diff --git a/Angle.cpp b/Angle.cpp
index a821fd7..1788650 100644
--- a/Angle.cpp
+++ b/Angle.cpp
@@ -1,12 +1,10 @@
 //
 //    FILE: Angle.cpp
 //  AUTHOR: Rob Tillaart
-// VERSION: 0.1.13
+// VERSION: 0.1.14
 // PURPOSE: library for Angle math for Arduino
 //     URL: https://github.com/RobTillaart/Angle
 //          http://forum.arduino.cc/index.php?topic=339402
-//
-//  HISTORY: see changelog.md
 
 
 #include "Angle.h"
@@ -31,7 +29,6 @@ Angle::Angle(int dd, int mm, int ss, int tt)
     m = mm;
     s = ss;
     t = tt;
-    //  TODO
     //  normalize();
     //  assume only one (largest) parameter is negative at most...
     if (d < 0) { d = -d; neg = true; }
@@ -318,7 +315,7 @@ int Angle::compare(const Angle &a, const Angle &b)
 }
 
 
-void Angle::normalize()  //  TODO CHECK
+void Angle::normalize()
 {
     while (t < 0)      { s--; t += 10000; }
     while (t >= 10000) { s++; t -= 10000; }
diff --git a/Angle.h b/Angle.h
index 8223eef..d0b4cac 100644
--- a/Angle.h
+++ b/Angle.h
@@ -2,9 +2,10 @@
 //
 //    FILE: Angle.h
 //  AUTHOR: Rob Tillaart
-// VERSION: 0.1.13
+// VERSION: 0.1.14
 // PURPOSE: angle library for Arduino
-// HISTORY: See angle.cpp
+//     URL: https://github.com/RobTillaart/Angle
+//          http://forum.arduino.cc/index.php?topic=339402
 //
 // AngleFormat proxy added 03/03/15 by Christoper Andrews.
 //
@@ -15,7 +16,7 @@
 #include "Printable.h"
 
 
-#define ANGLE_LIB_VERSION               (F("0.1.13"))
+#define ANGLE_LIB_VERSION               (F("0.1.14"))
 
 
 class Angle;
@@ -97,5 +98,5 @@ class Angle: public Printable
 };
 
 
-// -- END OF FILE
+//  -- END OF FILE
 
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 3a3eb07..5416332 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -6,6 +6,13 @@ The format is based on [Keep a Changelog](http://keepachangelog.com/)
 and this project adheres to [Semantic Versioning](http://semver.org/).
 
 
+## [0.1.14] - 2023-01-31
+- update GitHub actions
+- update license 2023
+- update readme.md
+- add performance sketch (initial version)
+
+
 ## [0.1.13] - 2022-10-12
 - Add RP2040 support to build-CI
 - Add CHANGELOG.md
diff --git a/README.md b/README.md
index a8c585d..696fa4b 100644
--- a/README.md
+++ b/README.md
@@ -25,17 +25,31 @@ The library implements the Printable interface, allowing one to call
 
 **Serial.println(angle)** or **SD.print(angle)**.
 
+Degree sign ° = ALT-0176 (Windows)
+
+
+#### Related
+
+- https://github.com/RobTillaart/AngleConvertor
+- https://github.com/RobTillaart/AverageAngle
+- https://github.com/RobTillaart/Angle
+- https://github.com/RobTillaart/runningAngle
+
 
 ## Interface
 
-### Constructors
+```cpp
+#include "Angle.h"
+```
+
+#### Constructors
 
 - **Angle(int dd = 0, int mm = 0, int ss = 0, int tt = 0)** create an Angle, default is zero.
 - **Angle(double alpha)** create an Angle from a double.
 - **Angle(char \* str)** create an Angle from a string e.g. "45.31234".
 
 
-### base
+#### Base
 
 - **int sign()** returns -1 or 1.
 - **int degree()** returns # degrees.
@@ -44,19 +58,21 @@ The library implements the Printable interface, allowing one to call
 - **int tenthousand()** returns # ten-thousands of a second.
 
 
-### Conversions
+#### Conversions
 
 - **double toDouble()** returns the angle as a double (0..360.0, float on UNO).
 - **double toRadians()** returns the angle in radians (0..TWO_PI).
 - **void fromRadian(double rad)** create an angle from radians.
 
+More conversions - https://github.com/RobTillaart/AngleConvertor
+
 
-### Equality operators
+#### Equality operators
 
 The library supports equality operator "==", "!=", "<" "<=" ">" and ">=" .
 
 
-### Math operators
+#### Math operators
 
 - **negate** returns -angle.
 - **addition** and **subtract** add angles to angles.
@@ -71,19 +87,33 @@ See examples.
 
 ## Note
 
-The library has not been tested extensively and it could still contain
-bugs. Especially the constructor does not check input so use it carefully.
+The library has not been tested extensively and it could still contain bugs. 
+Especially the constructor does not check input so use it carefully.
 
