diff --git a/Readme.md b/Readme.md
index a9a305f..d3fae7f 100644
--- a/Readme.md
+++ b/Readme.md
@@ -43,6 +43,10 @@ What is included
 
 For the details of the mapped PGNs and NMEA sentences refer to [Conversions](doc/Conversions.pdf).
 
+License
+-------
+This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either [version 2 of the License](LICENSE), or (at your option) any later version.
+
 Hardware
 --------
 The software is prepared to run on different kinds of ESP32 based modules and accessoirs. For some of them prebuild binaries are available that only need to be flashed, others would require to add some definitions of the used PINs and features and to build the binary.
diff --git a/lib/config/GwConverterConfig.h b/lib/config/GwConverterConfig.h
index 4a93a71..25ca39e 100644
--- a/lib/config/GwConverterConfig.h
+++ b/lib/config/GwConverterConfig.h
@@ -3,7 +3,7 @@
   This code is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation; either
-  version 2.1 of the License, or (at your option) any later version.
+  version 2 of the License, or (at your option) any later version.
   This code is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
diff --git a/lib/hardware/GwChannelModes.h b/lib/hardware/GwChannelModes.h
index a9d7757..e6c42de 100644
--- a/lib/hardware/GwChannelModes.h
+++ b/lib/hardware/GwChannelModes.h
@@ -2,7 +2,7 @@
   This code is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation; either
-  version 2.1 of the License, or (at your option) any later version.
+  version 2 of the License, or (at your option) any later version.
   This code is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
diff --git a/lib/hardware/GwHardware.h b/lib/hardware/GwHardware.h
index 41bca41..10a7404 100644
--- a/lib/hardware/GwHardware.h
+++ b/lib/hardware/GwHardware.h
@@ -2,7 +2,7 @@
   This code is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation; either
-  version 2.1 of the License, or (at your option) any later version.
+  version 2 of the License, or (at your option) any later version.
   This code is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
diff --git a/lib/hardware/GwM5Base.h b/lib/hardware/GwM5Base.h
index 2e88f51..67c865e 100644
--- a/lib/hardware/GwM5Base.h
+++ b/lib/hardware/GwM5Base.h
@@ -2,7 +2,7 @@
   This code is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation; either
-  version 2.1 of the License, or (at your option) any later version.
+  version 2 of the License, or (at your option) any later version.
   This code is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
diff --git a/lib/hardware/GwM5Grove.h b/lib/hardware/GwM5Grove.h
index 220ee01..44761a1 100644
--- a/lib/hardware/GwM5Grove.h
+++ b/lib/hardware/GwM5Grove.h
@@ -2,7 +2,7 @@
   This code is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation; either
-  version 2.1 of the License, or (at your option) any later version.
+  version 2 of the License, or (at your option) any later version.
   This code is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
diff --git a/lib/hardware/GwM5Grove.in b/lib/hardware/GwM5Grove.in
index 9858783..c98d4d1 100644
--- a/lib/hardware/GwM5Grove.in
+++ b/lib/hardware/GwM5Grove.in
@@ -2,7 +2,7 @@
   This code is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation; either
-  version 2.1 of the License, or (at your option) any later version.
+  version 2 of the License, or (at your option) any later version.
   This code is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
diff --git a/lib/nmea0183ton2k/NMEA0183AIStoNMEA2000.h b/lib/nmea0183ton2k/NMEA0183AIStoNMEA2000.h
index 169f181..a627952 100644
--- a/lib/nmea0183ton2k/NMEA0183AIStoNMEA2000.h
+++ b/lib/nmea0183ton2k/NMEA0183AIStoNMEA2000.h
@@ -2,7 +2,7 @@
   This code is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation; either
-  version 2.1 of the License, or (at your option) any later version.
+  version 2 of the License, or (at your option) any later version.
   This code is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
diff --git a/lib/sensors/GwSensor.cpp b/lib/sensors/GwSensor.cpp
index d0d580b..abdb508 100644
--- a/lib/sensors/GwSensor.cpp
+++ b/lib/sensors/GwSensor.cpp
@@ -3,7 +3,7 @@
   This code is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation; either
-  version 2.1 of the License, or (at your option) any later version.
+  version 2 of the License, or (at your option) any later version.
   This code is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
diff --git a/lib/sensors/GwSensor.h b/lib/sensors/GwSensor.h
index 3077360..48eb5b2 100644
--- a/lib/sensors/GwSensor.h
+++ b/lib/sensors/GwSensor.h
@@ -3,7 +3,7 @@
   This code is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation; either
-  version 2.1 of the License, or (at your option) any later version.
+  version 2 of the License, or (at your option) any later version.
   This code is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
diff --git a/lib/spitask/GWDMS22B.cpp b/lib/spitask/GWDMS22B.cpp
index fca345e..0447fb2 100644
--- a/lib/spitask/GWDMS22B.cpp
+++ b/lib/spitask/GWDMS22B.cpp
@@ -3,7 +3,7 @@
   This code is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation; either
-  version 2.1 of the License, or (at your option) any later version.
+  version 2 of the License, or (at your option) any later version.
   This code is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
diff --git a/lib/spitask/GWDMS22B.h b/lib/spitask/GWDMS22B.h
index de53804..29a0b1b 100644
--- a/lib/spitask/GWDMS22B.h
+++ b/lib/spitask/GWDMS22B.h
@@ -3,7 +3,7 @@
   This code is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation; either
-  version 2.1 of the License, or (at your option) any later version.
+  version 2 of the License, or (at your option) any later version.
   This code is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
diff --git a/lib/spitask/GwSpiSensor.h b/lib/spitask/GwSpiSensor.h
index c12a410..ec21afe 100644
--- a/lib/spitask/GwSpiSensor.h
+++ b/lib/spitask/GwSpiSensor.h
@@ -3,7 +3,7 @@
   This code is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation; either
-  version 2.1 of the License, or (at your option) any later version.
+  version 2 of the License, or (at your option) any later version.
   This code is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
diff --git a/lib/spitask/GwSpiTask.cpp b/lib/spitask/GwSpiTask.cpp
index a5dda8a..54f9f3d 100644
--- a/lib/spitask/GwSpiTask.cpp
+++ b/lib/spitask/GwSpiTask.cpp
@@ -3,7 +3,7 @@
   This code is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation; either
-  version 2.1 of the License, or (at your option) any later version.
+  version 2 of the License, or (at your option) any later version.
   This code is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
diff --git a/lib/spitask/GwSpiTask.h b/lib/spitask/GwSpiTask.h
index 0714a31..b42b462 100644
--- a/lib/spitask/GwSpiTask.h
+++ b/lib/spitask/GwSpiTask.h
@@ -3,7 +3,7 @@
   This code is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation; either
-  version 2.1 of the License, or (at your option) any later version.
+  version 2 of the License, or (at your option) any later version.
   This code is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
diff --git a/src/main.cpp b/src/main.cpp
index 6daaa51..de56930 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -3,7 +3,7 @@
   This code is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation; either
-  version 2.1 of the License, or (at your option) any later version.
+  version 2 of the License, or (at your option) any later version.
   This code is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU