It's easy to use the MMC5603 with Python or CircuitPython, and the Adafruit_CircuitPython_MMC56x3 module. This module allows you to easily write Python code that reads the values from the MMC5603's magnetometer and ambient temperature 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 MMC5603 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 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, below shows 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 VIN (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 VIN (red wire)
- Pi GND to sensor GND (black wire)
- Pi SCL to sensor SCL (yellow wire)
- Pi SDA to sensor SDA (blue wire)
Python Installation of MMC56x3 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:
pip3 install adafruit-circuitpython-mmc56x3
If your default Python is version 3, you may need to run pip instead. Make sure you aren't trying to use CircuitPython on Python 2.x, it isn't supported!
CircuitPython Usage
To use with CircuitPython, you need to first install the MMC56x3 library, and its dependencies, into the lib folder on your CIRCUITPY drive. Then you need to update code.py with the example script.
Thankfully, we can do this in one go. In the example below, click the Download Project Bundle button below to download the necessary libraries and the code.py file in a zip file. Extract the contents of the zip file, and copy the entire lib folder and the code.py file to your CIRCUITPY drive.
Your CIRCUITPY/lib folder should contain the following folders and file:
- adafruit_bus_device/
- adafruit_register/
- adafruit_mmc56x3.mpy
Python Usage
Once you have the library pip3 installed on your computer, copy or download the following example to your computer, and run the following, replacing code.py with whatever you named the file:
python3 code.py
# SPDX-FileCopyrightText: 2021 ladyada for Adafruit Industries
# SPDX-License-Identifier: MIT
""" Display magnetometer data once per second """
import time
import board
import adafruit_mmc56x3
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_mmc56x3.MMC5603(i2c)
while True:
mag_x, mag_y, mag_z = sensor.magnetic
temp = sensor.temperature
print(
"X:{0:10.2f}, Y:{1:10.2f}, Z:{2:10.2f} uT\tTemp:{3:6.1f}*C".format(
mag_x, mag_y, mag_z, temp
)
)
print("")
time.sleep(1.0)
If running CircuitPython: Once everything is saved to the CIRCUITPY drive, connect to the serial console to see the data printed out!
If running Python: The console output will appear wherever you are running Python.
Twist and turn your MMC5603 and see the values from the magnetometer and temperature sensor print out to the REPL!
First you import the necessary modules and libraries. Then you instantiate the sensor on I2C.
Then you're ready to read data from the sensor's magnetometer and temperature sensor.
Finally, inside the loop, you see the x, y and z values from the magnetometer alongside the ambient temperature reading.
The magnetometer measures force on the x, y and z axes in micro-Teslas (uT) and the temperature sensor reads the ambient temperature in Celsius.
That's all there is to using the MMC5603 with CircuitPython!
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