Add ability to set padding byte for isotp frames

"isotp.setPaddingByte(0x??);"
collin80 · Dec 12, 2023 · f3ea2c6 · f3ea2c6
1 parent 466e0c0
commit f3ea2c6
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Showing 4 changed files with 18 additions and 3 deletions.
diff --git a/bus_protocols/isotp_handler.cpp b/bus_protocols/isotp_handler.cpp
@@ -10,6 +10,7 @@ ISOTP_HANDLER::ISOTP_HANDLER()
     sendPartialMessages = false;
     lastSenderBus = 0;
     lastSenderID = 0;
+    padByte = (char)0xAA;
 
     modelFrames = MainWindow::getReference()->getCANFrameModel()->getListReference();
 
@@ -21,6 +22,11 @@ ISOTP_HANDLER::~ISOTP_HANDLER()
     disconnect(&frameTimer, SIGNAL(timeout()), this, SLOT(frameTimerTick()));
 }
 
+void ISOTP_HANDLER::setPadByte(char newpad)
+{
+    padByte = newpad;
+}
+
 void ISOTP_HANDLER::setExtendedAddressing(bool mode)
 {
     useExtendedAddressing = mode;
@@ -67,7 +73,7 @@ void ISOTP_HANDLER::sendISOTPFrame(int bus, int ID, QByteArray data)
 
     if (data.length() < 8)
     {
-        QByteArray bytes(8,0);
+        QByteArray bytes(8, padByte);
         bytes.resize(8);
         bytes[0] = data.length();
         for (int i = 0; i < data.length(); i++) bytes[i + 1] = data[i];
@@ -76,7 +82,7 @@ void ISOTP_HANDLER::sendISOTPFrame(int bus, int ID, QByteArray data)
     }
     else //need to send a multi-part ISO_TP message - Respects timing and frame number based flow control
     {
-        QByteArray bytes(8, 0);
+        QByteArray bytes(8, padByte);
         bytes[0] = 0x10 + (data.length() / 256);
         bytes[1] = data.length() & 0xFF;
         for (int i = 0; i < 6; i++) bytes[2 + i] = data[currByte++];
@@ -89,7 +95,7 @@ void ISOTP_HANDLER::sendISOTPFrame(int bus, int ID, QByteArray data)
         frameTimer.start();
         while (currByte < data.length())
         {
-            for (int b = 0; b < 8; b++) bytes[b] = 0x00;
+            for (int b = 0; b < 8; b++) bytes[b] = padByte;
             bytes[0] = 0x20 + sequence; //Consecutive Frame starts from 0x20 + 1 (2: Frame type, 1: Sequence number)
             sequence = (sequence + 1) & 0xF;
             int bytesToGo = data.length() - currByte;

diff --git a/bus_protocols/isotp_handler.h b/bus_protocols/isotp_handler.h
@@ -26,6 +26,7 @@ class ISOTP_HANDLER : public QObject
     void addFilter(int pBusId, uint32_t ID, uint32_t mask);
     void removeFilter(int pBusId, uint32_t ID, uint32_t mask);
     void clearAllFilters();
+    void setPadByte(char newpad);
 
 public slots:
     void updatedFrames(int);
@@ -50,6 +51,7 @@ public slots:
     QTimer frameTimer;
     uint32_t lastSenderID;
     uint32_t lastSenderBus;
+    char padByte;
 
     void processFrame(const CANFrame &frame);
     void checkNeedFlush(uint64_t ID);

diff --git a/scriptcontainer.cpp b/scriptcontainer.cpp
@@ -329,6 +329,12 @@ void ISOTPScriptHelper::sendISOTP(QJSValue bus, QJSValue id, QJSValue length, QJ
     handler->sendISOTPFrame(msg.bus, msg.frameId(), msg.payload());
 }
 
+void ISOTPScriptHelper::setPaddingByte(QJSValue byt)
+{
+    char newB = byt.toInt();
+    handler->setPadByte(newB);
+}
+
 void ISOTPScriptHelper::setRxCallback(QJSValue cb)
 {
     gotFrameFunction = cb;

diff --git a/scriptcontainer.h b/scriptcontainer.h
@@ -45,6 +45,7 @@ public slots:
     void clearFilters();
     void sendISOTP(QJSValue bus, QJSValue id, QJSValue length, QJSValue data);
     void setRxCallback(QJSValue cb);
+    void setPaddingByte(QJSValue byt);
 private slots:
     void newISOMessage(ISOTP_MESSAGE msg);
 private: