configurable UART Pins

Author: mestrode

src/Lin_Interface.cpp

@@ -22,12 +22,9 @@ bool Lin_Interface::readFrame(uint8_t FrameID)
     uint8_t ProtectedID = getProtectedID(FrameID);
     bool ChecksumValid = false;
 
-    // start transmission
-    HardwareSerial::begin(baud, SERIAL_8N1);
-    writeBreak();                       // initiate Frame with a Break
-    HardwareSerial::write(0x55);        // Sync
-    HardwareSerial::write(ProtectedID); // PID
+    startTransmission(ProtectedID);
     HardwareSerial::flush();
+
     // wait for available data
     delay(100);
 
@@ -118,11 +115,8 @@ void Lin_Interface::writeFrame(uint8_t FrameID, uint8_t dataLen)
     uint8_t ProtectedID = getProtectedID(FrameID);
     uint8_t cksum = getChecksum(ProtectedID, dataLen);
 
-    // übertragung startet
-    HardwareSerial::begin(baud, SERIAL_8N1);
-    writeBreak();                       // initiate Frame with a Break
-    HardwareSerial::write(0x55);        // Sync
-    HardwareSerial::write(ProtectedID); // PID
+    startTransmission(ProtectedID);
+
     for (int i = 0; i < dataLen; ++i)
     {
         HardwareSerial::write(LinMessage[i]); // Message (array from 1..8)
@@ -210,10 +204,8 @@ void Lin_Interface::writeFrameClassic(uint8_t FrameID, uint8_t dataLen)
     uint8_t ProtectedID = getProtectedID(FrameID);
     uint8_t cksum = getChecksum(0x00, dataLen);
 
-    HardwareSerial::begin(baud, SERIAL_8N1);
-    writeBreak();                       // initiate Frame with a Break
-    HardwareSerial::write(0x55);        // Sync
-    HardwareSerial::write(ProtectedID); // ID
+    startTransmission(ProtectedID);
+
     for (int i = 0; i < dataLen; ++i)
     {
         HardwareSerial::write(LinMessage[i]); // Message (array from 1..8)
@@ -226,6 +218,22 @@ void Lin_Interface::writeFrameClassic(uint8_t FrameID, uint8_t dataLen)
     HardwareSerial::end();
 } // void Lin_Interface::writeFrameClassic
 
+/// Introduce Frame (Start UART, Break, Sync, PID)
+void Lin_Interface::startTransmission(uint8_t ProtectedID)
+{
+    // start UART
+    if (rxPin < 0 && txPin < 0) {
+        //no custom pins are defined
+        HardwareSerial::begin(baud, SERIAL_8N1);
+    } else {
+        HardwareSerial::begin(baud, SERIAL_8N1, rxPin, txPin);
+    }
+
+    writeBreak();                       // initiate Frame with a Break
+    HardwareSerial::write(0x55);        // Sync
+    HardwareSerial::write(ProtectedID); // PID
+} 
+
 /// Send a Break for introduction of a Frame
 /// This is done by sending a Byte (0x00) + Stop Bit by using half baud rate
 /// @returns if the 0x00 has been send

src/Lin_Interface.hpp

@@ -22,6 +22,8 @@ class Lin_Interface : private HardwareSerial
 
     int verboseMode = -1;
     unsigned long baud = 19200;
+    int8_t rxPin = -1;
+    int8_t txPin = -1;
 
     // 8 Data Bytes + ChkSum + some space for receiving complete frames
     uint8_t LinMessage[8 + 1 + 4] = {0};
@@ -33,6 +35,7 @@ class Lin_Interface : private HardwareSerial
 
 protected:
     uint32_t m_bitCycles;
+    void startTransmission(uint8_t ProtectedID);
     size_t writeBreak();
     uint8_t getProtectedID(uint8_t FrameID);
     uint8_t getChecksum(uint8_t ProtectedID, uint8_t datalen);