SparkFun Micro Proximity Sensor - 20cm VCNL4040 (Qwiic)

Resources:

• Schematic
• KiCad Files
• Hookup Guide
• Datasheet (VCNL4040)
• Arduino Library
• Python Package

Compact Qwiic Micro Proximity and Ambient Light Sensor for Short-Range Detection

The SparkFun Micro Proximity Sensor – VCNL4040 (Qwiic) is a highly compact, low-power solution for short-range proximity and ambient light sensing in space-constrained designs. Built around the proven VCNL4040 from Vishay, this board combines an infrared emitter, a proximity sensor, and an ambient light sensor into a single IC. Its Qwiic Micro form factor makes it especially suitable for wearables, handheld devices, robotics, and touchless interfaces where PCB space and weight are critical constraints.

Designed for qualitative proximity detection up to approximately 20 cm, the VCNL4040 has no dead zone and can detect objects directly at the sensor face. This makes it ideal for gesture sensing, object presence detection, and touchless activation systems similar to those used in automatic dispensers and smart appliances. With a fixed I2C address and a single Qwiic connector, integration into 3.3V I2C systems is straightforward and solder-free.

Key Features:

• Short-Range Proximity Detection: Qualitative detection from contact to ~20 cm
• Integrated Infrared Emitter: Onboard IRED for reliable reflective proximity sensing
• Ambient Light Measurement: Built-in ALS for light-level awareness and compensation
• No Dead Zone: Detects objects directly at the sensor surface
• Qwiic Micro Form Factor: Ultra-compact board for space- and weight-sensitive designs
• Simple I2C Interface: Fixed I2C address for quick system integration