added note about the pins

rambo · Feb 15, 2012 · 8a6ec64 · 8a6ec64
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 # Arduino I2C master library
 
 A better I2C master library, originally by Wayne Truchsess. See http://dsscircuits.com/articles/arduino-i2c-master-library.html
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+On most Arduino boards, SDA (data line) is on analog input pin 4, and SCL (clock line) is on analog input pin 5. On the Arduino Mega, SDA is digital pin 20 and SCL is 21. (source: http://arduino.cc/it/Reference/Wire)