Support for multiple displays (OLED etc).

New EXRAIL command LCD2(display,row,"text").  Display 0 is the usual one, other displays can be configured through HAL.

DIAG.h

@@ -24,4 +24,5 @@
 #include "StringFormatter.h"
 #define DIAG  StringFormatter::diag
 #define LCD   StringFormatter::lcd
+#define LCD2  StringFormatter::lcd
 #endif

DisplayInterface.h

@@ -30,6 +30,16 @@ public:
   virtual void setRow(byte line) { (void)line; };
   virtual void clear() { };
   virtual size_t write(uint8_t c) { (void)c; return 0; };
+  // Additional functions to support multiple displays.
+  // Display number zero is the default one and the original display
+  // drivers overloaded the above calls only.  Newer display drivers
+  // (e.g. HAL IO_OledDisplay) should override all functions.
+  virtual void setRow(uint8_t displayNo, byte line) { 
+    if (!displayNo) setRow(line);
+  }
+  virtual void clear(uint8_t displayNo) { 
+    if (!displayNo) clear();
+   }
 
   static DisplayInterface *lcdDisplay;
 };

EXRAIL2.cpp

@@ -1209,6 +1209,7 @@ void RMFT2::thrungeString(uint32_t strfar, thrunger mode, byte id) {
     case thrunge_parse:
     case thrunge_broadcast:
     case thrunge_lcd:
+    default:    // thrunge_lcd+1, ...
          if (!buffer) buffer=new StringBuffer();
          buffer->flush();
          stream=buffer;
@@ -1244,7 +1245,9 @@ void RMFT2::thrungeString(uint32_t strfar, thrunger mode, byte id) {
     case thrunge_lcd:
          LCD(id,F("%s"),buffer->getString());
          break;
-
-     default: break;       
+    default:  // thrunge_lcd+1, ...
+      if (mode > thrunge_lcd) 
+        LCD2(mode-thrunge_lcd, id, F("%s"),buffer->getString());  // print to other display
+      break;       
     }
 }

EXRAIL2.h

@@ -73,11 +73,15 @@ enum OPCODE : byte {OPCODE_THROW,OPCODE_CLOSE,
              OPCODE_IFLOCO
              };
 
+// Ensure thrunge_lcd is put last as there may be more than one display, 
+// sequentially numbered from thrunge_lcd.
 enum thrunger: byte {
   thrunge_print, thrunge_broadcast, thrunge_serial,thrunge_parse,
   thrunge_serial1, thrunge_serial2, thrunge_serial3,
   thrunge_serial4, thrunge_serial5, thrunge_serial6,
-  thrunge_lcd, thrunge_lcn};
+  thrunge_lcn, 
+  thrunge_lcd,  // Must be last!!
+  };
 
 
  

EXRAIL2MacroReset.h

@@ -80,6 +80,7 @@
 #undef KILLALL
 #undef LATCH 
 #undef LCD 
+#undef LCD2
 #undef LCN 
 #undef MOVETT
 #undef ONACTIVATE
@@ -199,6 +200,7 @@
 #define KILLALL
 #define LATCH(sensor_id) 
 #define LCD(row,msg)
+#define LCD2(display,row,msg)
 #define LCN(msg) 
 #define MOVETT(id,steps,activity)
 #define ONACTIVATE(addr,subaddr)

EXRAILMacros.h

@@ -45,7 +45,7 @@
 // Descriptive texts for routes and animations are created in a sepaerate function which
 // can be called to emit a list of routes/automatuions in a form suitable for Withrottle. 
  
-// PRINT(msg) and LCD(row,msg) is implemented in a separate pass to create 
+// PRINT(msg), LCD(row,msg) and LCD2(display,row,msg) are implemented in a separate pass to create 
 // a getMessageText(id) function.  
 
