https://github.com/electricmango/Arduino-Music-Project/blob/master/A_Theme___Tetris_with_Bass/A_Theme___Tetris_with_Bass.ino
http://www.technoblogy.com/show?QBB		<---- this is really clever
https://code.google.com/p/arduino-tiny/
http://www.instructables.com/id/Soft-Latch-Power-Switch-Ardweeny/
http://www.eeherald.com/section/design-guide/esmod12.html
 Digital Potentiometer 
 https://learn.sparkfun.com/tutorials/serial-peripheral-interface-spi
 http://www.eeherald.com/section/design-guide/esmod12.html
 http://www.best-microcontroller-projects.com/spi-interface.html
 http://www.atmel.com/products/memories/serial/default.aspx
 http://electronics.stackexchange.com/questions/5188/help-with-device-identification-in-a-chain/10537#10537
 http://www.societyofrobots.com/member_tutorials/book/export/html/35
 http://www.maximintegrated.com/en/app-notes/index.mvp/id/4024
 https://learn.sparkfun.com/tutorials/i2c?_ga=1.84666257.926338635.1395348980
 https://learn.sparkfun.com/tutorials/serial-peripheral-interface-spi
http://www.atmel.com/products/memories/serial/default.aspx

http://www.avr-asm-tutorial.net/avr_en/
http://www.avrbeginners.net/
http://usethearduino.blogspot.co.nz/2009/08/programming-attiny13-in-assembly.html
http://www.avrbeginners.net/getting_started/starter_2_2.html
http://fabacademy.org/archives/2014/students/zitek.scott/week8.html
http://wiki.fablab.is/wiki/Hello_world_electronics#RGB_LED

http://www.ernstc.dk/arduino/tinycom.html
http://playground.arduino.cc/Code/ShiftRegSN74HC165N

philip
http://www.maximintegrated.com/en/app-notes/index.mvp/id/4037


prices
http://www.digikey.co.nz/product-detail/en/CD74HC165MT/296-32058-1-ND/3505826