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Nina Zakharenko - Light Up Your Life -- With Python and LEDs! PyCascades 2019

Nina Zakharenko - Light Up Your Life -- With Python and LEDs! PyCascades 2019

Python opens a whole new world of working with wearable electronics. MicroPython is a Python variant can run with just 256k of storage space and 16k of RAM. CircuitPython is a fork of MicroPython focused on teaching. Learn how to program LEDs with Python, to light up your life with code and creativity.


Nina Zakharenko is a Senior Cloud Developer Advocate at Microsoft, focusing on Python. Before joining Microsoft, she was a Senior Software Engineer with over a decade of experience writing software for companies like Reddit, Meetup, and HBO. In her spare time, she enjoys snowboarding, hiking, and tinkering with wearable electronics from her home base in Portland, OR.

Nina Zakharenko

February 24, 2019

More Decks by Nina Zakharenko

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  1. Light Up Your Life -- With Python & LEDs! bit.ly/pyc_leds

    (download for clickable links) Code at: git.io/techtalks Nina Zakharenko - @nnja
  2. Livetweet! use #PyCascades2019 @nnja Slides: bit.ly/pyc_leds

  3. Where To Start When You're Just Getting Started » Hardware

    Options » Programming LEDs » Debugging with print() statements » Tools » Libraries » Projects @nnja
  4. some of my projects

  5. Hardware Options » Raspberry Pi Zero W » Small Development

    Kit w/ wireless and bluetooth connectivity » BBC micro:bit » computing device aimed at learning » Adafruit - m0 and m4 line of devices » & lots more... @nnja
  6. @nnja

  7. my ❤ : The HalloWing m0 a spooky development kit

  8. @nnja

  9. Adafruit Circuit PlayGround Express Learning Platform - Cost: $25-> @nnja

  10. Python's Batteries Included Philosophy “The Python source distribution has long

    maintained the philosophy of "batteries included" -- having a rich and versatile standard library which is immediately available, without making the user download separate packages. This gives the Python language a head start in many projects.” PEP 206 @nnja
  11. CircuitPlaygroundExpress Tour

  12. MicroPython & CircuitPython » MicroPython is a variant of Python

    3 designed to run of microcontrollers. » Runs within just 256k of code space and 16k of RAM. » CircuitPython is an education friendly Adafruit fork of MicroPython » Both are open source! @nnja
  13. Libraries » Many available » Need to be in the

    lib folder » Download from: git.io/circuitpythonlib » ! We're interested in adafruit_circuitplayground.express, so we can interact with the board. @nnja
  14. from adafruit_circuitplayground.express import cpx cpx.button_a # Is Button A Pressed?

    True or False cpx.button_b # Is Button B Pressed? True or False learn.adafruit.com/circuitpython-made-easy-on-circuit-playground-express/
  15. RGB LEDs RGB LEDs have one LED of each color

    - red, green, and blue. By combining the amount and intensity of these colors (255 * 255 * 255) you can produce over 16 million color variations! image source: randomnerdtutorials.com/electronics-basics-how-do-rgb-leds-work/
  16. Neopixels in action @nnja

  17. # Cycle between Red, Green, Blue each time a button

    is pressed from adafruit_circuitplayground.express import cpx import time RED = (255, 0, 0) # 255 Red, 0 Green, 0 Blue GREEN = (0, 255, 0) # 0 Red, 255 Green, 0 Blue BLUE = (0, 0, 255) # 0 Red, 0 Green, 255 Blue cpx.pixels.brightness = 0.1 my_colors = [RED, GREEN, BLUE] color_pos = 0 while True: # Keep looping forever... cpx.pixels.fill(my_colors[color_pos]) if cpx.button_a or cpx.button_b: # Button A or B was pressed color_pos = (color_pos + 1) % len(my_colors) time.sleep(0.2) # Sleep, to make the button less sensitive
  18. @nnja

  19. How to program it? » Plug it in with a

    data + charge USB cable » See a CircuitPython drive? » on Mac OS in /Volumes/CIRCUITPY » Otherwise, install CircuitPython » Next, edit & save the code.py (or main.py) file. Your code runs instantly! ! @nnja
  20. @nnja