 // CAUTION: The macros below are multiple passed over myAutomation.h
@@ -143,6 +143,15 @@ const int StringMacroTracker1=__COUNTER__;
          lcdid=id;\
          break;\
       }
+#undef LCD2
+#define LCD2(display,id,msg)  \
+     case (__COUNTER__ - StringMacroTracker1) : {\
+         static const char HIGHFLASH thrunge[]=msg;\
+         strfar=(uint32_t)GETFARPTR(thrunge);\
+         tmode=(thrunger)(thrunge_lcd+display); \
+         lcdid=id;\
+         break;\
+      } 
 
 void  RMFT2::printMessage(uint16_t id) { 
   thrunger tmode;
@@ -298,6 +307,7 @@ const  HIGHFLASH  int16_t RMFT2::SignalDefinitions[] = {
 #define KILLALL OPCODE_KILLALL,0,0,
 #define LATCH(sensor_id) OPCODE_LATCH,V(sensor_id),
 #define LCD(id,msg) PRINT(msg)
+#define LCD2(display,id,msg)
 #define LCN(msg) PRINT(msg)
 #define MOVETT(id,steps,activity) OPCODE_SERVO,V(id),OPCODE_PAD,V(steps),OPCODE_PAD,V(EXTurntable::activity),OPCODE_PAD,V(0),
 #define ONACTIVATE(addr,subaddr) OPCODE_ONACTIVATE,V(addr<<2|subaddr),
@@ -368,6 +378,8 @@ const  HIGHFLASH  byte RMFT2::RouteCode[] = {
 // Restore normal code LCD & SERIAL  macro
 #undef LCD
 #define LCD   StringFormatter::lcd
+#undef LCD2
+#define LCD2  StringFormatter::lcd
 #undef SERIAL
 #define SERIAL  0x0
 #endif

IO_OLEDDisplay.h

@@ -51,6 +51,7 @@
 
 class OLEDDisplay : public IODevice, DisplayInterface {
 private:
+  uint8_t _displayNo = 0;
   // Here we define the device-specific variables.  
   uint8_t _height; // in pixels
   uint8_t _width;  // in pixels
@@ -64,16 +65,22 @@ private:
   uint8_t *_lastRowGeneration = NULL;
   uint8_t _rowNoToScreen = 0; 
   uint8_t _charPosToScreen = 0;
+  DisplayInterface *_nextDisplay = NULL;
+  uint8_t _selectedDisplayNo = 0;
 
 public:
   //  Static function to handle "OLEDDisplay::create(...)" calls.
   static void create(I2CAddress i2cAddress, int width = 128, int height=64) {
-    /* if (checkNoOverlap(i2cAddress)) */ new OLEDDisplay(i2cAddress, width, height);
+    /* if (checkNoOverlap(i2cAddress)) */ new OLEDDisplay(0, i2cAddress, width, height);
+  } 
+  static void create(uint8_t displayNo, I2CAddress i2cAddress, int width = 128, int height=64) {
+    /* if (checkNoOverlap(i2cAddress)) */ new OLEDDisplay(displayNo, i2cAddress, width, height);
   } 
 
 protected:
   // Constructor
-  OLEDDisplay(I2CAddress i2cAddress, int width, int height) {
+  OLEDDisplay(uint8_t displayNo, I2CAddress i2cAddress, int width, int height) {
+    _displayNo = displayNo;
     _I2CAddress = i2cAddress;
     _width = width;
     _height = height;
@@ -89,9 +96,26 @@ protected:
     // Fill buffer with spaces
     memset(_buffer, ' ', _numCols*_numRows);
 
+    // Is this the main display?
+    if (_displayNo == 0) {
+      // Set first two lines on screen
+      setRow(0);
+      print(F("DCC++ EX v"));
+      print(F(VERSION));
+      setRow(1);
+      print(F("Lic GPLv3"));
+    }
+
     // Create OLED driver
     oled = new SSD1306AsciiWire();
    
+    // Store pointer to this object into CS display hook, so that we
+    // will intercept any subsequent calls to lcdDisplay methods.
+    // Make a note of the existing display reference, to that we can
+    // pass on anything we're not interested in.
+    _nextDisplay = DisplayInterface::lcdDisplay;
+    DisplayInterface::lcdDisplay = this;
+
     addDevice(this);
   }
   
@@ -99,15 +123,9 @@ protected:
   void _begin() override {
     // Initialise device
     if (oled->begin(_I2CAddress, _width, _height)) {
-      // Store pointer to this object into CS display hook, so that we
-      // will intercept any subsequent calls to lcdDisplay methods.
-      DisplayInterface::lcdDisplay = this;
 
       DIAG(F("OLEDDisplay installed on address %s"), _I2CAddress.toString());
 
-      // Set first two lines on screen
-      LCD(0,F("DCC++ EX v%S"),F(VERSION));
-      LCD(1,F("Lic GPLv3"));
 
