GPIO Zero - AmsterJam

Transcript

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

2. Ben Nuttall • Raspberry Pi Community Manager • Based in

   Cambridge • Creator of gpiozero python library • Columnist on opensource.com • github.com/bennuttall • twitter.com/ben_nuttall • ben@raspberrypi.org

3. GPIO Pins – General Purpose Input/Output

4. GPIO Zero: a friendly API for GPIO devices from gpiozero

   import LED led = LED(17) led.on()

5. Multi-paradigm: procedural from gpiozero import LED, Button led = LED(17)

   button = Button(4) while True: if button.is_pressed: led.on() else: led.off()

6. Multi-paradigm: event-driven from gpiozero import LED, Button led = LED(17)

   button = Button(4) button.when_pressed = led.on button.when_released = led.off

7. Multi-paradigm: declarative from gpiozero import LED, Button led = LED(17)

   button = Button(4) led.source = button.values

8. GPIO Zero supports...

9. GPIO Zero Device Hierarchy!

10. .value >>> led = PWMLED(17) >>> led.value 0.0 >>> led.on()

    >>> led.value 1.0 >>> led.value = 0

11. .value >>> led = PWMLED(17) >>> pot = MCP3008() >>>

    led.value = pot.value

12. .value >>> led = PWMLED(17) >>> pot = MCP3008() >>>

    led.value = pot.value >>> while True: ... led.value = pot.value

13. Source / Values Output Device .value .values .source Input Device

    .value .values

14. Source / Values Output Device .value .values .source Input Device

    .value .values

15. Source / Values from gpiozero import LED, Button led =

    LED(17) button = Button(2) led.source = button.values

16. Processing values Output Device .value .values .source Input Device .value

    .values function

17. Source tools from gpiozero import Button, LED from gpiozero.tools import

    negated led = LED(4) btn = Button(17) led.source = negated(btn.values)

18. Combining values Output Device .value .values .source Input Device .value

    .values Source tool Input Device .value .values

19. Source tools from gpiozero import Button, LED from gpiozero.tools import

    all_values button_a = Button(2) button_b = Button(3) led = LED(17) led.source = all_values(button_a.values, button_b.values)

20. Supporting multiple back-ends • RPi.GPIO • Implemented in C, current

    default • RPIO • Implemented in C • pigpio • Python wrapper for C library, runs as daemon, remote pins • Native • Pure Python, limited functionality, experimental • MockPin & MockPWMPin • Pure Python, used in test suite

21. MockPin $ GPIOZERO_PIN_FACTORY=mock python3 >>> from gpiozero import LED >>>

    led = LED(22) >>> led.blink() >>> led.value True >>> led.value False

22. MockPin >>> from gpiozero import LED >>> led = LED(22)

    >>> button = Button(23) >>> led.source = button.values >>> led.value False >>> button.pin.drive_low() >>> led.value True

23. pigpio - remote GPIO from Pi or PC

24. pigpio - remote GPIO from Pi or PC from gpiozero

    import LED from gpiozero.pins.pigpio import PiGPIOFactory factory = PiGPIOFactory('192.168.0.2') led = LED(22, pin_factory=factory) led.blink()

25. pigpio - remote GPIO from Pi or PC $ PIGPIO_ADDR=192.168.0.2

    python3 led.py from gpiozero import LED led = LED(22) led.blink()

26. Internal devices • TimeOfDay • PingServer • CPUTemperature • More

    coming soon • Make your own!

27. Energenie tortoise lamp from gpiozero import Energenie, TimeOfDay from datetime

    import time lamp = Energenie(1) daytime = TimeOfDay(time(9), time(18)) lamp.source = daytime.values

28. Is the internet working? from gpiozero import LED, PingServer from

    gpiozero.tools import negated green = LED(17) red = LED(18) google = PingServer('google.com') green.source = google.values green.source_delay = 60 red.source = negated(green.values)

29. CPU Temperature from gpiozero import LEDBarGraph, CPUTemperature cpu = CPUTemperature(min_temp=50,

    max_temp=90) leds = LEDBarGraph(2, 3, 4, 5, 6, 7, 8, pwm=True) leds.source = cpu.values

30. guizero

31. Raspberry Pi Desktop x86

32. Raspberry Pi Desktop x86 – Remote GPIO

33. GitHub

34. pinout command line tool

35. Read the docs!

36. The MagPi

37. GPIO Zero Book

38. GPIO Zero Ben Nuttall Raspberry Pi Foundation UK Charity 1129409