Python and Raspberry Pi - FOSDEM 2017

Talk on Python and Raspberry Pi at FOSDEM 2017

Transcript

1. Python and Raspberry Pi Ben Nuttall Raspberry Pi Foundation UK Charity 1129409
2. Ben Nuttall • Raspberry Pi Community Manager • Based in Cambridge, UK • Creator of gpiozero python library • Columnist on opensource.com • github.com/bennuttall • twitter.com/ben_nuttall • ben@raspberrypi.org
3. Over 11 million Raspberry Pis sold
4. Raspberry Pi Foundation • Educational charity founded in 2009 • Owns trading subsidiary Raspberry Pi Trading Ltd • Trading profits fund educational programmes
5. Our mission “Putting the power of digital making into the hands of people all over the world” So that people are: • Capable of understanding and shaping an increasingly digital world • Able to solve the problems that matter to them, both as makers and entrepreneurs • Equipped for the jobs of the future
6. We do this by providing... • Low-cost, high-performance computers • Outreach and education programmes • Free resources and teacher training p
7. Current models • Raspberry Pi 3 • 64-bit quad-core ARMv8 @ 1.2GHz • 1GB RAM • $35 • Raspberry Pi Zero • 32-bit single-core ARMv6 @ 1GHz • 512MB RAM • $5
8. Raspbian Jessie with PIXEL
9. PIXEL x86
10. GPIO Pins – General Purpose Input/Output
11. Physical computing • Flashy lights • Motors & robots • Photo & video • Sensors • Internet of Things • Engaging and empowering
12. GPIO • 3V3, 5V • GPIO, SPI, I2C, UART • GPIO = variable 3V3
13. GPIO components
14. Add-on boards / HATs
15. Python - RPi.GPIO import RPi.GPIO as GPIO from time import sleep GPIO.setmode(GPIO.BCM) GPIO.setwarnings(False) GPIO.setup(17, GPIO.OUT) while True: GPIO.output(17, GPIO.HIGH) sleep(1) GPIO.output(17, GPIO.LOW) sleep(1)
16. Python - GPIO Zero from gpiozero import LED from time import sleep led = LED(17) while True: led.on() sleep(1) led.off() sleep(1)
17. Python - GPIO Zero from gpiozero import LED led = LED(17) led.blink()
18. 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()
19. 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
20. Multi-paradigm: declarative from gpiozero import LED, Button led = LED(17) button = Button(4) led.source = button.values
21. GPIO Zero supports...
22. GPIO Zero Device Hierarchy!
23. 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
24. pigpio - remote GPIO from Pi or PC
25. pigpio - remote GPIO from Pi or PC from gpiozero import LED from gpiozero.pins.pigpiod import PiGPIOPin led = LED(PiGPIOPin(22, host='192.168.0.2')) led.blink()
26. 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()
27. Picamera • 8 megapixels (v2) – v1 was 5mpx • Visible light & infra-red versions available • 1080p30, 720p60 and VGA90 video • Command line interface and Python library
28. Picamera - capture from picamera import PiCamera from time import sleep camera = PiCamera() camera.start_preview() sleep(3) camera.capture('/home/pi/Desktop/image.jpg') camera.stop_preview()
29. Picamera – record video from picamera import PiCamera from time import sleep camera = PiCamera() camera.start_preview() camera.start_recording('/home/pi/video.h264') sleep(10) camera.stop_recording() camera.stop_preview()
30. Picamera + GPIO push button from picamera import PiCamera from gpiozero import Button camera = PiCamera() button = Button(17) camera.start_preview() button.wait_for_press() camera.capture('/home/pi/Desktop/image.jpg') camera.stop_preview()
31. Picamera image effects from picamera import PiCamera from time import sleep camera = PiCamera() camera.start_preview() for effect in camera.IMAGE_EFFECTS: camera.image_effect = effect camera.annotate_text = "Effect: %s" % effect sleep(5) camera.stop_preview()
32. Picamera image effects
33. Web Streaming
34. Energenie
35. Energenie tortoise lamp from gpiozero import Energenie, TimeOfDay from datetime import time lamp = Energenie(1) daytime = TimeOfDay(time(8), time(20)) lamp.source = daytime.values
36. Sense HAT • Special made for Tim Peake's Astro Pi mission • Sensors, LED display & joystick • Great for science, games and creativity • Works on any Pi model • Emulators also available
37. Sense HAT
38. Sense HAT >>> from sense_hat import SenseHat >>> sense = SenseHat() >>> sense.show_message(“Hello world”) >>> sense.temperature >>> sense.humidity >>> sense.accelerometer >>> sense.gyroscope >>> sense.orientation
39. Sense HAT from sense_hat import SenseHat sense = SenseHat() while True: r = 255 * sense.humidity / 100 sense.clear(r, 0, 0)
40. Astro Pi: Your code in space
41. Sense HAT Web Emulator
42. Sense HAT Desktop Emulator
43. Read the docs! • gpiozero.readthedocs.io • picamera.readthedocs.io • pythonhosted.org/sense-hat
44. How you can get involved...
45. Python libraries • Contribute to: – gpiozero – picamera – sense hat – more! • Help maintainers upgrade modules to Python 3 • Create your own Python libraries for Raspberry Pi things
46. The MagPi • Community magazine established in 2012 (as free PDF download) • Now the official Raspberry Pi magazine • Paper copies on sale in UK/US shops and online • Still a free PDF download • Occasionally comes with a free computer • Book series (also available for free) • raspberrypi.org/magpi
47. Raspberry Jam • Independently organised community events • Family-friendly • Mix of meetup / conference / workshop styles • Contact me about setting one up! • raspberrypi.org/jam
48. Code Club • Free volunteer-led after school clubs for children • Projects provided using Scratch, HTML and Python • Training and support provided for volunteers • Help translating materials • codeclubworld.org
49. Python and Raspberry Pi Ben Nuttall Raspberry Pi Foundation UK Charity 1129409