VCNL4040 - Proximity and Ambient Light Sensor

The VCNL4040 combines a proximity sensor, infrared emitter, ambient light sensor, and white-light channel. The binding supports sensor power control, emitter and receiver configuration, measurements, threshold interrupts, and interrupt flags. Its fixed I2C address is 0x60.

Documentation

• VCNL4040 datasheet
• VCNL4040 application note

Wiring

VCNL4040	ESP32
VIN	3.3 V
GND	GND
SDA	GPIO21
SCL	GPIO22
INT	Any input GPIO (optional)

Configure ESP32 I2C pins before creating the device. Other targets use their board-specific I2C pins.

Usage

Configuration.SetPinFunction(21, DeviceFunction.I2C1_DATA);
Configuration.SetPinFunction(22, DeviceFunction.I2C1_CLOCK);

I2cConnectionSettings settings = new I2cConnectionSettings(1, Vcnl4040Device.DefaultI2cAddress);
using I2cDevice i2cDevice = I2cDevice.Create(settings);
using Vcnl4040Device sensor = new Vcnl4040Device(i2cDevice);

sensor.AmbientLightSensor.IntegrationTime = AlsIntegrationTime.Time160ms;
sensor.AmbientLightSensor.PowerOn = true;
sensor.ProximitySensor.PowerOn = true;

while (true)
{
    Debug.WriteLine($"Illuminance: {sensor.AmbientLightSensor.Illuminance.Lux:F2} lux");
    Debug.WriteLine($"Proximity reading: {sensor.ProximitySensor.Distance} counts");
    Thread.Sleep(1000);
}

The proximity reading is an uncalibrated reflection count, not a physical distance. Its relationship to distance depends on the target surface, emitter settings, optical layout, and receiver configuration.