From 0b82b120c5eeb0d83d75ee4effd043bd96ff7304 Mon Sep 17 00:00:00 2001
From: Josh Stewart <josh@noisymime.org>
Date: Fri, 27 May 2016 22:44:40 +1000
Subject: [PATCH] Fix for reverse PWM IAC valve setting not working

---
 idle.ino | 34 ++++++++++++++++++++++++++--------
 math.h   |  2 +-
 2 files changed, 27 insertions(+), 9 deletions(-)

diff --git a/idle.ino b/idle.ino
index 0baf584c..887bf144 100644
--- a/idle.ino
+++ b/idle.ino
@@ -243,20 +243,38 @@ ISR(TIMER4_COMPC_vect)
 {
   if (idle_pwm_state)
   {
-    *idle_pin_port &= ~(idle_pin_mask);  // Switch pin to low (1 pin mode)
-    if(configPage4.iacChannels) { *idle2_pin_port |= (idle2_pin_mask); } //If 2 idle channels are in use, flip idle2 to be the opposite of idle1
+    if (configPage4.iacPWMdir == 0) 
+    { 
+      //Normal direction
+      *idle_pin_port &= ~(idle_pin_mask);  // Switch pin to low (1 pin mode)
+      if(configPage4.iacChannels) { *idle2_pin_port |= (idle2_pin_mask); } //If 2 idle channels are in use, flip idle2 to be the opposite of idle1
+    }
+    else
+    {
+      //Reversed direction
+      *idle_pin_port |= (idle_pin_mask);  // Switch pin high
+      if(configPage4.iacChannels) { *idle2_pin_port &= ~(idle2_pin_mask); } //If 2 idle channels are in use, flip idle2 to be the opposite of idle1
+    }
     OCR4C = TCNT4 + (idle_pwm_max_count - idle_pwm_cur_value);
-    if (configPage4.iacPWMdir == 0) { idle_pwm_state = false; }
-    else { idle_pwm_state = true; }
+    idle_pwm_state = false; 
   }
   else
   {
-    *idle_pin_port |= (idle_pin_mask);  // Switch pin high
-    if(configPage4.iacChannels) { *idle2_pin_port &= ~(idle2_pin_mask); } //If 2 idle channels are in use, flip idle2 to be the opposite of idle1
+    if (configPage4.iacPWMdir == 0) 
+    { 
+      //Normal direction
+      *idle_pin_port |= (idle_pin_mask);  // Switch pin high
+      if(configPage4.iacChannels) { *idle2_pin_port &= ~(idle2_pin_mask); } //If 2 idle channels are in use, flip idle2 to be the opposite of idle1
+    }
+    else
+    {
+      //Reversed direction
+      *idle_pin_port &= ~(idle_pin_mask);  // Switch pin to low (1 pin mode)
+      if(configPage4.iacChannels) { *idle2_pin_port |= (idle2_pin_mask); } //If 2 idle channels are in use, flip idle2 to be the opposite of idle1
+    }
     OCR4C = TCNT4 + idle_pwm_target_value;
     idle_pwm_cur_value = idle_pwm_target_value;
-    if (configPage4.iacPWMdir == 0) { idle_pwm_state = true; } 
-    else { idle_pwm_state = false; }
+    idle_pwm_state = true; 
   }
     
 }
diff --git a/math.h b/math.h
index 8577a84b..81af51a9 100644
--- a/math.h
+++ b/math.h
@@ -76,7 +76,7 @@ unsigned long divu100(unsigned long n) {
 //This is a relatively fast approximation of a percentage value. 
 unsigned long percentage(byte x, unsigned long y)
 {
-  return divu100(y) * x;
+  return divu100(y * x);
 }
 
 #endif // MATH_H