 
 ## Future
 
+#### Must
+
 - improve documentation
-- test more
-- optimize code where possible
-  - performance sketch
+
+#### Should
+
+- Test normalize code
+  - unit tests, sketch?
+- test more 
+  - TOCHECK in code
 - improve code quality
-  - fix TODO in code
   - use better variable names in code
-  - move all code to .cpp
+
+
+#### Could
+
+- optimize code where possible
+  - low priority
+- move all code to .cpp
+- change output format to confirm standard 4°12'14.1234"
+
+#### Wont
 
 
diff --git a/examples/Angle_performance/Angle_performance.ino b/examples/Angle_performance/Angle_performance.ino
new file mode 100644
index 0000000..d7b0aee
--- /dev/null
+++ b/examples/Angle_performance/Angle_performance.ino
@@ -0,0 +1,268 @@
+//
+//    FILE: Angle_performance.ino
+//  AUTHOR: Rob Tillaart
+// PURPOSE: demo sketch to test angle class
+//     URL: https://github.com/RobTillaart/Angle.git
+//
+
+
+#include "Angle.h"
+
+
+Angle a(1, 2, 3, 4);
+Angle b(45, 30);
+Angle c(2, 3, 4, 5);
+Angle n(0);
+Angle z(5.5);
+
+Angle aa(-1, 2, 3, 45);
+Angle bb(0, -2, 3, 45);
+Angle cc(0, 0, -3, 45);
+Angle dd(0, 0, 0, -45);
+
+uint32_t start, stop;
+
+
+void testConstructors()
+{
+  Serial.println(__FUNCTION__);
+  char str1[] = "-45.987654321";
+
+  delay(100);
+  start = micros();
+  Angle s(str1);
+  stop = micros();
+  Serial.println(stop - start);
+  Serial.println(s);
+
+  delay(100);
+  start = micros();
+  Angle t = str1;
+  stop = micros();
+  Serial.println(stop - start);
+  Serial.println(t);
+
+  Serial.println();
+}
+
+
+void testToDouble()
+{
+  Serial.println(__FUNCTION__);
+
+  delay(100);
+  start = micros();
+  float s = a.toDouble();
+  stop = micros();
+  Serial.println(stop - start);
+  Serial.println(s, 7);
+
+  delay(100);
+  start = micros();
+  s = aa.toDouble();
+  stop = micros();
+  Serial.println(stop - start);
+  Serial.println(s, 7);
+
+  delay(100);
+  start = micros();
+  aa.fromRadians(2 * PI);
+  stop = micros();
+  Serial.println(stop - start);
+  Serial.println(aa);
+
+  Serial.println();
+}
+
+
+void testParts()
+{
+  Serial.println(__FUNCTION__);
+
+  delay(100);
+  start = micros();
+  float s = c.sign();
+  stop = micros();
+  Serial.println(stop - start);
+  Serial.println(s, 7);
+  
+  delay(100);
+  start = micros();
+  s = c.degree();
+  stop = micros();
+  Serial.println(stop - start);
+  Serial.println(s, 7);
+  
+  delay(100);
+  start = micros();
+  s = c.minute();
+  stop = micros();
+  Serial.println(stop - start);
+  Serial.println(s, 7);
+  
+  delay(100);
+  start = micros();
+  s = c.second();
+  stop = micros();
+  Serial.println(stop - start);
+  Serial.println(s, 7);
+  
+  delay(100);
+  start = micros();
+  s = c.tenthousand();
+  stop = micros();
+  Serial.println(stop - start);
+  Serial.println(s, 7);
+
+  Serial.println();
+}
+
+
+void testCompare()
+{
+  Serial.println(__FUNCTION__);
+
+  delay(100);
+  start = micros();
+  bool b = (a == a);
+  stop = micros();
+  Serial.println(stop - start);
+  Serial.println(b);
+
+
+  Serial.println();
+}
+
+
+void testNegate()
+{
+  Serial.println(__FUNCTION__);
+
+  delay(100);
+  start = micros();
+  a = -a;
+  stop = micros();
+  Serial.println(stop - start);
+  Serial.println(b);
+
+  Serial.println();
+}
+
+
+void testAdd()
+{
+  Serial.println(__FUNCTION__);
+
+  delay(100);
+  start = micros();
+  Angle d = a + b;
+  stop = micros();
+  Serial.println(stop - start);
+  Serial.println(d);
+
+  float rnd = random(36000) / 100.0 - 180;
+  delay(100);
+  start = micros();
+  d = a + rnd;
+  stop = micros();
+  Serial.println(stop - start);
