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.

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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.

Transcript

1. Light Up Your Life --
   With Python & LEDs!
   bit.ly/pyc_leds
   (download for clickable links)
   Code at: git.io/techtalks
   Nina Zakharenko - @nnja
   

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2. Livetweet!
   use #PyCascades2019
   @nnja
   Slides: bit.ly/pyc_leds
   

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3. Where To Start
   When You're Just Getting Started
   » Hardware Options
   » Programming LEDs
   » Debugging with print() statements
   » Tools
   » Libraries
   » Projects
   @nnja
   

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4. some of my projects
   

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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
   

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6. @nnja
   

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

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8. @nnja
   

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

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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
    

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11. CircuitPlaygroundExpress Tour
    

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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
    

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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
    

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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/
    

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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/
    

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16. Neopixels in action
    @nnja
    

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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
    

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18. @nnja
    

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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
    

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20. @nnja
    

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21. I
    !
    Programming
    with Visual Studio
    Code
    + The Python
    Extension
    $ # To open on Mac OS
    $ code /Volumes/CIRCUITPY/
    @nnja
    

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22. Programming with Mu Editor:
    a simple Python editor for beginner programmers
    

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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
    

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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
    

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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
    

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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
    

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27. @nnja
    

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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
    

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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.
    

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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
    

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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
    

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33. Microsoft Make Code
    ✨
    Coding not
    required
    ✨
    makecode.adafruit.com
    incudes built in emulator
    learn.adafruit.com/circuit-playground-express-con-badge/
    

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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
    

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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
    

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36. github.com/nnja/pyearrings
    

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37. news &
    announcements
    1.Hack on CircuitPython with
    Scott →
    2.CPE in PyCon US Swag Bags
    !
    3.CPE Lunchbox Kits @
    Microsoft PyCon US Booth
    

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38. Thank You!
    @nnja
    Python @
    Microsoft:
    bit.ly/pyc_msft
    Code: git.io/techtalks
    *Additional resources on the next slide
    

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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
    

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