Getting started with the Python picamera library including wiring up a GPIO push button

1. Getting started with
Python picamera
@ben_nuttall

2. Connect your Camera

3. Boot the Pi and log in

4. Test the camera
Type raspistill -k and hit Enter
This starts the camera preview
Hit Ctrl + C to stop

5. Take a selfie!
Type raspistill -o image.jpg and hit Enter
raspistill is the command for using the camera
-o means “output”
image.jpg is the chosen filename

6. Check the photo is there
Run ls to see the photo is there
Run startx to boot to Desktop

7. Open File Manager

8. Open image
Double click image.jpg to view it

9. Open Terminal

10. Open IDLE as root
Type sudo idle3 & and hit Enter
sudo means super user do
IDLE is a Python application
& means open in a new process

11. New file
Go to File > New window
Save as camera.py

12. Take a selfie with Python
from picamera import PiCamera
from time import sleep
with PiCamera() as camera:
camera.start_preview()
sleep(5)
camera.capture('/home/pi/image2.jpg')
camera.stop_preview()
Press F5 to run

13. View the photo from File Manager
Notice the difference in resolution between the file taken
from the command line and from Python
This is due to default settings in raspistill and in Python
picamera
Resolution and other aspects are configurable

14. GPIO pins

15. GPIO pins

16. Breadboard

17. Connect a GPIO push button

18. Add the button to the code
from picamera import PiCamera
from time import sleep
from RPi import GPIO
button = 17
GPIO.setmode(GPIO.BCM)
GPIO.setup(button, GPIO.IN, GPIO.PUD_UP)
with PiCamera() as camera:
camera.start_preview()
GPIO.wait_for_edge(button, GPIO.FALLING)
camera.capture('/home/pi/image3.jpg')
camera.stop_preview()

19. Press the button to take a picture
Run the script with F5
Wait for the preview
Press the push button to take a picture

20. View the photo from File Manager

21. Add a loop
with PiCamera() as camera:
camera.start_preview()
GPIO.wait_for_edge(button, GPIO.FALLING)
for i in range(5):
sleep(3)
camera.capture('/home/pi/picture%s.jpg' % i)
camera.stop_preview()

22. What’s the difference?
GPIO.wait_for_edge(button, GPIO.FALLING)
for i in range(5):
sleep(3)
camera.capture('/home/pi/picture%s.jpg' % i)
camera.stop_preview()
for i in range(5):
GPIO.wait_for_edge(button, GPIO.FALLING)
sleep(3)
camera.capture('/home/pi/picture%s.jpg' % i)
camera.stop_preview()

23. What can you do?

24. Raspberry Pi Camera Resources

25. Raspberry Pi Resources