From d1060785fb4cd9054e9f76602c091940cf8d40f4 Mon Sep 17 00:00:00 2001
From: bernatalbet <30940179+bernatalbet@users.noreply.github.com>
Date: Sat, 13 Apr 2024 18:36:42 +0200
Subject: [PATCH 1/3] Update ModbusMaster.cpp

I created a class which inherits and extends the current functionality, so that now I can do this:

    void preTransmission() override {
        digitalWrite(mEnablePin, HIGH); // Enable Modbus communication
    }
    void postTransmission() override {
        digitalWrite(mEnablePin, LOW); // Disable Modbus communication
    }

Where "mEnablePin" is passed as part of the constructor.

In the current implementation, I tried to implement a solution to use different Enable pins in different instantiated objects, but then I must set static functions externally to the class, so I can't encapsulate the functionality to my inherited class.
---
 src/ModbusMaster.cpp | 33 +++++++++++++++++++++++++--------
 1 file changed, 25 insertions(+), 8 deletions(-)

diff --git a/src/ModbusMaster.cpp b/src/ModbusMaster.cpp
index 4169e58..ee9f13d 100644
--- a/src/ModbusMaster.cpp
+++ b/src/ModbusMaster.cpp
@@ -216,6 +216,29 @@ void ModbusMaster::postTransmission(void (*postTransmission)())
   _postTransmission = postTransmission;
 }
 
+/**
+Function extends the preTransmission functionality, and we can now
+inherit the class and override this method.
+
+@see ModbusMaster::ModbusMasterTransaction()
+@see ModbusMaster::preTransmission()
+*/
+void ModbusMaster::preTransmission() {
+	if (_preTransmission)
+		_preTransmission();
+}
+
+/**
+Function extends the preTransmission functionality, and we can now
+inherit the class and override this method.
+
+@see ModbusMaster::ModbusMasterTransaction()
+@see ModbusMaster::preTransmission()
+*/
+void ModbusMaster::postTransmission() {
+	if (_postTransmission)
+		_postTransmission();
+}
 
 /**
 Retrieve data from response buffer.
@@ -705,10 +728,7 @@ uint8_t ModbusMaster::ModbusMasterTransaction(uint8_t u8MBFunction)
   while (_serial->read() != -1);
 
   // transmit request
-  if (_preTransmission)
-  {
-    _preTransmission();
-  }
+  preTransmission();
   for (i = 0; i < u8ModbusADUSize; i++)
   {
     _serial->write(u8ModbusADU[i]);
@@ -716,10 +736,7 @@ uint8_t ModbusMaster::ModbusMasterTransaction(uint8_t u8MBFunction)
   
   u8ModbusADUSize = 0;
   _serial->flush();    // flush transmit buffer
-  if (_postTransmission)
-  {
-    _postTransmission();
-  }
+  postTransmission();
   
   // loop until we run out of time or bytes, or an error occurs
   u32StartTime = millis();

From 68e531907cc4593aed7df65b464c7ba038da5f41 Mon Sep 17 00:00:00 2001
From: bernatalbet <30940179+bernatalbet@users.noreply.github.com>
Date: Sat, 13 Apr 2024 18:43:16 +0200
Subject: [PATCH 2/3] Small fix in the comment

---
 src/ModbusMaster.cpp | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/ModbusMaster.cpp b/src/ModbusMaster.cpp
index ee9f13d..0558353 100644
--- a/src/ModbusMaster.cpp
+++ b/src/ModbusMaster.cpp
@@ -229,11 +229,11 @@ void ModbusMaster::preTransmission() {
 }
 
 /**
-Function extends the preTransmission functionality, and we can now
+Function extends the postTransmission functionality, and we can now
 inherit the class and override this method.
 
 @see ModbusMaster::ModbusMasterTransaction()
-@see ModbusMaster::preTransmission()
+@see ModbusMaster::postTransmission()
 */
 void ModbusMaster::postTransmission() {
 	if (_postTransmission)

From 6f810ac5d7214142500d861ecc2cb44632f7b2ba Mon Sep 17 00:00:00 2001
From: bernatalbet <30940179+bernatalbet@users.noreply.github.com>
Date: Sat, 13 Apr 2024 18:45:05 +0200
Subject: [PATCH 3/3] Virtual functions added to the .h file

---
 src/ModbusMaster.h | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/src/ModbusMaster.h b/src/ModbusMaster.h
index 8c433e6..0d50e4a 100644
--- a/src/ModbusMaster.h
+++ b/src/ModbusMaster.h
@@ -75,6 +75,8 @@ class ModbusMaster
     void idle(void (*)());
     void preTransmission(void (*)());
     void postTransmission(void (*)());
+    virtual void preTransmission();
+    virtual void postTransmission();
 
     // Modbus exception codes
     /**