From 20199df2172880ae5a6009011e484e707dd708ee Mon Sep 17 00:00:00 2001
From: Brett Beauregard <br3ttb@gmail.com>
Date: Sun, 18 Dec 2011 08:28:52 -0500
Subject: [PATCH] in the Compute() function, timeChange is now declared as
 "unsigned long"

formerly, if left in manual mode for a long time (e.g. during an autotune,)
 the "int" timeChange would wrap causeing the PID not to calculate for an
unacceptable period of time.
---
 PID_v1/PID_v1.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/PID_v1/PID_v1.cpp b/PID_v1/PID_v1.cpp
index fa67494..a5a76ae 100644
--- a/PID_v1/PID_v1.cpp
+++ b/PID_v1/PID_v1.cpp
@@ -46,7 +46,7 @@ void PID::Compute()
 {
    if(!inAuto) return;
    unsigned long now = millis();
-   int timeChange = (now - lastTime);
+   unsigned long timeChange = (now - lastTime);
    if(timeChange>=SampleTime)
    {
       /*Compute all the working error variables*/