Physical computing with GPIO Zero

Short talk in my new GPIO Python library for Raspberry Pi, given at Coding Evening in London

Transcript

1. Physical computing with GPIO Zero
   Ben Nuttall
   Raspberry Pi Foundation
   UK Charity 1129409
   

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2. Ben Nuttall
   ●
   Education Developer Advocate
   at the Raspberry Pi Foundation
   – Software & project development
   – Learning resources & teacher
   training
   – Outreach
   ●
   Hobbyist turned employee
   ●
   Based in Cambridge
   ●
   @ben_nuttall on Twitter
   

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3. Python – RPi.GPIO
   import RPi.GPIO as GPIO
   from time import sleep
   GPIO.setmode(GPIO.BCM)
   GPIO.setwarnings(False)
   led = 17
   GPIO.setup(led, GPIO.OUT)
   while True:
   GPIO.output(led, True)
   sleep(1)
   GPIO.output(led, False)
   sleep(1)
   

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4. Python – GPIO Zero
   from gpiozero import LED
   from time import sleep
   led = LED(17)
   while True:
   led.on()
   sleep(1)
   led.off()
   sleep(1)
   

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5. LED
   from gpiozero import LED
   from time import sleep
   led = LED(17)
   led.on() # on
   led.off() # off
   led.toggle() # on­>off or off­>on
   led.blink() # flash on/off continuously
   

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6. LED + Button
   from gpiozero import LED, Button
   led = LED(17)
   button = Button(3)
   button.when_pressed = led.on
   button.when_released = led.off
   

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7. Motion sensor
   from gpiozero import LED, MotionSensor
   led = LED(2)
   sensor = MotionSensor(3)
   sensor.when_motion = led.on
   sensor.when_no_motion = led.off
   

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8. Traffic Lights
   from gpiozero import TrafficLights
   lights = TrafficLights(9, 10, 11)
   lights.on() # all on
   lights.off() # all off
   lights.red.on() # red on
   lights.toggle() # swap state of all lights
   

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9. Traffic Lights sequence
   lights.green.on()
   lights.amber.off()
   lights.red.off()
   while True:
   sleep(10)
   lights.green.off()
   lights.amber.on()
   sleep(1)
   lights.amber.off()
   lights.red.on()
   sleep(10)
   lights.amber.on()
   sleep(1)
   lights.green.on()
   lights.amber.off()
   lights.red.off()
   

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10. Full colour LED
    from gpiozero import RGBLED
    led = RGBLED(2, 3, 4)
    led.red.on() # full red
    led.color = (255, 0, 255) # purple
    led.blue = 100 # dim the blue value to 100
    # now (255, 0, 100)
    

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11. Motor
    from gpiozero import Motor
    from time import sleep
    motor = Motor(forward=17, back=18)
    while True:
    motor.forward()
    sleep(5)
    motor.backward()
    sleep(5)
    

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12. Robot
    from gpiozero import Robot
    from time import sleep
    robot = Robot(left=(17, 18), right=(22, 23))
    while True:
    robot.forward()
    sleep(10)
    robot.left()
    sleep(1)
    

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13. Button controlled Robot
    from gpiozero import RyanteckRobot, Button
    robot = RyanteckRobot()
    left = Button(26)
    right = Button(16)
    fw = Button(21)
    bw = Button(20)
    fw.when_pressed = robot.forward
    fw.when_released = robot.stop
    left.when_pressed = robot.left
    left.when_released = robot.stop
    right.when_pressed = robot.right
    right.when_released = robot.stop
    bw.when_pressed = robot.backward
    bw.when_released = robot.stop
    

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14. Analogue - potentiometers
    from gpiozero import RGBLED, MCP3008
    led = RGBLED(2, 3, 4)
    pot = MCP3008()
    while True:
    red = pot.value
    led.color = (red, 0, 0) # set brightness of red
    

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15. GPIO Zero - beta
    ●
    www.pythonhosted.org/gpiozero
    – Installation instructions
    – Documentation
    – Examples
    ●
    Google Doc (linked from documentation)
    – Suggestions
    – Feedback
    ●
    Contact me
    – ben@raspberrypi.org
    – @ben_nuttall on Twitter
    ●
    #gpiozero on Twitter
    

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16. CamJam EduKit
    ●
    £5 starter kit (kit 1)
    ●
    £7 sensors kit (kit 2)
    ●
    £17 robotics kit (kit 3)
    ●
    Free worksheets
    ●
    Very reusable
    

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17. Physical computing with GPIO Zero
    Ben Nuttall
    Raspberry Pi Foundation
    UK Charity 1129409
    

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