruit_VCNL4020, and select the Adafruit VCNL4020 library:

If asked about dependencies, click "Install all".

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!

Full Test Example

Download File

Copy Code

#include <Wire.h>
#include "Adafruit_VCNL4020.h"

Adafruit_VCNL4020 vcnl4020;

void setup() {
  Serial.begin(115200);
  while (!Serial) delay(10); // wait for serial port to start.
  
  Serial.println("Adafruit VCNL4020 Library Test Sketch");

  // Initialize sensor
  if (!vcnl4020.begin(&Wire)) {
    Serial.println("Failed to initialize VCNL4020!");
    while (1);
  }
  Serial.println("VCNL4020 initialized.");

  // Verify product ID & revision
  Serial.print("VCNL4020 Product ID & Revision (should be 0x21): ");
  Serial.println(vcnl4020.getProdRevision(), HEX);

  // To set up all the configuration, first disable everything
  vcnl4020.enable(false /* ALS Enable */, false /* Proximity Enable */, false /* Self-Timed Enable */);
  vcnl4020.setOnDemand(false /* ALS on demand read */, false /* Prox on demand read */);  

  // Try different proximity rates, faster measurements use more power of course!
  // Can also try: PROX_RATE_1_95_PER_S, PROX_RATE_3_9_PER_S, PROX_RATE_7_8_PER_S, 
  // PROX_RATE_16_6_PER_S, PROX_RATE_31_2_PER_S, PROX_RATE_62_5_PER_S, 
  // PROX_RATE_125_PER_S, PROX_RATE_250_PER_S
  vcnl4020.setProxRate(PROX_RATE_16_6_PER_S);
  Serial.print("Proximity Rate: ");
  switch (vcnl4020.getProxRate()) {
    case PROX_RATE_1_95_PER_S: Serial.println("1.95 measurements/s"); break;
    case PROX_RATE_3_9_PER_S: Serial.println("3.9 measurements/s"); break;
    case PROX_RATE_7_8_PER_S: Serial.println("7.8 measurements/s"); break;
    case PROX_RATE_16_6_PER_S: Serial.println("16.6 measurements/s"); break;
    case PROX_RATE_31_2_PER_S: Serial.println("31.2 measurements/s"); break;
    case PROX_RATE_62_5_PER_S: Serial.println("62.5 measurements/s"); break;
    case PROX_RATE_125_PER_S: Serial.println("125 measurements/s"); break;
    case PROX_RATE_250_PER_S: Serial.println("250 measurements/s"); break;
  }
  
  // Test LED Current (Valid range: 0-200 mA), higher currents require
  // more power but will let you detect farther.
  vcnl4020.setProxLEDmA(200);
  Serial.print("Proximity LED Current (mA): ");
  Serial.println(vcnl4020.getProxLEDmA());


  // Test Ambient Rate
  // Can also try: AMBIENT_RATE_1_SPS, AMBIENT_RATE_2_SPS, AMBIENT_RATE_3_SPS, 
  // AMBIENT_RATE_4_SPS, AMBIENT_RATE_5_SPS, AMBIENT_RATE_6_SPS, AMBIENT_RATE_8_SPS, 
  // AMBIENT_RATE_10_SPS
  vcnl4020.setAmbientRate(AMBIENT_RATE_10_SPS); 
  Serial.print("Ambient Rate: ");
  switch (vcnl4020.getAmbientRate()) {
    case AMBIENT_RATE_1_SPS: Serial.println("1 samples/s"); break;
    case AMBIENT_RATE_2_SPS: Serial.println("2 samples/s"); break;
    case AMBIENT_RATE_3_SPS: Serial.println("3 samples/s"); break;
    case AMBIENT_RATE_4_SPS: Serial.println("4 samples/s"); break;
    case AMBIENT_RATE_5_SPS: Serial.println("5 samples/s"); break;
    case AMBIENT_RATE_6_SPS: Serial.println("6 samples/s"); break;
    case AMBIENT_RATE_8_SPS: Serial.println("8 samples/s"); break;
    case AMBIENT_RATE_10_SPS: Serial.println("10 samples/s"); break;
  }

  // Test Ambient Averaging
  // Can also try: AVG_1_SAMPLES, AVG_2_SAMPLES, AVG_4_SAMPLES, 
  // AVG_8_SAMPLES, AVG_16_SAMPLES, AVG_32_SAMPLES, AVG_64_SAMPLES, 
  // AVG_128_SAMPLES

  vcnl4020.setAmbientAveraging(AVG_1_SAMPLES); 
  Serial.print("Ambient Averaging: ");
  switch (vcnl4020.getAmbientAveraging()) {
    case AVG_1_SAMPLES: Serial.println("1 sample"); break;
    case AVG_2_SAMPLES: Serial.println("2 samples"); break;
    case AVG_4_SAMPLES: Serial.println("4 samples"); break;
    case AVG_8_SAMPLES: Serial.println("8 samples"); break;
    case AVG_16_SAMPLES: Serial.println("16 samples"); break;
    case AVG_32_SAMPLES: Serial.println("32 samples"); break;
    case AVG_64_SAMPLES: Serial.println("64 samples"); break;
    case AVG_128_SAMPLES: Serial.println("128 samples"); break;
  }

  // Setup IRQ pin output when proximity data is ready
  vcnl4020.setInterruptConfig(
    true /* Proximity Ready */, 
    false /* ALS Ready */, 
    false /* Threshold */, 
    false /* true = Threshold ALS, false = Threshold Proximity */, 
    INT_COUNT_1 /* how many values before the INT fires */
  );
  
  // The proximity measurement is using a square IR signal as 
  // measurement signal. Four different values are
  // possible: PROX_FREQ_390_625_KHZ, PROX_FREQ_781_25_KHZ, 
  // PROX_FREQ_1_5625_MHZ, PROX_FREQ_3_125_MHZ
  vcnl4020.setProxFrequency(PROX_FREQ_390_625_KHZ); 
  Serial.print("Proximity Frequency: ");
  switch (vcnl4020.getProxFrequency()) {
    case PROX_FREQ_390_625_KHZ: Serial.println("390.625 KHz"); break;
    case PROX_FREQ_781_25_KHZ: Serial.println("781.25 KHz"); break;
    case PROX_FREQ_1_5625_MHZ: Serial.println("1.5625 MHz"); break;
    case PROX_FREQ_3_125_MHZ: Serial.println("3.125 MHz"); break;
  }

  
  // finally, we can set up all the sensors we want to use. for example:
  // enable light sensor and proximity sensor, we will also use 'self timed' mode, which means 
  // measurements are taken repeatedly for us and we dont have to do an 'on demand' measurement
  // request (simpler for getting started)
  vcnl4020.enable(true /* ALS Enable */, true /* Proximity Enable */, true /* Self-Timed Enable */);
  // dont use on-demand, we will have continuous reads.
  vcnl4020.setOnDemand(false /* ALS on demand read */, false /* Prox on demand read */);
}

void loop() {
  if (vcnl4020.isProxReady()) {
    Serial.print("Prox: ");
    Serial.println(vcnl4020.readProximity());
    vcnl4020.clearInterrupts( // Clear Interrupts
      true /* Proximity Ready */, 
      false /* ALS Ready */, 
      false /* Threshold Low */, 
      false /* Threshold High */
    );
  }

  if (vcnl4020.isAmbientReady()) {
    Serial.print("Ambient: ");
    Serial.print(vcnl4020.readAmbient());
    Serial.print(", ");
    vcnl4020.clearInterrupts( // Clear Interrupts
      false /* Proximity Ready */, 
      true /* ALS Ready */, 
      false /* Threshold Low */, 
      false /* Threshold High */
    );
  }
}

#include <Wire.h>
#include "Adafruit_VCNL4020.h"

Adafruit_VCNL4020 vcnl4020;

void setup() {
  Serial.begin(115200);
  while (!Serial) delay(10); // wait for serial port to start.
  
