GPIO Zero - AmsterJam

Transcript

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   GPIO Zero Ben Nuttall Raspberry Pi Foundation UK Charity 1129409

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   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
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   GPIO Pins – General Purpose Input/Output

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   GPIO Zero: a friendly API for GPIO devices from gpiozero

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

   button = Button(4) led.source = button.values
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   GPIO Zero supports...

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   GPIO Zero Device Hierarchy!

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

    >>> led.value 1.0 >>> led.value = 0
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    .value >>> led = PWMLED(17) >>> pot = MCP3008() >>>

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

    led.value = pot.value >>> while True: ... led.value = pot.value
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    Source / Values Output Device .value .values .source Input Device

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

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

    LED(17) button = Button(2) led.source = button.values
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    Processing values Output Device .value .values .source Input Device .value

    .values function
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    Source tools from gpiozero import Button, LED from gpiozero.tools import

    negated led = LED(4) btn = Button(17) led.source = negated(btn.values)
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    Combining values Output Device .value .values .source Input Device .value

    .values Source tool Input Device .value .values
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    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)
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    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
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    MockPin $ GPIOZERO_PIN_FACTORY=mock python3 >>> from gpiozero import LED >>>

    led = LED(22) >>> led.blink() >>> led.value True >>> led.value False
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    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
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    pigpio - remote GPIO from Pi or PC

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    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()
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    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()
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    Internal devices • TimeOfDay • PingServer • CPUTemperature • More

    coming soon • Make your own!
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    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
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    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)
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    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
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    guizero

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    Raspberry Pi Desktop x86

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    Raspberry Pi Desktop x86 – Remote GPIO

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    GitHub

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    pinout command line tool

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    Read the docs!

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    The MagPi

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    GPIO Zero Book

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    GPIO Zero Ben Nuttall Raspberry Pi Foundation UK Charity 1129409