RobTillaart · RobTillaart · Jan 15, 2026 · Jan 15, 2026
diff --git a/.github/workflows/arduino-lint.yml b/.github/workflows/arduino-lint.yml
@@ -6,8 +6,8 @@ jobs:
     runs-on: ubuntu-latest
     timeout-minutes: 5
     steps:
-      - uses: actions/checkout@v4
-      - uses: arduino/arduino-lint-action@v1
+      - uses: actions/checkout@v6
+      - uses: arduino/arduino-lint-action@v2
         with:
           library-manager: update
           compliance: strict
diff --git a/.github/workflows/arduino_test_runner.yml b/.github/workflows/arduino_test_runner.yml
@@ -6,9 +6,8 @@ jobs:
   runTest:
     runs-on: ubuntu-latest
     timeout-minutes: 20
-
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
       - uses: ruby/setup-ruby@v1
         with:
           ruby-version: 2.6

diff --git a/.github/workflows/jsoncheck.yml b/.github/workflows/jsoncheck.yml
@@ -5,13 +5,15 @@ on:
     paths:
       - '**.json'
   pull_request:
+    paths:
+      - '**.json'
 
 jobs:
   test:
     runs-on: ubuntu-latest
     timeout-minutes: 5
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
       - name: json-syntax-check
         uses: limitusus/json-syntax-check@v2
         with:

diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -6,14 +6,17 @@ The format is based on [Keep a Changelog](http://keepachangelog.com/)
 and this project adheres to [Semantic Versioning](http://semver.org/).
 
 
-## [0.3.3] - 2025-03-23
+## [0.3.5] - 2026-01-15
+- update GitHub actions
+- minor edits
+
+## [0.3.4] - 2025-03-23
 - fix #28, prevent promotion of constants to double. Kudos to Harrison3000
 - replace M_PI by a const float _PI_ to prevent promotion.
 - update examples
 - update readme.md (minor)
 - minor edits
 
-
 ## [0.3.3] - 2023-11-02
 - update readme.md
 - update keywords.txt
@@ -102,17 +105,15 @@ is added, as it uses the same **isintable16\[\]** interpolation table.
 
 There is no **atan()** or **atan2()** replacement.
 
-
 ## [0.1.4] - 2020-09-08
 - rewrite itan()
-- cleanup
+- clean up
 - examples
 
 The library (0.1.4) provides an **itan()** which improved accuracy
 upon the (0.1.3) version and performance for the ESP32.
 Performance on AVR (UNO) is still an issue, accuracy is OK.
 
-
 ## [0.1.3] - 2020-09-07
 - initial release.
 

diff --git a/FastTrig.cpp b/FastTrig.cpp
@@ -1,7 +1,7 @@
 //
 //    FILE: FastTrig.cpp
 //  AUTHOR: Rob Tillaart
-// VERSION: 0.3.4
+// VERSION: 0.3.5
 // PURPOSE: Arduino library for a faster approximation of sin() and cos()
 //    DATE: 2011-08-18
 //     URL: https://github.com/RobTillaart/FastTrig

diff --git a/FastTrig.h b/FastTrig.h
@@ -2,7 +2,7 @@
 //
 //    FILE: FastTrig.h
 //  AUTHOR: Rob Tillaart
-// VERSION: 0.3.4
+// VERSION: 0.3.5
 // PURPOSE: Arduino library for a faster approximation of sin() and cos()
 //    DATE: 2011-08-18
 //     URL: https://github.com/RobTillaart/FastTrig
@@ -18,7 +18,7 @@
 #endif
 
 
-#define FAST_TRIG_LIB_VERSION             (F("0.3.4"))
+#define FAST_TRIG_LIB_VERSION             (F("0.3.5"))
 
 
 #ifdef __cplusplus

diff --git a/LICENSE b/LICENSE
@@ -1,6 +1,6 @@
 MIT License
 
-Copyright (c) 2011-2025 Rob Tillaart
+Copyright (c) 2011-2026 Rob Tillaart
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal

diff --git a/README.md b/README.md
@@ -46,10 +46,14 @@ between **isin(int(x))** and **isin(int(x+1))**.
 Of course this introduces an error but the error is small and performance is still 
 quite fast (which was the goal).
 
