Fan fix for Panelolu2+Sanguinololu.

Marlin/pins.h

@@ -492,7 +492,7 @@
         #define SDSS 53
         #define SDCARDDETECT -1
         #define KILL_PIN 41
-        #define FAN_PIN 45
+              
       #else
         //arduino pin which triggers an piezzo beeper
         #define BEEPER 33  // Beeper on AUX-4
@@ -907,7 +907,7 @@
 
 #ifdef MELZI
  #define LED_PIN            27 /* On some broken versions of the Sanguino libraries the pin definitions are wrong, which then needs LED_PIN as pin 28. But you better upgrade your Sanguino libraries! See #368. */
-#define FAN_PIN            4
+ #define FAN_PIN            4 // Works for Panelolu2 too
 #endif
 
 #ifdef STB
@@ -935,6 +935,10 @@
  #define Z_ENABLE_PIN       26
  #define E0_ENABLE_PIN      14
 
+ #ifdef LCD_I2C_PANELOLU2
+   #define FAN_PIN          4 // Uses Transistor1 (PWM) on Panelolu2's Sanguino Adapter Board to drive the fan
+ #endif
+
 #else
 
 #define HEATER_BED_PIN      14  // (bed)