       // Force all rows to be redrawn
       for (uint8_t row=0; row<_numRows; row++)
@@ -120,7 +138,10 @@ protected:
   }
 
   void _loop(unsigned long) override {
+    screenUpdate();
+  }
 
+  void screenUpdate() {
     // Loop through the buffer and if a row has changed
     // (rowGeneration[row] is changed) then start writing the
     // characters from the buffer, one character per entry, 
@@ -156,16 +177,23 @@ protected:
   // 
   /////////////////////////////////////////////////
   DisplayInterface* loop2(bool force) override {
-    (void)force;   // suppress compiler warning
+    //screenUpdate();
+    if (_nextDisplay) 
+      return _nextDisplay->loop2(force);  // continue to next display
     return NULL;
   }
 
   // Position on nominated line number (0 to number of lines -1)
   // Clear the line in the buffer ready for updating
-  void setRow(byte line) override {
+  // The displayNo referenced here is remembered and any following
+  // calls to write() will be directed to that display.
+  void setRow(uint8_t displayNo, byte line) override {
+    _selectedDisplayNo = displayNo;
+    if (displayNo == _displayNo) {
       if (line == 255) {
-      // LCD(255, "xxx") - scroll the contents of the buffer
-      // and put the new line at the bottom of the screen
+        // LCD(255,"xxx") or LCD2(displayNo,255, "xxx") - 
+        // scroll the contents of the buffer and put the new line
+        // at the bottom of the screen
         for (int row=1; row<_numRows; row++) {
           strncpy(&_buffer[(row-1)*_numCols], &_buffer[row*_numCols], _numCols);
           _rowGeneration[row-1]++;
@@ -182,28 +210,49 @@ protected:
       // Mark that the buffer has been touched.  It will be 
       // sent to the screen on the next loop entry.
       _rowGeneration[_rowNo]++;
+
+    } else if (_nextDisplay) 
+      _nextDisplay->setRow(displayNo, line); // Pass to next display
+
+  }
+
+  // Write one character to the screen referenced in the last setRow() call.
+  size_t write(uint8_t c) override {
+    if (_selectedDisplayNo == _displayNo) {
+      // Write character to buffer (if there's space)
+      if (_colNo < _numCols) {
+        _buffer[_rowNo*_numCols+_colNo++] = c;
+      }
+      return 1;
+    } else if (_nextDisplay) 
+      return _nextDisplay->write(c);
+    else
+      return 0;
   }
 
   // Write blanks to all of the screen (blocks until complete)
-  void clear () override {
+  void clear (uint8_t displayNo) override {
+    if (displayNo == _displayNo) {
       // Clear buffer
       for (_rowNo = 0; _rowNo < _numRows; _rowNo++) {
-      setRow(_rowNo);
+        setRow(displayNo, _rowNo);
       }
       _rowNo = 0;
+    } else if (_nextDisplay)
+      _nextDisplay->clear(displayNo);  // Pass to next display
   }
   
-  // Write one character
-  size_t write(uint8_t c) override {
-    // Write character to buffer (if space)
-    if (_colNo < _numCols)
-      _buffer[_rowNo*_numCols+_colNo++] = c;
-    return 1;
+  // Overloads of above, for compatibility
+  void setRow(uint8_t line) override {
+    setRow(0, line);
+  }
+  void clear() override {
+    clear(0);
   }
 
   // Display information about the device.
   void _display() {
-    DIAG(F("OLEDDisplay Configured addr %s"), _I2CAddress.toString());
+    DIAG(F("OLEDDisplay %d Configured addr %s"), _displayNo, _I2CAddress.toString());
   }
 
 };

StringFormatter.cpp

@@ -51,6 +51,16 @@ void StringFormatter::lcd(byte row, const FSH* input...) {
   send2(LCDDisplay::lcdDisplay,input,args);
 }
 
+void StringFormatter::lcd(uint8_t display, byte row, const FSH* input...) {
+  va_list args;
+
+  if (!LCDDisplay::lcdDisplay) return;
+  LCDDisplay::lcdDisplay->setRow(display, row);    
+  va_start(args, input);
+  send2(LCDDisplay::lcdDisplay,input,args);
+  va_end(args);
+}
+
 void StringFormatter::send(Print * stream, const FSH* input...) {
   va_list args;
   va_start(args, input);

StringFormatter.h

@@ -46,6 +46,7 @@ class StringFormatter
     // DIAG support
     static void diag( const FSH* input...);
     static void lcd(byte row, const FSH* input...);
+    static void lcd(uint8_t display, byte row, const FSH* input...);
     static void printEscapes(char * input);
     static void printEscape( char c);