Facebook Summer of Hack NYC 2012 - face(book)^2

Event Info: https://www.facebook.com/events/100370656773845/

The premise of face(book)^2:
face(book)^2 is a physical implementation of facebook. It is, quite literally, a facebook book. We built electronics into a large book and pulled data from the facebook api via a python script running on a computer connected wirelessly to our book via a wireless serial XBEE link.

Created by:

• Jeremy Blum (https://www.github.com/sciguy14)
• Jason Wright (https://github.com/jpwright)

Book Hardware Contents

• One large 16x2 Character Display for showing context-relevant title information
• Three 16x4 Character Displays for showing recent feed updates, post comments, etc
• A monochrome LCD from an old Nokia Cell phone for displaying low-res bitmap versions of profile pics and favicons
• An accelerometer for detecting a "page turn" motion for flipping through the newfeed data
• Three pushbuttons for selecting to show details of a particular 16x4 LCD
• 4 Trimpots for adjusting the contrast of all the character displays
• An Arduino Mega for all the control and processing
• An XBee shield with an Xbee Radio hooked up (in a non-standard fasion) to Serial1 (Serial0 is used for USB Debugging)
• A Level shift for interfacing the monochrome display
• A button for returning to the home screen
• A "like" button for liking or unliking posts from your friends
• A limit switch for detecting when the book is open and putting it to sleep when closed.
• The biggest book that we could find at Barnes and Noble on such short notice

System Operation Scheme

1. Book is opened, triggering release of limit switch
2. MCU says hello to the computer via Xbee
3. User logs into facebook on computer, which authenticates them via OAuth. Username is passed to book for display
4. Book requests the news feed
5. Computer queries user data from facebook API, formats strings, adds special characters, and transmits them back to book
6. Book interprets datastrings and prints appopriately on screens
7. Acceleromters can be used to "turn the page" which cycles newsfeed items
8. User can click button next to each item to expand it, see comments, etc
9. In expanded view, usesr can use a dedicated button to like or dislike items
10. Accelerometer can be used to see additional comments, etc
11. Nokia Display is used to show low-res bitmap version of user avatar

Serial Interface Documentation

• General Syntax
  • All commands start with a '.' character
  • All commands end with a newline '\n' character
  • first character indicates the command
  • followed by comma seperated arguments
  • Computer can only repond to requests from the hardware
  • Arduino responds on executions completed with 'z' ACK character followed the same command char plus a newline
• Special Characters, there is never more than one on a line
  • 0 <l> is like
    
  • 1 <c> is comment
    
  • 2 <p> is place
    
  • 3 <s> is squared
    
  • 4 <u> is link
    
  • 5 <d> is desc [DEPRECATED]
    
  • 6 <e> is ellipsis (...)
    
• From the Hardware
  • Hello = .h\n
  • Request Feed = .f\n
  • Expand Item = .e[feed # to expand]\n
  • Next Item (contextual) = .n\n
  • Previous Item (contextual) = .p\n
  • "Like" Item (contextual) = .l\n
  • Request Graphical Display Contents = .g\n
  • Close = .c\n

• From the Computer

  • Hello ID = .h[String containing User First Name]\n
  • Return Feed Contents = .f[string for display 1],[string for display 2],[etc]...\n
  • Return Expanded View Contents = .e[string for display 1],[string for display 2],[etc]...\n
  • Return Graphical Display Binary Data = .g[binary data string representing all pixels]\n
  • Write a line to a display = .w[display ID char (t,1,2,3)],[display line # char (0,1,2,3),[String of Data]\n

  External Resouces for Arduino

  • Adafruit Graphical LCD Arduino Library: https://github.com/adafruit/Adafruit-PCD8544-Nokia-5110-LCD-library
  • Adafruit GFX Library: https://github.com/adafruit/Adafruit-GFX-Library

  External Resources for Python

  • Facebook Console: https://github.com/facebook/fbconsole
  • SimpleJson Module: https://github.com/simplejson/simplejson
  • pySerial Module: http://pyserial.sourceforge.net/

  LiquidCrystal Arduino Library Mod

  There is known issue with addressing 16x4 LCDS See Here: http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1253367247/6 This fix was applied: int row_offsets[] = { 0x00, 0x40, 0x10, 0x50 }; Note that this will probably prevent 20x4 LCDs from working.