It's easy to use the VCNL4040 sensor with CircuitPython and the Adafruit CircuitPython VCNL4040 module. This module allows you to easily write Python code that reads the ambient light levels, white light levels, and proximity data from the breakout.
You can use this sensor with any CircuitPython microcontroller board or with a Linux single board computer that has GPIO and Python thanks to Adafruit_Blinka, our CircuitPython-for-Python compatibility library.
CircuitPython Microcontroller Wiring
First wire up a VCNL4040 to your board exactly as follows. Here is an example of the VCNL4040 wired to a Feather using I2C:
Python Computer Wiring
Since there's 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:
CircuitPython Installation of VCNL4040 Library
You'll need to install the Adafruit CircuitPython VCNL4040 library on your CircuitPython board.
First make sure you are running the latest version of Adafruit CircuitPython for your board.
Next you'll need to install the necessary libraries to use the hardware--carefully follow the steps to find and install these libraries from Adafruit's CircuitPython library bundle. Our CircuitPython starter guide has a great page on how to install the library bundle.
For non-express boards like the Trinket M0 or Gemma M0, you'll need to manually install the necessary libraries from the bundle:
- adafruit_vcnl4040.mpy
- adafruit_bus_device
- adafruit_register
Before continuing make sure your board's lib folder or root filesystem has the adafruit_vcnl4040.mpy, adafruit_bus_device, and adafruit_register files and folders copied over.
Next connect to the board's serial REPL so you are at the CircuitPython >>> prompt.
Python Installation of VCNL4040 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:
sudo pip3 install adafruit-circuitpython-vcnl4040
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 & Python Usage
To demonstrate the usage of the sensor we'll initialize it and read the light levels and proximity measurements from the board's Python REPL.
Run the following code to import the necessary modules and initialize the I2C connection with the sensor:
import time import board import busio import adafruit_vcnl4040 i2c = busio.I2C(board.SCL, board.SDA) sensor = adafruit_vcnl4040.VCNL4040(i2c)
Now you're ready to read values from the sensor using these properties:
- lux - The ambient light data in lux
- proximity - The proximity data measurement
For example to print ambient light level and proximity info:
For more details, check out the library documentation.
That's all there is to using the VCNL4040 sensor with CircuitPython!
# SPDX-FileCopyrightText: 2021 ladyada for Adafruit Industries
# SPDX-License-Identifier: MIT
import time
import board
import adafruit_vcnl4040
i2c = board.I2C() # uses board.SCL and board.SDA
# i2c = board.STEMMA_I2C() # For using the built-in STEMMA QT connector on a microcontroller
sensor = adafruit_vcnl4040.VCNL4040(i2c)
while True:
print("Proximity:", sensor.proximity)
print("Light: %d lux" % sensor.lux)
time.sleep(1.0)
