Remote GPIO

Transcript

1. Remote GPIO
   with GPIO Zero, pigpio and the Traffic HAT
   Ben Nuttall
   Raspberry Pi Foundation
   UK Charity 1129409
   

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2. Open Thonny Python IDE
   

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3. Type into the shell
   

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4. >>> from gpiozero import *
   >>> th = TrafficHat()
   >>> th.lights.on()
   >>> th.lights.blink()
   >>> th.buzzer.on()
   >>> th.buzzer.off()
   >>> th.button.when_pressed = th.on
   >>> th.button.when_released = th.off
   

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5. Source/values
   >>> th.lights.green.value
   False
   >>> th.button.value
   False
   >>> th.button.value
   True
   >>> th.lights.green.source = th.button.values
   

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6. GPIO Zero pin factories
   ●
   GPIO Zero allows use with various pin libraries:
   – RPi.GPIO (default)
   – RPIO
   – pigpio
   – Native
   – Mock
   ●
   You can select one to use at launch
   ●
   Or you can change on the fly!
   

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7. pigpio
   ●
   Pin library implemented in C
   ●
   Runs as a daemon as root
   ●
   You can communicate to it with sockets (without root)
   ●
   Lots of advanced GPIO features built-in
   ●
   Accepts socket requests over the network, allowing remote
   GPIO capabilities
   ●
   Remote GPIO works between two Pis, or from PC to Pi
   

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8. Close Thonny and open a Terminal
   

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9. Start the pigpio daemon
   $ sudo pigpiod
   

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10. Find your IP address
    $ hostname -I
    

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11. Launch Thonny with another Pi’s IP address
    $ GPIOZERO_PIN_FACTORY=pigpio
    PIGPIO_ADDR=10.3.12.117 thonny&
    

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12. Connect to the remote Traffic HAT
    >>> from gpiozero import *
    >>> th = TrafficHat()
    >>> th.pin_factory
    
    >>> th.lights.blink()
    

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13. Examples!
    

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14. AND logic gate
    # launch with remote Pi’s IP address as default pin factory
    from gpiozero import Button, LED
    from gpiozero.pins.rpigpio import RPiGPIOFactory
    from gpiozero.tools import all_values
    local = RPiGPIOFactory()
    other_led = LED(22) # remote
    other_btn = Button(25) # remote
    my_btn = Button(25, pin_factory=local) # local
    other_led.source = all_values(my_btn.values, other_btn.values)
    

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15. OR logic gate
    # launch with remote Pi’s IP address as default pin factory
    from gpiozero import Button, LED
    from gpiozero.pins.rpigpio import RPiGPIOFactory
    from gpiozero.tools import any_values
    local = RPiGPIOFactory()
    other_led = LED(22) # remote
    other_btn = Button(25) # remote
    my_btn = Button(25, pin_factory=local) # local
    other_led.source = any_values(my_btn.values, other_btn.values)
    

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16. PingServer
    from gpiozero import TrafficHat, PingServer
    from gpiozero.tools import negated
    th = TrafficHat()
    ps = PingServer(‘10.3.15.15’)
    th.lights.green.source = ps.values
    th.lights.red.source = negated(ps.values)
    

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17. CPUTemperature
    from gpiozero import LEDBarGraph, CPUTemperature
    leds = LEDBarGraph(22, 23, 24, pwm=True)
    cpu = CPUTemperature(min_temp=40, max_temp=70)
    print(cpu.temperature)
    leds.source = cpu.values
    

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18. CPUTemperature buzzer
    from gpiozero import PWMOutputDevice, CPUTemperature
    buzzer = PWMOutputDevice(5)
    cpu = CPUTemperature(min_temp=40, max_temp=70)
    print(cpu.temperature)
    buzzer.source = cpu.values
    

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19. Multi-room motion alert
    from gpiozero import LEDBoard, MotionSensor
    from gpiozero.pins.pigpio import PiGPIOFactory
    from signal import pause
    ips = ['192.168.1.3', '192.168.1.4', '192.168.1.5', '192.168.1.6']
    remotes = [PiGPIOFactory(host=ip) for ip in ips]
    leds = LEDBoard(2, 3, 4, 5) # leds on this pi
    sensors = [MotionSensor(17, pin_factory=r) for r in remotes] # remote sensors
    for led, sensor in zip(leds, sensors):
    led.source = sensor.values
    pause()
    

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20. Multi-room doorbell
    from gpiozero import LEDBoard, MotionSensor
    from gpiozero.pins.pigpio import PiGPIOFactory
    from signal import pause
    ips = ['192.168.1.3', '192.168.1.4', '192.168.1.5', '192.168.1.6']
    remotes = [PiGPIOFactory(host=ip) for ip in ips]
    button = Button(17) # button on this pi
    buzzers = [Buzzer(pin, pin_factory=r) for r in remotes] # buzzers on remote pins
    for buzzer in buzzers:
    buzzer.source = button.values
    pause()
    

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21. Sense HAT
    from gpiozero import LightSensor
    from gpiozero.pins.pigpio import PiGPIOFactory
    from sense_hat import SenseHat
    factory = PiGPIOFactory(host='192.168.1.4')
    light = LightSensor(4, pin_factory=factory)) # remote motion sensor
    sense = SenseHat() # local sense hat
    blue = (0, 0, 255)
    yellow = (255, 255, 0)
    while True:
    if light.value > 0.5:
    sense.clear(yellow)
    else:
    sense.clear(blue)
    

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22. Remote button robot
    from gpiozero import Button, Robot
    from gpiozero.pins.pigpio import PiGPIOFactory
    factory = PiGPIOFactory(host='192.168.1.17')
    robot = Robot(left=(4, 14), right=(17, 18), pin_factory=factory) # remote pins
    # local buttons
    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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23. Remote pot robot
    from gpiozero import Robot, MCP3008
    robot = Robot(left=(4, 14), right=(17, 18))
    left = MCP3008(0)
    right = MCP3008(1)
    robot.source = zip(left.values, right.values)
    

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24. Remote pot robot
    from gpiozero import Robot, MCP3008
    from gpiozero.tools import scaled
    robot = Robot(left=(4, 14), right=(17, 18))
    left = MCP3008(0)
    right = MCP3008(1)
    robot.source = zip(scaled(left.values, -1, 1), scaled(right.values, -1, 1))
    

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25. What can you control remotely?
    ●
    Pi with LEDs showing who is home (ping known mobile phone
    IP addresses)
    ●
    Pi with LEDs showing sensor data from other rooms
    ●
    Pi with LEDs showing data from the internet (e.g. tube line info)
    ●
    Control robot remotely from your PC
    ●
    Use two HATs at once
    ●
    Run the same script on multiple Pis from one control PC
    

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