Physical computing with GPIO Zero - Peterborough Raspberry Jam

Transcript

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

   UK Charity 1129409

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 (but from the North) • @ben_nuttall on Twitter

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)

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)

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

6. LED + Button from gpiozero import LED, Button led =

   LED(17) button = Button(3) button.when_pressed = led.on button.when_released = led.off

7. Source + Values from gpiozero import LED, Button led =

   LED(17) button = Button(3) led.source = button.values

8. LED - PWM from gpiozero import PWMLED from time import

   sleep led = PWMLED(17) led.on() # on led.off() # off led.value = 0.5 # half brightness

9. Motion sensor from gpiozero import LED, MotionSensor led = LED(2)

   sensor = MotionSensor(3) sensor.when_motion = led.on sensor.when_no_motion = led.off

10. Light sensor from gpiozero import LED, LightSensor led = LED(2)

    sensor = LightSensor(3) while True: sensor.wait_for_light() print("It's light!") sensor.wait_for_dark() print("It's dark")

11. 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

12. 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()

13. TrafficHat from gpiozero import TrafficHat th = TrafficHat() th.lights.red.on() th.lights.amber.on()

    th.button.when_pressed = th.on th.button.when_released = th.off

14. TrafficHat - PWM from gpiozero import TrafficHat th = TrafficHat(pwm=True)

    th.lights.red.value = 0.2 th.lights.amber.value = 0.4 th.lights.green.value = 0.8

15. Push button stop motion from gpiozero import Button from picamera

    import PiCamera button = Button(4) with PiCamera() as camera: camera.start_preview() frame = 1 while True: button.wait_for_press() camera.capture('/home/pi/frame%03d.jpg' % frame) frame += 1

16. Full colour LED from gpiozero import RGBLED led = RGBLED(2,

    3, 4) led.red.on() # full red led.color = (1, 0, 1) # purple led.blue = 0.3 # dim the blue value to 0.3 # now (1, 0, 0.3)

17. Motor from gpiozero import Motor from time import sleep motor

    = Motor(forward=17, backward=18) while True: motor.forward() sleep(5) motor.backward() sleep(5)

18. 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)

19. 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

20. Analogue - potentiometers from gpiozero import MCP3008 pot = MCP3008()

    while True: print(pot.value)

21. Dial up the brightness! from gpiozero import PWMLED, MCP3008 led

    = PWMLED(2) pot = MCP3008() while True: led.value = pot.value

22. Dial up the brightness! from gpiozero import PWMLED, MCP3008 led

    = PWMLED(2) pot = MCP3008() led.source = pot.values

23. Analogue - potentiometers from gpiozero import RGBLED, MCP3008 led =

    RGBLED(red=2, green=3, blue=4) red_pot = MCP3008(channel=0) green_pot = MCP3008(channel=1) blue_pot = MCP3008(channel=2) while True: led.red = red_pot.value led.green = green_pot.value led.blue = blue_pot.value

24. Analogue - potentiometers from gpiozero import RGBLED, MCP3008 led =

    RGBLED(red=2, green=3, blue=4) red_pot = MCP3008(channel=0) green_pot = MCP3008(channel=1) blue_pot = MCP3008(channel=2) led.red.source = red_pot.values led.green.source = green_pot.values led.blue.source = blue_pot.values

25. GPIO Music Box from gpiozero import Button import pygame.mixer from

    pygame.mixer import Sound pygame.mixer.init() sound_pins = { 2: Sound("samples/drum_tom_mid_hard.wav"), 3: Sound("samples/drum_cymbal_open.wav"), } buttons = [Button(pin) for pin in sound_pins] for button in buttons: sound = sound_pins[button.pin] button.when_pressed = sound.play

26. Install GPIO Zero • Pre-installed in Raspbian Jessie since 21

    Nov • Update with: sudo apt­get update • Install with: sudo apt­get install python3­gpiozero or: sudo apt­get install python­gpiozero

27. GPIO Zero • www.pythonhosted.org/gpiozero – Installation instructions – Documentation –

    Examples • GitHub Issues – Suggestions – Feedback • Contact me – ben@raspberrypi.org – @ben_nuttall on Twitter • #gpiozero on Twitter

28. CamJam EduKit • £5 starter kit (kit 1) • £7

    sensors kit (kit 2) • £17 robotics kit (kit 3) • Free worksheets • Very reusable

29. Raspberry Pi blog

30. The MagPi

31. The MagPi

32. Pi Zero

33. Conductive paint

34. Conductive thread

35. Physical computing with GPIO Zero Ben Nuttall Raspberry Pi Foundation

    UK Charity 1129409