+Feedback as always is welcome.
+
 
 ### Related
 
+- https://github.com/RobTillaart/fastTrig
 - https://github.com/RobTillaart/fast_math
+- https://github.com/RobTillaart/printHelpers a.o. print floats in scientific notation
 - https://github.com/RobTillaart?tab=repositories&q=math
 
 

diff --git a/examples/fastTrig_atan_performance/fastTrig_atan_performance.ino b/examples/fastTrig_atan_performance/fastTrig_atan_performance.ino
@@ -1,6 +1,5 @@
 //    FILE: fastTrig_atan_performance.ino
 //  AUTHOR: Rob Tillaart
-//    DATE: 2022-12-05
 // PURPOSE: performance and accuracy measurement
 //     URL: https://github.com/RobTillaart/FastTrig
 

diff --git a/examples/fastTrig_generate_tables/fastTrig_generate_tables.ino b/examples/fastTrig_generate_tables/fastTrig_generate_tables.ino
@@ -3,7 +3,6 @@
 //  AUTHOR: Rob Tillaart
 // PURPOSE: generate look up tables for goniometry functions (and others)
 //          these are not optimized for interpolation.
-//    DATE: 2020-09-08
 //     URL: https://github.com/RobTillaart/FastTrig
 
 //  TODO
@@ -20,7 +19,7 @@ void setup()
   while (!Serial);
   Serial.println();
   Serial.println(__FILE__);
-  Serial.println("FAST_TRIG_LIB_VERSION: ");
+  Serial.print("FAST_TRIG_LIB_VERSION: ");
   Serial.println(FAST_TRIG_LIB_VERSION);
   Serial.println();
 

diff --git a/examples/fastTrig_hypot_accuracy/fastTrig_hypot_accuracy.ino b/examples/fastTrig_hypot_accuracy/fastTrig_hypot_accuracy.ino
@@ -1,6 +1,5 @@
 //    FILE: fastTrig_hypot_accuracy.ino
 //  AUTHOR: Rob Tillaart
-//    DATE: 2022-12-05
 // PURPOSE: performance and accuracy measurement
 //     URL: https://github.com/RobTillaart/FastTrig
 
@@ -20,7 +19,7 @@ void setup()
   while (!Serial);
   Serial.println();
   Serial.println(__FILE__);
-  Serial.println("FAST_TRIG_LIB_VERSION: ");
+  Serial.print("FAST_TRIG_LIB_VERSION: ");
   Serial.println(FAST_TRIG_LIB_VERSION);
   Serial.println();
   delay(10);

diff --git a/examples/fastTrig_hypot_performance/fastTrig_hypot_performance.ino b/examples/fastTrig_hypot_performance/fastTrig_hypot_performance.ino
@@ -1,6 +1,5 @@
 //    FILE: fastTrig_hypot_performance.ino
 //  AUTHOR: Rob Tillaart
-//    DATE: 2022-12-05
 // PURPOSE: performance and accuracy measurement
 //     URL: https://github.com/RobTillaart/FastTrig
 
@@ -20,7 +19,7 @@ void setup()
   while (!Serial);
   Serial.println();
   Serial.println(__FILE__);
-  Serial.println("FAST_TRIG_LIB_VERSION: ");
+  Serial.print("FAST_TRIG_LIB_VERSION: ");
   Serial.println(FAST_TRIG_LIB_VERSION);
   Serial.println();
   delay(10);

diff --git a/examples/fastTrig_isincos/fastTrig_isincos.ino b/examples/fastTrig_isincos/fastTrig_isincos.ino
@@ -1,6 +1,5 @@
 //    FILE: isincos.ino
 //  AUTHOR: Rob Tillaart
-//    DATE: 2022-12-09
 // PURPOSE: R&D
 //     URL: https://github.com/RobTillaart/FastTrig
 
@@ -20,7 +19,7 @@ void setup()
   while (!Serial);
   Serial.println();
   Serial.println(__FILE__);
-  Serial.println("FAST_TRIG_LIB_VERSION: ");
+  Serial.print("FAST_TRIG_LIB_VERSION: ");
   Serial.println(FAST_TRIG_LIB_VERSION);
   Serial.println();
   delay(10);

diff --git a/examples/fastTrig_isincos256/fastTrig_isincos256.ino b/examples/fastTrig_isincos256/fastTrig_isincos256.ino
@@ -1,6 +1,5 @@
 //    FILE: fastTrig_isincos256.ino
 //  AUTHOR: Rob Tillaart
-//    DATE: 2022-12-09
 // PURPOSE: R&D
 //     URL: https://github.com/RobTillaart/FastTrig
 
@@ -20,7 +19,7 @@ void setup()
   while (!Serial);
   Serial.println();
   Serial.println(__FILE__);
-  Serial.println("FAST_TRIG_LIB_VERSION: ");
+  Serial.print("FAST_TRIG_LIB_VERSION: ");
   Serial.println(FAST_TRIG_LIB_VERSION);
   Serial.println();
   delay(10);

diff --git a/examples/fastTrig_optimize/fastTrig_optimize.ino b/examples/fastTrig_optimize/fastTrig_optimize.ino
@@ -2,7 +2,6 @@
 //    FILE: fastTrig_optimize.ino
 //  AUTHOR: Rob Tillaart
 // PURPOSE: sketch to optimize the table for interpolation
-//    DATE: 2020-09-06
 //     URL: https://github.com/RobTillaart/FastTrig
 
