diff --git a/.gitignore b/.gitignore
index b0b8666..61eedc4 100644
--- a/.gitignore
+++ b/.gitignore
@@ -10,6 +10,7 @@ config.h
 .vscode/extensions.json
 mySetup.h
 mySetup.cpp
+myHal.cpp
 myAutomation.h
 myFilter.cpp
 myAutomation.h
diff --git a/IODevice.cpp b/IODevice.cpp
index c7ab7c0..63a6d8b 100644
--- a/IODevice.cpp
+++ b/IODevice.cpp
@@ -28,8 +28,9 @@
 #define USE_FAST_IO
 #endif
 
-// Link to mySetup function.  If not defined, the function reference will be NULL.
-extern __attribute__((weak)) void mySetup();
+// Link to halSetup function.  If not defined, the function reference will be NULL.
+extern __attribute__((weak)) void halSetup();
+extern __attribute__((weak)) void mySetup();  // Deprecated function name, output warning if it's declared
 
 //==================================================================================================================
 // Static methods
@@ -61,12 +62,15 @@ void IODevice::begin() {
   }
   _initPhase = false;
 
-  // Call user's mySetup() function (if defined in the build in mySetup.cpp).
+  // Check for presence of deprecated mySetup() function, and output warning.
+  if (mySetup)
+    DIAG(F("WARNING: mySetup() function should be renamed to halSetup()"));
+
+  // Call user's halSetup() function (if defined in the build in myHal.cpp).
   //  The contents will depend on the user's system hardware configuration.
-  //  The mySetup.cpp file is a standard C++ module so has access to all of the DCC++EX APIs.
-  if (mySetup) {
-    mySetup();
-  }
+  //  The myHal.cpp file is a standard C++ module so has access to all of the DCC++EX APIs.
+  if (halSetup)
+    halSetup();
 }
 
 // Overarching static loop() method for the IODevice subsystem.  Works through the
diff --git a/mySetup.cpp_example.txt b/myHal.cpp_example.txt
similarity index 97%
rename from mySetup.cpp_example.txt
rename to myHal.cpp_example.txt
index e93ac53..6ea5c00 100644
--- a/mySetup.cpp_example.txt
+++ b/myHal.cpp_example.txt
@@ -1,10 +1,10 @@
-//  Sample mySetup.cpp file.
+//  Sample myHal.cpp file.
 //
-// To use this file, copy it to mySetup.cpp and uncomment the directives and/or
+// To use this file, copy it to myHal.cpp and uncomment the directives and/or
 // edit them to satisfy your requirements.  
 
 // Note that if the file has a .cpp extension it WILL be compiled into the build
-// and the mySetup() function WILL be invoked.
+// and the halSetup() function WILL be invoked.
 //
 // To prevent this, temporarily rename it to mySetup.txt or similar.
 //
@@ -128,7 +128,7 @@
 // referenced by commands in mySetup.h.
 //=======================================================================
 
-void mySetup() {
+void halSetup() {
 
   // Alternative way of creating a module driver, which has to be within the mySetup() function
   // The other devices can also be created in this way.  The parameter lists for the