# Adafruit VCNL4040 Proximity Sensor ## Overview ![](https://cdn-learn.adafruit.com/assets/assets/000/078/981/medium800/adafruit_products_4161_iso_ORIG_2019_08.jpg?1564788811) The VCNL4040 is a handy two-in-one sensor, with a proximity sensor that works from 0 to 200mm (about 7.5 inches) and light sensor with range of 0.0125 to 6553 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 particularly calm bumble bee, the VCNL4040 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 VCNL4040 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). ![](https://cdn-learn.adafruit.com/assets/assets/000/078/982/medium800/adafruit_products_4161_top_demo_ORIG_2019_08.jpg?1564788857) "OK, _finally_ I can get started on my bee measuring and light sensing project, but _how do I use it?"_ you say. To make life easier so you can focus on your important work, we've taken the VCNL4040 and put it onto a breakout PCB along with support circuitry to let you use this little wonder with 3.3V (Feather) or 5V (Arduino/ Metro328) logic levels. Additionally, since it speaks I2C, you can easily connect it up with two wires (plus power and ground!).  We've even included [SparkFun qwiic](https://learn.adafruit.com/ds3502-i2c-potentiometer/) compatible** [STEMMA QT](https://learn.adafruit.com/introducing-adafruit-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 CircuitPython/Python or Arduino drivers to easily interface with the VCNL4040 and make approximate approximations of proximity in no time! ![](https://cdn-learn.adafruit.com/assets/assets/000/078/985/medium800/adafruit_products_4161_quarter_ORIG_2019_08.jpg?1564789177) To give you some ability to tune your measurements for your situation, the VCNL4040 lets you adjust the integration time (how long light is being measured) to set the sensitivity of your measurements depending on the lighting conditions. With an integration time of 80ms, since the sensor is only collecting measurements for a short period of time, each measured bit of light represents a larger amount of light. For this reason the maximum range in lux for the 80ms integration time is 6553.5 lux. If you use a longer integration time and get the same amount of light measurements "events", you know that there is comparatively less light because we're waiting around longer for light to show up and getting the same number, meaning the rate of light events is lower. For this reason at the maximum integration time of 640ms the VCNL4040 will only measure up to 819.2 lux. It is also worth keeping in mind that as you increase the integration time you are also increasing the sensitivity and resolution within the measurement range In addition to adjusting the sensitivity of light measurements, you can change the current and duty cycle of the IR LED that powers the proximity detection to adjust how sensitive proximity measurements are - [Next Page](https://learn.adafruit.com/adafruit-vcnl4040-proximity-sensor/pinouts.md) ## Primary Products ### Adafruit VCNL4040 Proximity and Lux Sensor - STEMMA QT / Qwiic [Adafruit VCNL4040 Proximity and Lux Sensor - STEMMA QT / Qwiic](https://www.adafruit.com/product/4161) The VCNL4040 is a handy two-in-one sensor, with a proximity sensor that works from **0 to 200mm** (about 7.5 inches) and light sensor with range of **0.0125 to 6553 lux**. We've all been there. That thing is _close_ but _how close?_... In Stock [Buy Now](https://www.adafruit.com/product/4161) [Related Guides to the Product](https://learn.adafruit.com/products/4161/guides) ## Featured Products ### STEMMA QT / Qwiic JST SH 4-pin Cable - 100mm Long [STEMMA QT / Qwiic JST SH 4-pin Cable - 100mm Long](https://www.adafruit.com/product/4210) This 4-wire cable is a little over 100mm / 4" long and fitted with JST-SH female 4-pin connectors on both ends. Compared with the chunkier JST-PH these are 1mm pitch instead of 2mm, but still have a nice latching feel, while being easy to insert and remove. Out of Stock [Buy Now](https://www.adafruit.com/product/4210) [Related Guides to the Product](https://learn.adafruit.com/products/4210/guides) ### STEMMA QT / Qwiic JST SH 4-pin to Premium Male Headers Cable [STEMMA QT / Qwiic JST SH 4-pin to Premium Male Headers Cable](https://www.adafruit.com/product/4209) This 4-wire cable is a little over 150mm / 6" long and fitted with JST-SH female 4-pin connectors on one end and premium Dupont male headers on the other. Compared with the chunkier JST-PH these are 1mm pitch instead of 2mm, but still have a nice latching feel, while being easy to insert... In Stock [Buy Now](https://www.adafruit.com/product/4209) [Related Guides to the Product](https://learn.adafruit.com/products/4209/guides) ### JST SH 4-pin Right Angle Connector (10-pack) [JST SH 4-pin Right Angle Connector (10-pack)](https://www.adafruit.com/product/4208) If you're a DIY enthusiast who likes to _micro_-manage your project's connections, here is a 10-pack of some _micro_ JST SH connectors! They're solid plastic with 4 x 1mm pitch through-hole mounting tabs. In an SMT line you can just paste... In Stock [Buy Now](https://www.adafruit.com/product/4208) [Related Guides to the Product](https://learn.adafruit.com/products/4208/guides) ### Adafruit METRO 328 - Arduino Compatible - with Headers [Adafruit METRO 328 - Arduino Compatible - with Headers](https://www.adafruit.com/product/2488) This is the  **Adafruit METRO Arduino-Compatible - with headers. ** It's a fully assembled and tested microcontroller and physical computing board with through-hole headers attached.  If you don't want a Metro with the headers attached for... In Stock [Buy Now](https://www.adafruit.com/product/2488) [Related Guides to the Product](https://learn.adafruit.com/products/2488/guides) ### Adafruit METRO M0 Express - designed for CircuitPython [Adafruit METRO M0 Express - designed for CircuitPython](https://www.adafruit.com/product/3505) Metro is our series of microcontroller boards for use with the Arduino IDE. This new **Metro M0 Express** board looks a whole lot like our [original Metro 328](https://www.adafruit.com/product/2488), but with a huge upgrade. Instead of the ATmega328, this Metro... In Stock [Buy Now](https://www.adafruit.com/product/3505) [Related Guides to the Product](https://learn.adafruit.com/products/3505/guides) ### Adafruit Feather M4 Express - Featuring ATSAMD51 [Adafruit Feather M4 Express - Featuring ATSAMD51](https://www.adafruit.com/product/3857) It's what you've been waiting for, the Feather M4 Express featuring ATSAMD51. This Feather is fast like a swift, smart like an owl, strong like a ox-bird (it's half ox, half bird, OK?) This feather is powered by our new favorite chip, the **ATSAMD51J19** -  with... 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