 //  WARNING TAKES A LOT OF TIME ON 16 MHz
@@ -29,7 +28,7 @@ void setup()
   while (!Serial);
   Serial.println();
   Serial.println(__FILE__);
-  Serial.println("FAST_TRIG_LIB_VERSION: ");
+  Serial.print("FAST_TRIG_LIB_VERSION: ");
   Serial.println(FAST_TRIG_LIB_VERSION);
   Serial.println();
 

diff --git a/examples/fastTrig_playground/fastTrig_playground.ino b/examples/fastTrig_playground/fastTrig_playground.ino
@@ -2,7 +2,6 @@
 //    FILE: fastTrig_playground.ino
 //  AUTHOR: Rob Tillaart
 // PURPOSE: playground to play with tables.
-//    DATE: 2020-09-08
 //     URL: https://github.com/RobTillaart/FastTrig
 
 //  NOTES
@@ -80,6 +79,7 @@ void setup()
   while (!Serial);
   Serial.println();
   Serial.println(__FILE__);
+  Serial.println("FastTrig");
   Serial.println();
 
   test_accuracy();

diff --git a/examples/fastTrig_plot/fastTrig_plot.ino b/examples/fastTrig_plot/fastTrig_plot.ino
@@ -2,7 +2,6 @@
 //    FILE: fastTrig_plot.ino
 //  AUTHOR: Rob Tillaart
 // PURPOSE: testing the fastTrigonio functions
-//    DATE: 2020-09-07
 //     URL: https://github.com/RobTillaart/FastTrig
 
 //  sketch to visually compare tan(x) and itan(x)
@@ -22,7 +21,7 @@ void setup()
   while (!Serial);
   Serial.println();
   Serial.println(__FILE__);
-  Serial.println("FAST_TRIG_LIB_VERSION: ");
+  Serial.print("FAST_TRIG_LIB_VERSION: ");
   Serial.println(FAST_TRIG_LIB_VERSION);
   Serial.println();
 

diff --git a/examples/fastTrig_test1/fastTrig_test1.ino b/examples/fastTrig_test1/fastTrig_test1.ino
@@ -2,8 +2,6 @@
 //    FILE: fastTrig_test1.ino
 //  AUTHOR: Rob Tillaart
 // PURPOSE: testing the fastTrigonio functions
-//    DATE: 2020-08-30
-//    (c) : MIT
 //     URL: https://github.com/RobTillaart/FastTrig
 
 
@@ -21,7 +19,7 @@ void setup()
   while (!Serial);
   Serial.println();
   Serial.println(__FILE__);
-  Serial.println("FAST_TRIG_LIB_VERSION: ");
+  Serial.print("FAST_TRIG_LIB_VERSION: ");
   Serial.println(FAST_TRIG_LIB_VERSION);
   Serial.println();
 

diff --git a/examples/fastTrig_test2/fastTrig_test2.ino b/examples/fastTrig_test2/fastTrig_test2.ino
@@ -2,8 +2,6 @@
 //    FILE: fastTrig_test2.ino
 //  AUTHOR: Rob Tillaart
 // PURPOSE: testing the itan functions
-//    DATE: 2021-08-10
-//    (c) : MIT
 //     URL: https://github.com/RobTillaart/FastTrig
 
 
@@ -21,7 +19,7 @@ void setup()
   while (!Serial);
   Serial.println();
   Serial.println(__FILE__);
-  Serial.println("FAST_TRIG_LIB_VERSION: ");
+  Serial.print("FAST_TRIG_LIB_VERSION: ");
   Serial.println(FAST_TRIG_LIB_VERSION);
   Serial.println();
 

diff --git a/examples/fastTrig_test_arc/fastTrig_test_arc.ino b/examples/fastTrig_test_arc/fastTrig_test_arc.ino
@@ -3,7 +3,6 @@
 //  AUTHOR: Rob Tillaart
 // VERSION: 0.1.1
 // PURPOSE: testing the fastTrigonio functions
-//    DATE: 2020-09-09
 //     URL: https://github.com/RobTillaart/FastTrig
 
 
@@ -22,7 +21,7 @@ void setup()
   while (!Serial);
   Serial.println();
   Serial.println(__FILE__);
-  Serial.println("FAST_TRIG_LIB_VERSION: ");
+  Serial.print("FAST_TRIG_LIB_VERSION: ");
   Serial.println(FAST_TRIG_LIB_VERSION);
   Serial.println();
 

diff --git a/library.json b/library.json
@@ -15,7 +15,7 @@
     "type": "git",
     "url": "https://github.com/RobTillaart/FastTrig"
   },
-  "version": "0.3.4",
+  "version": "0.3.5",
   "license": "MIT",
   "frameworks": "*",
   "platforms": "*",

diff --git a/library.properties b/library.properties
@@ -1,5 +1,5 @@
 name=FastTrig
-version=0.3.4
+version=0.3.5
 author=Rob Tillaart <rob.tillaart@gmail.com>
 maintainer=Rob Tillaart <rob.tillaart@gmail.com>
 sentence=Arduino library with interpolated lookup for sin(), cos(), tan(), atan2() and more.