+  Serial.println(d);
+
+  Serial.println();
+}
+
+
+void testMultiply()
+{
+  Serial.println(__FUNCTION__);
+
+  a = 5.25;
+  delay(100);
+  start = micros();
+  a = a * 5.5;
+  stop = micros();
+  Serial.println(stop - start);
+  Serial.println(a);
+
+  float rnd = random(36000) / 100.0 - 180;
+  delay(100);
+  start = micros();
+  a = a * rnd;
+  stop = micros();
+  Serial.println(stop - start);
+  Serial.println(a);
+
+  Serial.println();
+}
+
+
+
+
+void testDivide()
+{
+  Serial.println(__FUNCTION__);
+
+  a = 5.25;
+  delay(100);
+  start = micros();
+  a = a / 5.5;
+  stop = micros();
+  Serial.println(stop - start);
+  Serial.println(a);
+
+  float rnd = random(36000) / 100.0 - 180;
+  delay(100);
+  start = micros();
+  a = a / rnd;
+  stop = micros();
+  Serial.println(stop - start);
+  Serial.println(a);
+
+  Serial.println();
+}
+
+
+void testRatio()
+{
+  Serial.println(__FUNCTION__);
+
+  a = 7.50;
+  b = 57.456789;
+  delay(100);
+  start = micros();
+  float s = a / b;
+  stop = micros();
+  Serial.println(stop - start);
+  Serial.println(s);
+
+  Serial.println();
+}
+
+
+void setup()
+{
+  Serial.begin(115200);
+  Serial.println(__FILE__);
+  Serial.print("ANGLE_LIB_VERSION: ");
+  Serial.println(ANGLE_LIB_VERSION);
+
+  testConstructors();
+  testToDouble();
+  testParts();
+  testNegate();
+  testCompare();
+  testAdd();
+  testMultiply();
+  testDivide();
+  testRatio();
+
+  Serial.println("\nDone...");
+}
+
+
+void loop()
+{
+}
+
+
+//  -- END OF FILE --
diff --git a/examples/Angle_performance/performance_0.1.14.txt b/examples/Angle_performance/performance_0.1.14.txt
new file mode 100644
index 0000000..48b8c06
--- /dev/null
+++ b/examples/Angle_performance/performance_0.1.14.txt
@@ -0,0 +1,63 @@
+Arduino UNO
+IDE 1.8.19
+
+Angle_performance.ino
+ANGLE_LIB_VERSION: 0.1.14
+testConstructors
+212
+-45.59'15"5555
+220
+-45.59'15"5555
+
+testToDouble
+40
+1.0341668
+40
+-1.0341678
+164
+360.00'00"0000
+
+testParts
+4
+1.0000000
+8
+2.0000000
+8
+3.0000000
+8
+4.0000000
+8
+5.0000000
+
+testNegate
+12
+45.30'00"0000
+
+testCompare
+4
+1
+
+testAdd
+52
+44.27'56"9996
+272
+-12.57'50"9740
+
+testMultiply
+216
+28.52'30"0000
+300
+360.38'56"0230
+
+testDivide
+236
+0.57'16"3636
+312
+0.01'24"3694
+
+testRatio
+96
+0.13
+
+
+Done...
diff --git a/library.json b/library.json
index 77fb759..e220d49 100644
--- a/library.json
+++ b/library.json
@@ -20,7 +20,7 @@
     "type": "git",
     "url": "https://github.com/RobTillaart/Angle.git"
   },
-  "version": "0.1.13",
+  "version": "0.1.14",
   "license": "MIT",
   "frameworks": "arduino",
   "platforms": "*",
diff --git a/library.properties b/library.properties
index a633ca9..b94e9ea 100644
--- a/library.properties
+++ b/library.properties
@@ -1,5 +1,5 @@
 name=Angle
-version=0.1.13
+version=0.1.14
 author=Rob Tillaart <rob.tillaart@gmail.com>
 maintainer=Rob Tillaart <rob.tillaart@gmail.com>
 sentence=Library to convert between floating point angle to minutes hours representation.
diff --git a/test/unit_test_001.cpp b/test/unit_test_001.cpp
index 961cd19..dbd0072 100644
--- a/test/unit_test_001.cpp
+++ b/test/unit_test_001.cpp
@@ -42,6 +42,7 @@ unittest_setup()
   fprintf(stderr, "ANGLE_LIB_VERSION: %s\n", (char *) ANGLE_LIB_VERSION);
 }
 
+
 unittest_teardown()
 {
 }
@@ -131,7 +132,7 @@ unittest(test_Radians)
 }
 
 
-// mainly tests if operators still work, not a quality test (yet)
+//  mainly tests if operators still work, not a quality test (yet)
 unittest(test_math)
 {
   Angle a(1, 2, 3, 4);
@@ -182,4 +183,6 @@ unittest(test_compare)
 
 unittest_main()
 
-// --------
+
+//  -- END OF FILE --
+