  Serial.println("Adafruit VCNL4020 Library Test Sketch");

  // Initialize sensor
  if (!vcnl4020.begin(&Wire)) {
    Serial.println("Failed to initialize VCNL4020!");
    while (1);
  }
  Serial.println("VCNL4020 initialized.");

  // Verify product ID & revision
  Serial.print("VCNL4020 Product ID & Revision (should be 0x21): ");
  Serial.println(vcnl4020.getProdRevision(), HEX);

  // To set up all the configuration, first disable everything
  vcnl4020.enable(false /* ALS Enable */, false /* Proximity Enable */, false /* Self-Timed Enable */);
  vcnl4020.setOnDemand(false /* ALS on demand read */, false /* Prox on demand read */);  

  // Try different proximity rates, faster measurements use more power of course!
  // Can also try: PROX_RATE_1_95_PER_S, PROX_RATE_3_9_PER_S, PROX_RATE_7_8_PER_S, 
  // PROX_RATE_16_6_PER_S, PROX_RATE_31_2_PER_S, PROX_RATE_62_5_PER_S, 
  // PROX_RATE_125_PER_S, PROX_RATE_250_PER_S
  vcnl4020.setProxRate(PROX_RATE_16_6_PER_S);
  Serial.print("Proximity Rate: ");
  switch (vcnl4020.getProxRate()) {
    case PROX_RATE_1_95_PER_S: Serial.println("1.95 measurements/s"); break;
    case PROX_RATE_3_9_PER_S: Serial.println("3.9 measurements/s"); break;
    case PROX_RATE_7_8_PER_S: Serial.println("7.8 measurements/s"); break;
    case PROX_RATE_16_6_PER_S: Serial.println("16.6 measurements/s"); break;
    case PROX_RATE_31_2_PER_S: Serial.println("31.2 measurements/s"); break;
    case PROX_RATE_62_5_PER_S: Serial.println("62.5 measurements/s"); break;
    case PROX_RATE_125_PER_S: Serial.println("125 measurements/s"); break;
    case PROX_RATE_250_PER_S: Serial.println("250 measurements/s"); break;
  }
  
  // Test LED Current (Valid range: 0-200 mA), higher currents require
  // more power but will let you detect farther.
  vcnl4020.setProxLEDmA(200);
  Serial.print("Proximity LED Current (mA): ");
  Serial.println(vcnl4020.getProxLEDmA());


  // Test Ambient Rate
  // Can also try: AMBIENT_RATE_1_SPS, AMBIENT_RATE_2_SPS, AMBIENT_RATE_3_SPS, 
  // AMBIENT_RATE_4_SPS, AMBIENT_RATE_5_SPS, AMBIENT_RATE_6_SPS, AMBIENT_RATE_8_SPS, 
  // AMBIENT_RATE_10_SPS
  vcnl4020.setAmbientRate(AMBIENT_RATE_10_SPS); 
  Serial.print("Ambient Rate: ");
  switch (vcnl4020.getAmbientRate()) {
    case AMBIENT_RATE_1_SPS: Serial.println("1 samples/s"); break;
    case AMBIENT_RATE_2_SPS: Serial.println("2 samples/s"); break;
    case AMBIENT_RATE_3_SPS: Serial.println("3 samples/s"); break;
    case AMBIENT_RATE_4_SPS: Serial.println("4 samples/s"); break;
    case AMBIENT_RATE_5_SPS: Serial.println("5 samples/s"); break;
    case AMBIENT_RATE_6_SPS: Serial.println("6 samples/s"); break;
    case AMBIENT_RATE_8_SPS: Serial.println("8 samples/s"); break;
    case AMBIENT_RATE_10_SPS: Serial.println("10 samples/s"); break;
  }