  21. I ! Programming with Visual Studio Code + The Python

    Extension $ # To open on Mac OS $ code /Volumes/CIRCUITPY/ @nnja
  22. Programming with Mu Editor: a simple Python editor for beginner

  23. Programming with EduBlocks (in Python3! ! ) » Newly announced

    integration » Drag n Drop scratch-like code editor » It's Python3 under the hood! » Switch between code + blocks @nnja
  24. Investigating with print statements my_colors = [("Red", RED), ("Green", GREEN),

    ("Blue", BLUE)] color_pos = 0 while True: # Keep looping forever... name, color = my_colors[color_pos] cpx.pixels.fill(color) if cpx.button_a or cpx.button_b: # Button A or B was pressed color_pos = (color_pos + 1) % len(my_colors) next_name, _ = my_colors[color_pos] print("Changing color from %s to %s" % (name, next_name)) time.sleep(0.2) # Sleep, to make the button less sensitive @nnja
  25. View print statements & errors via the serial console »

    To see print() statements or errors, you need to receive output from the Circuit Play Ground Express by opening a connection to the serial console. » ! You won't see any output without it. @nnja
  26. easy serial console: with mu editor The easiest way to

    connect to the serial console is the serial button in the my editor toolbar. @nnja
  27. @nnja

  28. advanced serial console: the terminal On Mac OS, can use

    the terminal and screen program to connect to the serial console on the Circuit Playground Express. $ ls /dev/tty.* # Select the usbmodem $ screen /dev/tty.board_name 115200 # `115200` is the baud rate. To quit screen, press ctrl+a followed by k. Or, learn how to connect via the terminal in other OSes
  29. None
  30. Powering Your Projects [1/2] » micro USB (same port for

    power & programming) » from a computer, portable phone charger, or wall » battery packs (JST connector) » need minimum 3.5V DC. Power with 3 household AAA batteries + enclosure with correct connector.
  31. Powering Your Projects [2/2] » lithium polymer (li-poly) batteries »

    warning: only for advanced users » small, lightweight, energy dense, fragile » needs special care! » cannot be heated, punctured, or bent » ! for kids w/o supervision » requires additional charger
  32. Putting it all together » Adafruit demo code: bit.ly/initial_cpe »

    Initial directory: bit.ly/initial_cpe_dir » Demo covers a majority of the features, prints out sensor readings, etc. » There's even a flag you can set to turn the Circuit Playground Express into a little piano using the capacitive touch pads! @nnja
  33. Microsoft Make Code ✨ Coding not required ✨ makecode.adafruit.com incudes

    built in emulator learn.adafruit.com/circuit-playground-express-con-badge/
  34. Find projects, or Share yours. · Adafruit Guides · Microsoft

    Make Code · Instructables ← solder-free Circuit PlayGround Express Jack-o- Lantern learn.adafruit.com/circuit-playground-jack-o-lantern
  35. Next Steps » Buy (or borrow) a device of your

    choice or use the MakeCode emulator » Pick your editor (Visual Studio Code, Mu, etc..) » Write your own code » Use a library » Or start with a shared project ... start with Python on hardware in no time! @nnja
  36. github.com/nnja/pyearrings

  37. news & announcements 1.Hack on CircuitPython with Scott → 2.CPE

    in PyCon US Swag Bags ! 3.CPE Lunchbox Kits @ Microsoft PyCon US Booth
  38. Thank You! @nnja Python @ Microsoft: bit.ly/pyc_msft Code: git.io/techtalks *Additional

    resources on the next slide
  39. Resources » Circuit PlayGround Express Library - learn.adafruit.com/circuitpython-made-easy-on- circuit-playground-express/ »

    Circuit Python Essentials - cdn-learn.adafruit.com/downloads/pdf/circuitpython- essentials.pdf » AdaFruit Python Compatible m0 www.adafruit.com/?q=m0 and m4 www.adafruit.com/?q=m4 @nnja