diff --git a/PID_Timed.h b/PID_Timed.h
index 5a8f39a..aff4467 100644
--- a/PID_Timed.h
+++ b/PID_Timed.h
@@ -1,5 +1,4 @@
-#ifndef PID_Timed_h
-#define PID_Timed_h
+#pragma once
 #define LIBRARY_VERSION	1.1.1
 
 class PID
@@ -9,10 +8,14 @@ class PID
   public:
 
   //Constants used in some of the functions below
-  #define DIRECT  0
-  #define REVERSE  1
-  #define P_ON_M 0
-  #define P_ON_E 1
+  //#define DIRECT  0
+  //#define REVERSE  1
+  //#define P_ON_M 0
+  //#define P_ON_E 1
+	static const int8_t DIRECT = 0;
+	static const int8_t REVERSE = 1;
+	static const int8_t P_ON_M = 0;
+	static const int8_t P_ON_E = 1;
 
   //commonly used functions **************************************************************************
     PID(double*, double*, double*,        // * constructor.  links the PID to the Input, Output, and 
@@ -80,5 +83,4 @@ class PID
 	double ReferenceSampleTime;
 	double outMin, outMax;
 	bool inAuto, pOnE;
-};
-#endif
+};
\ No newline at end of file
diff --git a/README.md b/README.md
index 40177b9..5be6f36 100644
--- a/README.md
+++ b/README.md
@@ -21,7 +21,7 @@ double Setpoint, Input, Output;
 
 //Specify the links and initial tuning parameters
 double Kp=2, Ki=5, Kd=1;
-PID myPID(&Input, &Output, &Setpoint, Kp, Ki, Kd, 0.03, DIRECT); // 30 msec target average sampling rate
+PID myPID(&Input, &Output, &Setpoint, Kp, Ki, Kd, 0.03, PID::DIRECT); // 30 msec target average sampling rate
 
 void setup()
 {
diff --git a/examples/PID_Basic/PID_Basic.ino b/examples/PID_Basic/PID_Basic.ino
index d910592..e721a99 100644
--- a/examples/PID_Basic/PID_Basic.ino
+++ b/examples/PID_Basic/PID_Basic.ino
@@ -13,7 +13,7 @@ double Setpoint, Input, Output;
 
 //Specify the links and initial tuning parameters
 double Kp=2, Ki=5, Kd=1;
-PID myPID(&Input, &Output, &Setpoint, Kp, Ki, Kd, 0.03, DIRECT); // 30 msec target average sampling rate
+PID myPID(&Input, &Output, &Setpoint, Kp, Ki, Kd, 0.03, PID::DIRECT); // 30 msec target average sampling rate
 
 void setup()
 {
diff --git a/library.properties b/library.properties
index 8b017ae..68e3c0b 100644
--- a/library.properties
+++ b/library.properties
@@ -1,5 +1,5 @@
 name=PID_Timed
-version=1.0.1
+version=1.1.0
 author=Ilia O., Brett Beauregard 
 maintainer=Ilia O.
 sentence=PID controller with non-uniform time sampling