  // Test Ambient Averaging
  // Can also try: AVG_1_SAMPLES, AVG_2_SAMPLES, AVG_4_SAMPLES, 
  // AVG_8_SAMPLES, AVG_16_SAMPLES, AVG_32_SAMPLES, AVG_64_SAMPLES, 
  // AVG_128_SAMPLES

  vcnl4020.setAmbientAveraging(AVG_1_SAMPLES); 
  Serial.print("Ambient Averaging: ");
  switch (vcnl4020.getAmbientAveraging()) {
    case AVG_1_SAMPLES: Serial.println("1 sample"); break;
    case AVG_2_SAMPLES: Serial.println("2 samples"); break;
    case AVG_4_SAMPLES: Serial.println("4 samples"); break;
    case AVG_8_SAMPLES: Serial.println("8 samples"); break;
    case AVG_16_SAMPLES: Serial.println("16 samples"); break;
    case AVG_32_SAMPLES: Serial.println("32 samples"); break;
    case AVG_64_SAMPLES: Serial.println("64 samples"); break;
    case AVG_128_SAMPLES: Serial.println("128 samples"); break;
  }

  // Setup IRQ pin output when proximity data is ready
  vcnl4020.setInterruptConfig(
    true /* Proximity Ready */, 
    false /* ALS Ready */, 
    false /* Threshold */, 
    false /* true = Threshold ALS, false = Threshold Proximity */, 
    INT_COUNT_1 /* how many values before the INT fires */
  );
  
  // The proximity measurement is using a square IR signal as 
  // measurement signal. Four different values are
  // possible: PROX_FREQ_390_625_KHZ, PROX_FREQ_781_25_KHZ, 
  // PROX_FREQ_1_5625_MHZ, PROX_FREQ_3_125_MHZ
  vcnl4020.setProxFrequency(PROX_FREQ_390_625_KHZ); 
  Serial.print("Proximity Frequency: ");
  switch (vcnl4020.getProxFrequency()) {
    case PROX_FREQ_390_625_KHZ: Serial.println("390.625 KHz"); break;
    case PROX_FREQ_781_25_KHZ: Serial.println("781.25 KHz"); break;
    case PROX_FREQ_1_5625_MHZ: Serial.println("1.5625 MHz"); break;
    case PROX_FREQ_3_125_MHZ: Serial.println("3.125 MHz"); break;
  }

  
  // finally, we can set up all the sensors we want to use. for example:
  // enable light sensor and proximity sensor, we will also use 'self timed' mode, which means 
  // measurements are taken repeatedly for us and we dont have to do an 'on demand' measurement
  // request (simpler for getting started)
  vcnl4020.enable(true /* ALS Enable */, true /* Proximity Enable */, true /* Self-Timed Enable */);
  // dont use on-demand, we will have continuous reads.
  vcnl4020.setOnDemand(false /* ALS on demand read */, false /* Prox on demand read */);
}

void loop() {
  if (vcnl4020.isProxReady()) {
    Serial.print("Prox: ");
    Serial.println(vcnl4020.readProximity());
    vcnl4020.clearInterrupts( // Clear Interrupts
      true /* Proximity Ready */, 
      false /* ALS Ready */, 
      false /* Threshold Low */, 
      false /* Threshold High */
    );
  }

  if (vcnl4020.isAmbientReady()) {
    Serial.print("Ambient: ");
    Serial.print(vcnl4020.readAmbient());
    Serial.print(", ");
    vcnl4020.clearInterrupts( // Clear Interrupts
      false /* Proximity Ready */, 
      true /* ALS Ready */, 
      false /* Threshold Low */, 
      false /* Threshold High */
    );
  }
}

Upload the sketch to your board and open up the Serial Monitor (Tools -> Serial Monitor) at 115200 baud. You'll see the VCNL4020 recognized over I2C. Then, proximity and ambient light readings will be printed to the Serial Monitor. You'll see these values changes as you affect your proximity to the sensor and the ambient light around the sensor.

Plotter Example

Download File

Copy Code

#include <Wire.h>
#include "Adafruit_VCNL4020.h"

// This example is pared down specifically to make it easier to test using the serial plotter

Adafruit_VCNL4020 vcnl4020;

void setup() {
  Serial.begin(115200);
  while (!Serial) delay(10); // wait for serial port to start.
  
