Merge pull request adafruit#194 from Palmstroemen/patch-1

Added comments for pins used on different boards

Author: ladyada

examples/ssd1306_128x32_i2c/ssd1306_128x32_i2c.ino

@@ -27,6 +27,10 @@
 #define SCREEN_HEIGHT 32 // OLED display height, in pixels
 
 // Declaration for an SSD1306 display connected to I2C (SDA, SCL pins)
+// The pins for I2C are defined by the Wire-library. 
+// On an arduino UNO:       A4(SDA), A5(SCL)
+// On an arduino MEGA 2560: 20(SDA), 21(SCL)
+// On an arduino LEONARDO:   2(SDA),  3(SCL), ...
 #define OLED_RESET     4 // Reset pin # (or -1 if sharing Arduino reset pin)
 Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET);