Python Picamera with GPIO Zero - Picademy USA

Python camera GPIO workshop given at Picademy USA, featuring picamera and GPIO Zero

Transcript

1. Python Picamera
   featuring GPIO Zero
   Introducing the camera board
   and Python module
   

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2. Who's this guy?
   Ben Nuttall
   Education Developer Advocate
   Raspberry Pi Foundation
   @ben_nuttall
   ben@raspberrypi.org
   github.com/bennuttall
   

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3. USA Tour 2014
   

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4. Raspberry Pi camera module
   - 5Mpx
   - Full HD
   - Photo & video
   - Command line
   - Python module
   - Infra-red camera
   

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5. What you will learn
   ●
   How to connect the camera module
   ●
   How to use the Python picamera module to control the camera
   ●
   How to use the GPIO Zero Button interface to control the
   camera
   ●
   How to use loops to repeat commands
   ●
   How simple changes to code make different projects
   ●
   Ideas for camera projects
   

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6. Connect the camera
   

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7. Add a GPIO Button
   

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8. Boot the Pi and open Python 3
   

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9. IDLE Python Shell
   >>> from picamera import PiCamera
   >>> from gpiozero import Button
   >>> camera = PiCamera()
   >>> button = Button(17)
   >>> button.when_pressed = camera.start_preview
   >>> button.when_released = camera.stop_preview
   

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10. GPIO Zero Button
    button.is_pressed
    button.wait_for_press()
    button.wait_for_release()
    button.when_pressed = some_function
    button.when_released = some_function
    

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11. GPIO Zero Button
    while True:
    if button.is_pressed:
    print("Pressed")
    while True:
    if not button.is_pressed:
    print("Not pressed")
    

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12. GPIO Zero Button
    while True:
    button.wait_for_press()
    print("Pressed")
    button.wait_for_release()
    print("Released")
    

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13. GPIO Zero Button
    led = LED(4)
    button = Button(17)
    button.when_pressed = led.on
    button.when_released = led.off
    

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14. GPIO Zero Button
    def hello():
    print("Pressed")
    button.when_pressed = hello
    

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15. Open a new file
    ●
    File > New File
    ●
    File > Save
    ●
    Save as camera.py
    

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16. Take a selfie
    from picamera import PiCamera
    from time import sleep
    with PiCamera() as camera:
    camera.start_preview()
    sleep(3)
    camera.capture("/home/pi/image.jpg")
    camera.stop_preview()
    Save and run:
    Ctrl + S
    F5
    

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17. Add GPIO Button code
    from picamera import PiCamera
    from gpiozero import Button
    from time import sleep
    button = Button(17)
    with PiCamera() as camera:
    camera.start_preview()
    button.wait_for_press()
    sleep(3)
    camera.capture("/home/pi/image2.jpg")
    camera.stop_preview()
    Save and run:
    Ctrl + S
    F5
    

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18. Add a loop
    with PiCamera() as camera:
    camera.start_preview()
    for i in range(5):
    button.wait_for_press()
    sleep(3)
    camera.capture("/home/pi/image%s.jpg" % i)
    camera.stop_preview()
    Save and run:
    Ctrl + S
    F5
    

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19. What's the difference?
    for i in range(5):
    button.wait_for_press()
    sleep(3)
    camera.capture("/home/pi/image%s.jpg" % i)
    button.wait_for_press()
    for i in range(5):
    sleep(3)
    camera.capture("/home/pi/image%s.jpg" % i)
    

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20. What next?
    ●
    Time-lapse
    ●
    Stop motion animation
    ●
    Wildlife camera
    

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21. What next?
    ●
    Sensor trigger
    ●
    Send to social media
    ●
    Robotics
    

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22. Two Buttons?
    left = Button(4)
    right = Button(14)
    left.when_pressed = camera.start_preview
    left.when_released = camera.stop_preview
    right.when_pressed = camera.capture
    ←
    Why wouldn't
    this work?
    

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23. Custom capture function
    def capture():
    camera.capture("/home/pi/image.jpg")
    right.when_pressed = capture
    

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24. Custom capture function
    i = 0
    def capture():
    global i
    camera.capture("/home/pi/image%s.jpg" % i)
    i += 1
    right.when_pressed = capture
    Alternatively,
    use the datetime
    module
    

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25. GPIO Zero Motion Sensor
    sensor = MotionSensor(14)
    sensor.is_motion
    sensor.wait_for_motion()
    sensor.wait_for_no_motion()
    sensor.when_motion = some_function
    sensor.when_no_motion = some_function
    

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26. picamera
    camera.start_preview()
    camera.stop_preview()
    camera.capture(output)
    camera.start_recording(output)
    camera.stop_recording()
    camera.add_overlay(source)
    

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27. picamera
    camera.resolution = (1280, 720)
    camera.rotation = 180
    camera.annotate_text = "Hello world"
    

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28. Documentation and help guides
    ●
    picamera.readthedocs.org
    ●
    gpiozero.readthedocs.org
    ●
    raspberrypi.org/resources
    ●
    raspberrypi.org/education/downloads
    

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29. Python Picamera
    featuring GPIO Zero
    Introducing the camera board
    and Python module
    

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