GPIO Zero - AmsterJam

GPIO Zero talk given at 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