  Serial.println("Adafruit VCNL4020 Library Test Sketch");

  // Initialize sensor
  if (!vcnl4020.begin(&Wire)) {
    Serial.println("Failed to initialize VCNL4020!");
    while (1);
  }
  Serial.println("VCNL4020 initialized.");

  // To set up all the configuration, first disable everything
  vcnl4020.enable(false /* ALS Enable */, false /* Proximity Enable */, false /* Self-Timed Enable */);
  vcnl4020.setOnDemand(false /* ALS on demand read */, false /* Prox on demand read */);  

  // Try different proximity rates, faster measurements use more power of course!
  vcnl4020.setProxRate(PROX_RATE_250_PER_S);
  
  // Set LED Current (Valid range: 0-200 mA), higher currents require
  // more power but will let you detect farther.
  vcnl4020.setProxLEDmA(200);

  // Setup IRQ pin output when proximity data is ready
  vcnl4020.setInterruptConfig(
    true /* Proximity Ready */, 
    false /* ALS Ready */, 
    false /* Threshold */, 
    false /* true = Threshold ALS, false = Threshold Proximity */, 
    INT_COUNT_1 /* how many values before the INT fires */
  );
  
  // finally, we can set up all the sensors we want to use.
  vcnl4020.enable(false /* ALS Enable */, true /* Proximity Enable */, true /* Self-Timed Enable */);
  // dont use on-demand, we will have continuous reads.
  vcnl4020.setOnDemand(false /* ALS on demand read */, false /* Prox on demand read */);
}

void loop() {
  if (vcnl4020.isProxReady()) {
    uint16_t p = vcnl4020.readProximity();
    if (p != 0xFFFF) {  // ignore spurious readings
      Serial.print("Prox: ");
      Serial.println(p);
      
    }
    vcnl4020.clearInterrupts( // Clear Interrupts
      true /* Proximity Ready */, 
      false /* ALS Ready */, 
      false /* Threshold Low */, 
      false /* Threshold High */
    );
  }
}

#include <Wire.h>
#include "Adafruit_VCNL4020.h"

// This example is pared down specifically to make it easier to test using the serial plotter

Adafruit_VCNL4020 vcnl4020;

void setup() {
  Serial.begin(115200);
  while (!Serial) delay(10); // wait for serial port to start.
  
  Serial.println("Adafruit VCNL4020 Library Test Sketch");

  // Initialize sensor
  if (!vcnl4020.begin(&Wire)) {
    Serial.println("Failed to initialize VCNL4020!");
    while (1);
  }
  Serial.println("VCNL4020 initialized.");

  // To set up all the configuration, first disable everything
  vcnl4020.enable(false /* ALS Enable */, false /* Proximity Enable */, false /* Self-Timed Enable */);
  vcnl4020.setOnDemand(false /* ALS on demand read */, false /* Prox on demand read */);  

  // Try different proximity rates, faster measurements use more power of course!
  vcnl4020.setProxRate(PROX_RATE_250_PER_S);
  
  // Set LED Current (Valid range: 0-200 mA), higher currents require
  // more power but will let you detect farther.
  vcnl4020.setProxLEDmA(200);

  // Setup IRQ pin output when proximity data is ready
  vcnl4020.setInterruptConfig(
    true /* Proximity Ready */, 
    false /* ALS Ready */, 
    false /* Threshold */, 
    false /* true = Threshold ALS, false = Threshold Proximity */, 
    INT_COUNT_1 /* how many values before the INT fires */
  );
  
  // finally, we can set up all the sensors we want to use.
  vcnl4020.enable(false /* ALS Enable */, true /* Proximity Enable */, true /* Self-Timed Enable */);
  // dont use on-demand, we will have continuous reads.
  vcnl4020.setOnDemand(false /* ALS on demand read */, false /* Prox on demand read */);
}

void loop() {
  if (vcnl4020.isProxReady()) {
    uint16_t p = vcnl4020.readProximity();
    if (p != 0xFFFF) {  // ignore spurious readings
      Serial.print("Prox: ");
      Serial.println(p);
      
