It's easy to use the AS7341 with Python or CircuitPython, and the Adafruit CircuitPython AS7341 module. This module allows you to easily write Python code that reads multi-spectral color intensity from the AS7341 sensor.
You can use this sensor 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 a AS7341 to your board exactly as shown below. Here's an example of wiring a Feather M4 to the sensor with I2C using one of the handy STEMMA QT connectors:
- 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)
You can also use the standard 0.100" pitch headers to wire it up on a 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'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 to the sensor using I2C and a STEMMA QT connector:
- Pi 3V to sensor VCC (red wire)
- Pi GND to sensor GND (black wire)
- Pi SCL to sensor SCL (yellow wire)
- Pi SDA to sensor SDA (blue wire)
Finally here is an example of how to wire up a Raspberry Pi to the sensor using a solderless breadboard
- Pi 3V to sensor VCC (red wire)
- Pi GND to sensor GND (black wire)
- Pi SCL to sensor SCL (yellow wire)
- Pi SDA to sensor SDA (blue wire)
CircuitPython Installation of AS7341 Library
You'll need to install the Adafruit CircuitPython AS7341 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.
Before continuing make sure your board's lib folder or root filesystem has the adafruit_AS7341.mpy file as well as the adafruit_bus_device and adafruit_register folders.
Next connect to the board's serial REPL so you are at the CircuitPython >>> prompt.
Python Installation of AS7341 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-as7341
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 measurements for each channel from the board's Python REPL.
Run the following code to import the necessary modules and initialize the I2C connection with the sensor:
from time import sleep import board from adafruit_as7341 import AS7341 i2c = board.I2C() sensor = AS7341(i2c)
Now you're ready to read values from the sensor using these properties using the code below
- channel_415nm - Data for F1, the 415nm channel
- channel_445nm - Data for F2, the 445nm channel
- channel_480nm - Data for F3, the 480nm channel
- channel_515nm - Data for F4, the 515nm channel
- channel_555nm - Data for F5, the 555nm channel
- channel_590nm - Data for F6, the 590nm channel
- channel_630nm - Data for F7, the 630nm channel
- channel_680nm - Data for F8, the 680nm channel
print("F1 - 415nm/Violet %s" % sensor.channel_415nm)
print("F2 - 445nm//Indigo %s" % sensor.channel_445nm)
print("F3 - 480nm//Blue %s" % sensor.channel_480nm)
print("F4 - 515nm//Cyan %s" % sensor.channel_515nm)
print("F5 - 555nm/Green %s" % sensor.channel_555nm)
print("F6 - 590nm/Yellow %s" % sensor.channel_590nm)
print("F7 - 630nm/Orange %s" % sensor.channel_630nm)
print("F8 - 680nm/Red %s" % sensor.channel_680nm)
# SPDX-FileCopyrightText: 2020 Bryan Siepert, written for Adafruit Industries
# SPDX-License-Identifier: MIT
from time import sleep
import board
import adafruit_as7341
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_as7341.AS7341(i2c)
sensor.gain = adafruit_as7341.Gain.GAIN_0_5X # Update the gain of the sensor
def bar_graph(read_value):
scaled = int(read_value / 1000)
return "[%5d] " % read_value + (scaled * "*")
while True:
print("F1 - 415nm/Violet %s" % bar_graph(sensor.channel_415nm))
print("F2 - 445nm//Indigo %s" % bar_graph(sensor.channel_445nm))
print("F3 - 480nm//Blue %s" % bar_graph(sensor.channel_480nm))
print("F4 - 515nm//Cyan %s" % bar_graph(sensor.channel_515nm))
print("F5 - 555nm/Green %s" % bar_graph(sensor.channel_555nm))
print("F6 - 590nm/Yellow %s" % bar_graph(sensor.channel_590nm))
print("F7 - 630nm/Orange %s" % bar_graph(sensor.channel_630nm))
print("F8 - 680nm/Red %s" % bar_graph(sensor.channel_680nm))
print("Clear %s" % bar_graph(sensor.channel_clear))
print("Near-IR (NIR) %s" % bar_graph(sensor.channel_nir))
print("\n------------------------------------------------")
sleep(1)
Page last edited January 22, 2025
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