Raspberry Pi workshop with Picamera, Flask and the Twitter API

1. Raspberry Pi
Creative Technologists
Sheffield
July 2015

2. Self-directed workshop
● Use the Terminal (command line interface)
● Install software (apt and pip)
● Use the web browser (that's where the good stuff is)
● Use GitHub (download projects, upload your own)
● Use APIs (Application Programming Interfaces)
● Ask questions!
● Take notes!
● Expand your understanding!
● Ask for help!

3. Connect the camera

4. Boot the Pi and log in

5. Test the camera
● raspistill -k
● If it doesn't work, is your camera connected correctly?
● Is your camera enabled?
– sudo raspi-config
– Enable camera
● Press Ctrl + C to exit the preview

6. Browse my project on GitHub
● Open the web browser
● Go to https://github.com/bennuttall/bett-bot
● Read the instructions
● Do the instructions:
– Install pip
– Install flask
– Download the repo
– Install twython

7. Run the app
● Enter the bett-bott folder
– cd bett-bott
● Run the app
– python app.py
● Open 127.0.0.1:5000 in the web browser
● Click Capture to take a photo
● See the photo in the gallery
● Click the photo
● Take more photos
●
Find your IP address (e.g. 192.168.1.8)
– hostname -I
● Browse to http://192.168.1.8:5000 on your phone/tablet/laptop

8. Connect to Twitter
● Log in to www.twitter.com in the web browser (or sign up)
● Go to apps.twitter.com
– Create new app
– Set permissions to read and write
– Generate access tokens
(see Tweeting Babbage resource on raspberrypi.org for
detailed instructions)
– raspberrypi.org/learning/tweeting-babbage/worksheet/

9. Add your API keys
● Open auth.py with Python/IDLE
● Add your keys
– consumer_key
– consumer_secret
– access_token
– access_token_secret
● Run the app again
– Open Terminal
– cd bett-bot-master
– python app.py
● Now you can tweet the pictures

10. Look at the code
● Open app.py with Python/IDLE
● What's it doing?
– Imports
– Try/except
– Connect to Twitter
– Define routes
● /
● /capture/
● /view/
● /tweet/
– Routes refer to HTML templates
– Run Flask app

11. Hack it
● Change the appearance
● Add a feature
● Think about more to do later – ideas?
● Is a web app suitable?
● What's possible? What's not?
● Think about hardware installation
● Think about touch screens