CircuitPython Code

It's easy to use the TCS34725 sensor with CircuitPython and the Adafruit CircuitPython TCS34725 module.  This module allows you to easily write Python code that reads the color from the sensor.

First wire up a TCS34725 to your board exactly as shown on the previous pages for Arduino.   Here's an example of wiring a Feather M0 to the sensor with an I2C connection:

  • Board 3V to sensor VIN
  • Board GND to sensor GND
  • Board SCL to sensor SCL
  • Board SDA to sensor SDA

Library Installation

You'll need to install the Adafruit CircuitPython TCS34725 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 introduction guide has a great page on how to install the library bundle for both express and non-express boards.

Remember for non-express boards like the, you'll need to manually install the necessary libraries from the bundle:

  • adafruit_tcs34725.mpy
  • adafruit_bus_device

You can also download the adafruit_tcs34725.mpy from its releases page on Github.

Before continuing make sure your board's lib folder or root filesystem has the adafruit_tcs34725.mpy, and adafruit_bus_device files and folders copied over.

Next connect to the board's serial REPL so you are at the CircuitPython >>> prompt.

Usage

To demonstrate the usage of the sensor we'll initialize it and read the color and more from the board's Python REPL.

Run the following code to import the necessary modules and initialize the I2C connection with the sensor:

import board
import busio
import adafruit_tcs34725
i2c = busio.I2C(board.SCL, board.SDA)
sensor = adafruit_tcs34725.TCS34725(i2c)

Remember if you're using a board that doesn't support hardware I2C (like the ESP8266) you need to use the bitbangio module instead:

import board
import bitbangio
import adafruit_tcs34725
i2c = bitbangio.I2C(board.SCL, board.SDA)
sensor = adafruit_tcs34725.TCS34725(i2c)

Now you're ready to read values from the sensor using any of these properties:

  • color_rgb_bytes - A 3-tuple of the red, green, blue color values.  These are returned as bytes from 0 to 255 (0 is low intensity, 255 is maximum intensity).
  • temperature - The color temperature in Kelvin detected by the sensor.  This is computed from the color and might not be super accurate!
  • lux - The light intensity in lux detected by the sensor.  This is computed from the color and might not be super accurate!
print('Color: ({0}, {1}, {2})'.format(*sensor.color_rgb_bytes))
print('Temperature: {0}K'.format(sensor.temperature))
print('Lux: {0}'.format(sensor.lux))

In addition there are some properties you can both read and write to change how the sensor behaves:

  • integration_time - The integration time of the sensor in milliseconds.  Must be a value between 2.4 and 614.4.
  • gain - The gain of the sensor, must be a value of 1, 4, 16, 60.
sensor.integration_time = 200
sensor.gain = 60

See the simpletest.py example for a complete demo of printing the range every second.  Save this as main.py on the board and examine the REPL output to see the range printed every second.  Remember with the ESP8266 you might need to modify the code to use the bitbangio module!

# Simple demo of the TCS34725 color sensor.
# Will detect the color from the sensor and print it out every second.
import time

import board
import busio

import adafruit_tcs34725


# Initialize I2C bus and sensor.
i2c = busio.I2C(board.SCL, board.SDA)
sensor = adafruit_tcs34725.TCS34725(i2c)

# Main loop reading color and printing it every second.
while True:
    # Read the color as RGB bytes (0-255 values).
    r, g, b = sensor.color_rgb_bytes
    print('Detected color: #{0:02X}{1:02X}{2:02X}'.format(r, g, b))
    # Read the color temperature and lux of the sensor too.
    try:
        temp = sensor.temperature
        lux = sensor.lux
        print('Temperature: {0}K Lux: {1}'.format(temp, lux))
    except ZeroDivisionError:
        print("No light to measure")
    # Delay for a second and repeat.
    time.sleep(1.0)

That's all there is to using the TCS34725 with CircuitPython!

Last updated on 2018-03-09 at 04.35.44 PM Published on 2013-05-21 at 01.06.50 PM