    }
    vcnl4020.clearInterrupts( // Clear Interrupts
      true /* Proximity Ready */, 
      false /* ALS Ready */, 
      false /* Threshold Low */, 
      false /* Threshold High */
    );
  }
}

This example is simpler than the full test example to specifically make it easier to test using the Serial Plotter. Upload the sketch to your board and open up the Serial Plotter (Tools -> Serial Plotter) at 115200 baud. You'll see the proximity readings from the VCNL4020 plotted over time.

Page last edited March 08, 2024

Text editor powered by tinymce.

WipperSnapper

Using the VCNL4020 with WipperSnapper needs firmware Version 77 or higher!

What is WipperSnapper

WipperSnapper is a firmware designed to turn any WiFi-capable board into an Internet-of-Things device without programming a single line of code. WipperSnapper connects to Adafruit IO, a web platform designed (by Adafruit!) to display, respond, and interact with your project's data.

Simply load the WipperSnapper firmware onto your board, add credentials, and plug it into power. Your board will automatically register itself with your Adafruit IO account.

From there, you can add components to your board such as buttons, switches, potentiometers, sensors, and more! Components are dynamically added to hardware, so you can immediately start interacting, logging, and streaming the data your projects produce without writing code.

If you've never used WipperSnapper, click below to read through the quick start guide before continuing.

Quickstart: Adafruit IO WipperSnapper

Wiring

First, wire up an VCNL4020 to your board exactly as follows. Here is an example of the VCNL4020 wired to an Adafruit ESP32 Feather V2 using I2C with a STEMMA QT cable (no soldering required)

Board 3V to sensor VIN (red wire on STEMMA QT)
Board GND to sensor GND (black wire on STEMMA QT)
Board SCL to sensor SCL (yellow wire on STEMMA QT)
Board SDA to sensor SDA (blue wire on STEMMA QT)

Usage

Connect your board to Adafruit IO Wippersnapper and navigate to the WipperSnapper board list.

On this page, select the WipperSnapper board you're using to be brought to the board's interface page.

If you do not see your board listed here - you need to connect your board to Adafruit IO first.

On the device page, quickly check that you're running the latest version of the WipperSnapper firmware.

The device tile on the left indicates the version number of the firmware running on the connected board.

If the firmware version is green with a checkmark - continue with this guide.
If the firmware version is red with an exclamation mark "!" - update to the latest WipperSnapper firmware on your board before continuing.

Next, make sure the sensor is plugged into your board and click the I2C Scan button.

You should see the VCNL4020's default I2C address of 0x13 pop-up in the I2C scan list.

I don't see the sensor's I2C address listed!

First, double-check the connection and/or wiring between the sensor and the board.

Then, reset the board and let it re-connect to Adafruit IO WipperSnapper.

With the sensor detected in an I2C scan, you're ready to add the sensor to your board.

Click the New Component button or the + button to bring up the component picker.

Adafruit IO supports a large amount of components. To quickly find your sensor, type VCNL4020 into the search bar, then select the VCNL4020 component.

On the component configuration page, the VCNL4020's sensor address should be listed along with the sensor's settings.

The Send Every option is specific to each sensor's measurements. This option will tell the Feather how often it should read from the VCNL4020 sensor and send the data to Adafruit IO. Measurements can range from every 30 seconds to every 24 hours.

For this example, set the Send Every interval to every 30 seconds.

Your device interface should now show the sensor components you created. After the interval you configured elapses, WipperSnapper will automatically read values from the sensor(s) and send them to Adafruit IO.

To view the data that has been logged from the sensor, click on the graph next to the sensor name.

Here you can see the feed history and edit things about the feed such as the name, privacy, webhooks associated with the feed and more. If you want to learn more about how feeds work, check out this page.