Did add some code for updating the RigState architecture. Not ready to swap it out yet, however.

Raduino/Raduino.ino

@@ -1475,6 +1475,13 @@ void checkAutoSaveFreqMode()
 
   rigState.vfo[0] = vfoA;
   rigState.vfo[1] = vfoB;
+  rigState.rit = ritRxFrequency - frequency;
+  rigState.flags = 0;
+  rigState.flags |= (vfoActive == VFO_B ? UBITX_VFOB_FLAG : 0);
+  rigState.flags |= (cwMode != 0 ? UBITX_CW_FLAG : 0);
+  rigState.flags |= (isUSB != 0 ? UBITX_USB_FLAG : 0);
+  rigState.flags |= (splitOn != 0 ? UBITX_SPLIT_FLAG : 0);
+  rigState.flags |= (ritOn != 0 ? UBITX_RIT_FLAG : 0);
 }
 
 void loop(){ 

Raduino/ubitx.h

@@ -341,6 +341,8 @@ extern void DisplayVersionInfo(const char* fwVersionInfo);
 extern int GetI2CSmeterValue(int valueType);  //ubitx_ui.ino
 
 extern void doRaduinoToTeensy(UBitxRigState* r);
+extern void updateStateFromRaduino(UBitxRigState& r);
+extern void updateRaduinoFromState(UBitxRigState& r);
 
 extern UBitxRigState rigState;
 

Raduino/ubitx_lcd_nextion.ino

@@ -997,23 +997,10 @@ UBitxRigState catState;
 void idle_process()
 {
   // KC4UPR 2021-02-05 added update process for Raduino-TeensyDSP coordination
-  // Note, need to not have to copy this every time...
-  if (vfoActive == VFO_A) {
-    rigState.vfo[0] = frequency;
-    rigState.flags &= ~UBITX_VFOB_FLAG;
-  } else if (vfoActive == VFO_B) {
-    rigState.vfo[1] = frequency;
-    rigState.flags |= UBITX_VFOB_FLAG;
-  }
+  updateStateFromRaduino(rigState);
   doRaduinoToTeensy(&rigState);
-  if (vfoActive == VFO_A) {
-    if (rigState.vfo[0] != frequency) {
-      setFrequency(rigState.vfo[0]);
-    } else if (vfoActive == VFO_B) {
-      setFrequency(rigState.vfo[1]);
-    }
-  }
-  
+  updateRaduinoFromState(rigState);
+    
   //S-Meter Display
   if (((displayOption1 & 0x08) == 0x08 && (sdrModeOn == 0)) && (++checkCountSMeter > SMeterLatency))
   {

Raduino/ubitx_ui.ino

@@ -350,3 +350,41 @@ void doRaduinoToTeensy(UBitxRigState* r) {
   Serial.print(len);
   Serial.println();
 }
+
+void updateStateFromRaduino(UBitxRigState& r) {
+  // Note, we really need to be checking a dirty flag for this.  But, I don't have a dirty flag in this version of the data type...
+  if (vfoActive == VFO_A) {
+    rigState.vfo[0] = frequency;
+    rigState.flags &= ~UBITX_VFOB_FLAG;
+  } else if (vfoActive == VFO_B) {
+    rigState.vfo[1] = frequency;
+    rigState.flags |= UBITX_VFOB_FLAG;
+  } 
+  rigState.rit = ritRxFrequency - frequency;
+  rigState.flags = 0;
+  rigState.flags |= (vfoActive == VFO_B ? UBITX_VFOB_FLAG : 0);
+  rigState.flags |= (cwMode != 0 ? UBITX_CW_FLAG : 0);
+  rigState.flags |= (isUSB != 0 ? UBITX_USB_FLAG : 0);
+  rigState.flags |= (splitOn != 0 ? UBITX_SPLIT_FLAG : 0);
+  rigState.flags |= (ritOn != 0 ? UBITX_RIT_FLAG : 0);
+}
+
+void updateRaduinoFromState(UBitxRigState& r) {
+  vfoActive = rigState.flags & UBITX_VFOB_FLAG ? VFO_B : VFO_A;
+  if (vfoActive == VFO_A) {
+    if (rigState.vfo[0] != frequency) {
+      setFrequency(rigState.vfo[0]);
+    } else if (vfoActive == VFO_B) {
+      setFrequency(rigState.vfo[1]);
+    }
+  }
+  ritRxFrequency = frequency + rigState.rit;
+  splitOn = rigState.flags & UBITX_SPLIT_FLAG ? 1 : 0;
+  ritOn = rigState.flags & UBITX_RIT_FLAG ? 1 : 0;
+  isUSB = rigState.flags & UBITX_USB_FLAG ? 1 : 0;
+  if (rigState.flags & UBITX_CW_FLAG) {    
+    cwMode = isUSB ? 2 : 1; // 2 = cwu / 1 = cwl
+  } else {
+    cwMode = 0;
+  }
+}

