attachInterrupt()
http://arduino.cc/en/Reference/AttachInterrupt#.UwzskeN_t8E
SPI
http://tronixstuff.com/2011/05/13/tutorial-arduino-and-the-spi-bus/
D9 to CS (yes, D9, not D14 aka the SS pin, more on that later)
D15 to SCLK
D16 to MOSI
D17 to MISO
3v3 to 3v3 (yes, not to VIN, more on that later)
GND to GND
https://forum.sparkfun.com/viewtopic.php?f=14&t=36982
https://forum.sparkfun.com/viewtopic.php?t=36982&user_select=48246