IRIS

MDA Datalogger

Authored by Andrew Y

About

This is a guide on how to set up and operate the new M4 datalogger, accompanying plotter script, and experimental GUI app for the 2025 MD Anderson trip.

Setting Up Your Computer and M4!

Please Read!

This guide should apply to everyone on a modern operating system (Windows, MacOS, most modern Linux distros).

Also, if I refer to a script, I am most likely referring to a Python program that will run on your computer/laptop. If I refer to a sketch, I am most likely referring to an Arduino program that will run on your MCU.

Tip

Since I primarily use Linux, I will refer to Terminal, cmd, PowerShell, and whatever other analogous app as “terminal”. For Windows users, if you see a command run as sudo in the guide below, you will have to run that same command (without including sudo) in an elevated/administrator cmd or PowerShell window.

General Requirements

  • Arduino IDE 2.3+
    • Legacy IDE (1.8.X) should work, but the GUI is different and you will have to find the analogous menus.
  • uv
    • Using uv python install, install a recent version of Python (3.12+)
    • Please double check uv’s recognized Python installations by running uv python list in terminal!
  • A Local Copy of our Code
  • A Local Copy of the GUI
    • Make sure to pull the textual-attempt branch
  • Install a Toggle Switch connecting GPIO 5 and Gnd pins:

Arduino IDE

Boards Manager

The bare IDE will not recognize our microcontrollers (MCUs) without some set up.

  1. Open Arduino IDE.
  2. Go to File→Preferences
  3. At the bottom, there will be an empty text box titled “Additional boards manager URLS”. Paste in the following:
https://adafruit.github.io/arduino-board-index/package_adafruit_index.json
  1. …and click OK.
  2. Next, in the left sidebar, open the Boards Manager.
  3. Search for and install Adafruit SAMD Boards.
    • This will install the proper dependencies for our MCUs.

Library Manager

The following libraries are required for the datalogger and the data-offloading

  • SdFat - Adafruit Fork
    • and associated dependencies (should auto install)
  • TinyUSB

Validating Your Setup!

Now we’ll run a test program on your MCU to make sure the basics are set up properly. Make sure your MCU is plugged into your computer before proceeding.

  1. In Arduino IDE, go to File→Examples→Basics→Blink. This should look something like this:
    • This will open a new window with the Blink example sketch.
  2. In Arduino IDE, you should see a dropdown menu in the top left that looks something like this:
    • Windows users will see ports such as COM6 or COM4
    • Mac users will see ports such as /dev/cu.usbmodem1101
      • You may see a pop up to install xcrun. Allow the install to finish before proceeding.
    • Linux users will see ports such as /dev/ttyACM0
  3. If your setup is correct, you should see an entry in there for every connected MCU. Select the one you’d like to test.
  4. Click the → button in the top left to compile and upload the example sketch onto your MCU!
  5. Once the upload is complete, you should see a small LED on your MCU start blinking near the USB port. If everything so far has worked, then you should be good to go!

Using the MDA Sketch!

Dependencies

The Code

Please make sure you are looking at the cleanup branch!

  • You will find the sketch at: IRIS-Project\packages\M4\Toggle Switch Datalogger\dma_dual_adc_unified_SfFat\dma_dual_adc_unified_SfFat.ino.
    • You need all files in here. Not just dma_dual_adc_unified_SdFat.ino

Hardware

  • MCU: Adafruit Feather M4 Express with SD+RTC Featherwing
  • SD Card formatted to exFat
  • Toggle Switch connecting GPIO 5 and Gnd pins
  • Data Collection pins:
    • A4
    • A1
    • A2
    • A3

Running the Sketch

  1. Open dma_dual_adc_unified_SfFat.ino using Arduino IDE, or open Arduino IDE first and go to File→Open… to open dma_dual_adc_unified_SfFat.ino.
    • You may see a new IDE window open with the sketch opened.
  2. Use the dropdown menu to select your M4 MCU:
    • Make note of the listed port!
      • In this case, the MCU is connected to serial port /dev/ttyACM0
  3. Click the → button in the top left to compile and upload the sketch. Wait for it to complete.
  4. The MCU should now be ready to collect data.

Important

The M4 will collect data when the switch is in the OFF position. The M4 will pause data collection when the switch is in the ON position.

This is a bug, but has no other affects besides inverting switch behavior.

Halt data collection before cutting power or removing SD card!

In order to reduce performance impacts, the MCU only safely commits recent data to the SD card when the switch is flicked to the ON position (AKA data collection is paused).

Using the Dat Plotter Script!

Dependencies

The Code

Please make sure you are looking at the cleanup branch of the IRIS-Project repo!

  • The script can be found at: IRIS-Project\packages\M4\Toggle Switch Datalogger\m4_dma_dat_plotter\m4_dma_dat_plotter.py.
  • You will find the sketch at: IRIS-Project\packages\M4\Toggle Switch Datalogger\dma_dual_adc_unified_SfFat\dma_dual_adc_unified_SdFat.ino.
    • You need all files in here. Not just dma_dual_adc_unified_SdFat.ino

Python

  • uv will handle all dependencies via the pyproject.toml file when you run the script.

Running the Script!

  1. Open a terminal window in the script’s directory, or cd into it as needed.
  2. Run the script via uv run ./m4_dma_dat_plotter.py [-seq] <NUM_RESULTS> <DATA DIRECTORY>
    • NUM_RESULTS: same value as found in config.h. Currently, 8192.
    • DATA DIRECTORY: the directory path which holds the desired .dat files to plot

Graph View