From e602c28ad975f2c0cb575509c99d13dcd35dff69 Mon Sep 17 00:00:00 2001
From: Scott Lahteine <sourcetree@thinkyhead.com>
Date: Tue, 9 Jun 2015 16:54:28 -0700
Subject: [PATCH 1/2] Set auto fan pins to OUTPUT during init

Fixes the problem of these pins being left in INPUT state, as described
in #1497
---
 Marlin/temperature.cpp | 14 +++++++++++++-
 1 file changed, 13 insertions(+), 1 deletion(-)

diff --git a/Marlin/temperature.cpp b/Marlin/temperature.cpp
index edbab7f19d..25ec3887c8 100644
--- a/Marlin/temperature.cpp
+++ b/Marlin/temperature.cpp
@@ -374,7 +374,6 @@ void setExtruderAutoFanState(int pin, bool state)
 {
   unsigned char newFanSpeed = (state != 0) ? EXTRUDER_AUTO_FAN_SPEED : 0;
   // this idiom allows both digital and PWM fan outputs (see M42 handling).
-  pinMode(pin, OUTPUT);
   digitalWrite(pin, newFanSpeed);
   analogWrite(pin, newFanSpeed);
 }
@@ -918,6 +917,19 @@ void tp_init() {
     ANALOG_SELECT(FILWIDTH_PIN);
   #endif
   
+  #if HAS_AUTO_FAN_0
+    pinMode(EXTRUDER_0_AUTO_FAN_PIN, OUTPUT);
+  #endif
+  #if HAS_AUTO_FAN_1 && (EXTRUDER_1_AUTO_FAN_PIN != EXTRUDER_0_AUTO_FAN_PIN)
+    pinMode(EXTRUDER_1_AUTO_FAN_PIN, OUTPUT);
+  #endif
+  #if HAS_AUTO_FAN_2 && (EXTRUDER_2_AUTO_FAN_PIN != EXTRUDER_0_AUTO_FAN_PIN) && (EXTRUDER_2_AUTO_FAN_PIN != EXTRUDER_1_AUTO_FAN_PIN)
+    pinMode(EXTRUDER_2_AUTO_FAN_PIN, OUTPUT);
+  #endif
+  #if HAS_AUTO_FAN_3 && (EXTRUDER_3_AUTO_FAN_PIN != EXTRUDER_0_AUTO_FAN_PIN) && (EXTRUDER_3_AUTO_FAN_PIN != EXTRUDER_1_AUTO_FAN_PIN) && (EXTRUDER_3_AUTO_FAN_PIN != EXTRUDER_2_AUTO_FAN_PIN)
+    pinMode(EXTRUDER_3_AUTO_FAN_PIN, OUTPUT);
+  #endif
+
   // Use timer0 for temperature measurement
   // Interleave temperature interrupt with millies interrupt
   OCR0B = 128;

From 1d94d098bf27bdfcaf18988e20bb18507acb50ce Mon Sep 17 00:00:00 2001
From: Scott Lahteine <sourcetree@thinkyhead.com>
Date: Tue, 9 Jun 2015 17:01:47 -0700
Subject: [PATCH 2/2] Formatting tweaks as part of fixing issue 1497

---
 Marlin/temperature.cpp | 10 ++++------
 1 file changed, 4 insertions(+), 6 deletions(-)

diff --git a/Marlin/temperature.cpp b/Marlin/temperature.cpp
index 25ec3887c8..48a3085068 100644
--- a/Marlin/temperature.cpp
+++ b/Marlin/temperature.cpp
@@ -370,16 +370,14 @@ int getHeaterPower(int heater) {
 
 #if HAS_AUTO_FAN
 
-void setExtruderAutoFanState(int pin, bool state)
-{
+void setExtruderAutoFanState(int pin, bool state) {
   unsigned char newFanSpeed = (state != 0) ? EXTRUDER_AUTO_FAN_SPEED : 0;
   // this idiom allows both digital and PWM fan outputs (see M42 handling).
   digitalWrite(pin, newFanSpeed);
   analogWrite(pin, newFanSpeed);
 }
 
-void checkExtruderAutoFans()
-{
+void checkExtruderAutoFans() {
   uint8_t fanState = 0;
 
   // which fan pins need to be turned on?      
@@ -442,7 +440,7 @@ void checkExtruderAutoFans()
   #endif
 }
 
-#endif // any extruder auto fan pins set
+#endif // HAS_AUTO_FAN
 
 //
 // Temperature Error Handlers
@@ -916,7 +914,7 @@ void tp_init() {
   #if HAS_FILAMENT_SENSOR
     ANALOG_SELECT(FILWIDTH_PIN);
   #endif
-  
+
   #if HAS_AUTO_FAN_0
     pinMode(EXTRUDER_0_AUTO_FAN_PIN, OUTPUT);
   #endif