From 8b95fe891afcc89ebcf85ad085d881f99f7fa5bd Mon Sep 17 00:00:00 2001
From: Josh Stewart <josh@noisymime.org>
Date: Thu, 27 Oct 2016 07:03:42 +1100
Subject: [PATCH] Improved fan on/off logic

---
 auxiliaries.ino | 17 ++++++++++++-----
 globals.h       |  1 +
 2 files changed, 13 insertions(+), 5 deletions(-)

diff --git a/auxiliaries.ino b/auxiliaries.ino
index 17e46735..2d3acbed 100644
--- a/auxiliaries.ino
+++ b/auxiliaries.ino
@@ -10,15 +10,22 @@ Fan control
 */
 void initialiseFan()
 {
-if(configPage4.fanInv == 1) {fanHIGH = LOW, fanLOW = HIGH; }
-else {fanHIGH = HIGH, fanLOW = LOW;}
-digitalWrite(pinFan, fanLOW);         //Initiallise program with the fan in the off state
+  if(configPage4.fanInv) { fanHIGH = LOW, fanLOW = HIGH; }
+  else { fanHIGH = HIGH, fanLOW = LOW; }
+  digitalWrite(pinFan, fanLOW);         //Initiallise program with the fan in the off state
+  currentStatus.fanOn = false;
 }
 
 void fanControl()
 {
-   if (currentStatus.coolant >= (configPage4.fanSP - CALIBRATION_TEMPERATURE_OFFSET)) { digitalWrite(pinFan,fanHIGH); }
-   else if (currentStatus.coolant <= (configPage4.fanSP - configPage4.fanHyster)) { digitalWrite(pinFan, fanLOW); }
+  if(configPage4.fanEnable)
+  {
+    int onTemp = (int)configPage4.fanSP - CALIBRATION_TEMPERATURE_OFFSET;
+    int offTemp = onTemp - configPage4.fanHyster;
+    
+    if (!currentStatus.fanOn && currentStatus.coolant >= onTemp) { digitalWrite(pinFan,fanHIGH); currentStatus.fanOn = true; }
+    if (currentStatus.fanOn && currentStatus.coolant <= offTemp) { digitalWrite(pinFan, fanLOW); currentStatus.fanOn = false; }
+  }
 }
 
 #if defined(__AVR_ATmega1280__) || defined(__AVR_ATmega2560__)
diff --git a/globals.h b/globals.h
index a7f2006e..1c753a83 100644
--- a/globals.h
+++ b/globals.h
@@ -139,6 +139,7 @@ struct statuses {
   byte launchCorrection; //The amount of correction being applied if launch control is active
   byte afrTarget;
   byte idleDuty;
+  bool fanOn; //Whether or not the fan is turned on
   byte flex; //Ethanol reading (if enabled). 0 = No ethanol, 100 = pure ethanol. Eg E85 = 85. 
   unsigned long TAEEndTime; //The target end time used whenever TAE is turned on
   volatile byte squirt;