TeensyDSP/RigState.h

@@ -25,4 +25,150 @@ struct UBitxRigState {
   uint32_t flags = 0;
 };
 
+/**********************************************************************/
+
+template<typename T, int ID>
+struct Field {
+  byte id = ID;
+  bool dirty;
+  T data;
+
+  inline size_t sizeOfWrite() { return dirty ? sizeof(byte) + sizeof(T) : 0; }
+  
+  template<typename STREAM> void writeChanges() {
+    if (dirty) {
+      STREAM().write(id);
+      STREAM().write((byte*)&data, sizeof(T));
+    }
+  }
+
+  template<typename STREAM> int read() {
+    size_t len = 0;
+    byte* ptr = (byte*)&data;
+    while (STREAM().available() && len < sizeof(T)) {
+      ptr[len++] = STREAM().read();
+    }
+    return len;
+  }
+
+  inline void merge(Field<T,ID>& f) {
+    if (dirty) {
+      f.data = data;
+      f.dirty = true;
+    } else if (f.dirty) {
+      data = f.data;
+      dirty = true;
+    }
+  }
+
+  inline void markClean() { dirty = false; }
+};
+
+struct RigState {
+  Field<uint32_t, 0>  vfoA;
+  Field<uint32_t, 1>  vfoB;
+  Field<int32_t, 2>   rit;
+  Field<int32_t, 3>   xit;
+  Field<uint32_t, 4>  flags;
+
+  inline size_t sizeOfWrite() {
+    size_t size = 0;
+    size += vfoA.sizeOfWrite();
+    size += vfoB.sizeOfWrite();
+    size += rit.sizeOfWrite();
+    size += xit.sizeOfWrite();
+    size += flags.sizeOfWrite();
+    return size;
+  }
+
+  template<typename STREAM> void writeChanges() {
+    vfoA.writeChanges<STREAM>();
+    vfoB.writeChanges<STREAM>();
+    rit.writeChanges<STREAM>();
+    xit.writeChanges<STREAM>();
+    flags.writeChanges<STREAM>();
+  }
+
+  template<typename STREAM> void readChanges(size_t size) {
+    size_t len = 0;
+    while (STREAM().available() && len < size) {
+      switch(STREAM().read()) {
+        case 0:
+        len += vfoA.read<STREAM>();
+        break;
+        
+        case 1:
+        len += vfoB.read<STREAM>();
+        break;
+        
+        case 2:
+        len += rit.read<STREAM>();
+        break;
+        
+        case 3:
+        len += xit.read<STREAM>();
+        break;
+
+        case 4:
+        len += flags.read<STREAM>();
+        break;
+
+        default:
+        ;        
+      }
+    }
+  }
+
+  inline void merge(RigState& r) {
+    vfoA.merge(r.vfoA);
+    vfoB.merge(r.vfoB);
+    rit.merge(r.rit);
+    xit.merge(r.xit);
+    flags.merge(r.flags);
+  }
+
+  inline void markClean(RigState& r) {
+    vfoA.markClean();
+    vfoB.markClean();
+    rit.markClean();
+    xit.markClean();
+    flags.markClean();
+  }
+};
+
+/*
+Protocol discussion:
+- I2C master: Raduino
+- I2C slave:  TeensyDSP
+
+Raduino state:
+  - Baseline uBITX variables
+  - I2C buffer
+    - On I2C transmit:  make updates based on current variables
+    - On I2C receive:
+      - Update based on received I2C responses
+      - Update associated variables
+    
+TeensyDSP state:
+  - CAT buffer
+    - Used to receive command from CAT (when commands arrive via Serial)
+    - Used to transmit state to Raduino (when requested via Wire1)
+  - Raduino buffer
+    - Used to receive state from Raduino (when received via Wire1)
+    - Used to transmit responses to CAT (over Serial)
+  - Questions
+    - How can these be synchronized?
+      - At the tail end of an I2C request handler.  Before sending the response to the Raduino via I2C:
+        - Copy updated CAT buffer items to the Raduino buffer.
+        - Copy updated Raduino buffer items to the CAT buffer.
+        - In the case of conflicts, CAT wins.
+        - Transmit the CAT buffer state to the Raduino.
+- TeensyDSP updates 'outgoing' state based on CAT inputs.
+  - Make change to data.
+  - Mark data as dirty, if different than incoming state.
+- When requested, Teensy DSP sends 'outgoing' state to Raduino.
+  - Send dirty data over I2C.
+  - Mark data as clean.  
+ */
+ 
 #endif