Added concentric rotary encoder emulation

New class to allow emulation of concentric rotary encoders using single shaft encoders with integrated push buttons. Retains methods and style from RotaryEncoderT.

Example usage (A-10C):
typedef DcsBios::EmulatedConcentricRotaryEncoderT<POLL_EVERY_TIME, DcsBios::FOUR_STEPS_PER_DETENT> EmulatedConcentricRotaryEncoder;
EmulatedConcentricRotaryEncoder ilsRightKnob("ILS_KHZ", "DEC", "INC", "ILS_VOL", "-4500", "+4500", DATAPIN, CLKPIN, SWPIN);

Author: AerialElectron

src/internal/Encoders.h

@@ -292,6 +292,112 @@ namespace DcsBios {
   };
   typedef MatRotaryEncoderT<> MatRotaryEncoder;
 
+  	//To emulate dual concentric rotary encoders/resolvers/potentiometers using a rotary encoder with a push button.
+	//Secondary message is used when push button or switch is enabled.
+
+	template <unsigned long pollIntervalMs = POLL_EVERY_TIME, StepsPerDetent stepsPerDetent = ONE_STEP_PER_DETENT>
+	class EmulatedConcentricRotaryEncoderT : PollingInput, public ResettableInput {
+	private:
+		const char* msg1_;	//Function 1 (default)
+		const char* decArg1_;
+		const char* incArg1_;
+		const char* msg2_;	//Function 2
+		const char* decArg2_;
+		const char* incArg2_;
+		char pinA_;
+		char pinB_;
+		char pinC_;	//Integrated button pin
+		bool msg1Mode_;
+		char prevMode_;
+		char lastState_;
+		signed char delta_;
+		
+		char readState() {
+			return (digitalRead(pinA_) << 1) | digitalRead(pinB_);
+		}
+		
+		void checkPress() {
+			char currentMode;
+			msg1Mode_ = ((currentMode = digitalRead(pinC_)) != prevMode_)?!msg1Mode_:msg1Mode_;
+			prevMode_ = currentMode;
+		}
+		
+		void resetState() {
+			lastState_ = (lastState_==0)?-1:0;
+		}
+		
+		void pollInput() {
+			char state = readState();
+			checkPress();
+			switch(lastState_) {
+				case 0:
+					if (state == 2) delta_--;
+					if (state == 1) delta_++;
+					break;
+				case 1:
+					if (state == 0) delta_--;
+					if (state == 3) delta_++;
+					break;
+				case 2:
+					if (state == 3) delta_--;
+					if (state == 0) delta_++;
+					break;
+				case 3:
+					if (state == 1) delta_--;
+					if (state == 2) delta_++;
+					break;
+			}
+			lastState_ = state;
+			
+			if ((delta_ >= stepsPerDetent) && (msg1Mode_)) {
+				if (tryToSendDcsBiosMessage(msg1_, incArg1_))
+					delta_ -= stepsPerDetent;
+			}
+			if ((delta_ <= -stepsPerDetent) && (msg1Mode_)) {
+				if (tryToSendDcsBiosMessage(msg1_, decArg1_))
+					delta_ += stepsPerDetent;
+			}
+			if ((delta_ >= stepsPerDetent) && (!msg1Mode_)) {
+				if (tryToSendDcsBiosMessage(msg2_, incArg2_))
+					delta_ -= stepsPerDetent;
+			}
+			if ((delta_ <= -stepsPerDetent) && (!msg1Mode_)) {
+				if (tryToSendDcsBiosMessage(msg2_, decArg2_))
+					delta_ += stepsPerDetent;
+			}
+		}
+	public:
+		EmulatedConcentricRotaryEncoderT(const char* msg1, const char* decArg1, const char* incArg1, const char* msg2, const char* decArg2, const char* incArg2, char pinA, char pinB, char pinC) :
+			PollingInput(pollIntervalMs) {
+			msg1_ = msg1;
+			decArg1_ = decArg1;
+			incArg1_ = incArg1;
+			msg2_ = msg2;
+			decArg2_ = decArg2;
+			incArg2_ = incArg2;
+			pinA_ = pinA;
+			pinB_ = pinB;
+			pinC_ = pinC;
+			msg1Mode_ = true;
+			prevMode_ = 1;
+			pinMode(pinA_, INPUT_PULLUP);
+			pinMode(pinB_, INPUT_PULLUP);
+			pinMode(pinC_, INPUT_PULLUP);
+			prevMode_ = digitalRead(pinC_);	//Prevents defaulting to secondary action on initialization
+			delta_ = 0;
+			lastState_ = readState();
+		}
+
+		void SetControl(const char* msg) {	
+			msg1_ = msg;
+		}
+		
+        
+		void resetThisState() {
+			this->resetState();
+		}
+	};
+	typedef EmulatedConcentricRotaryEncoderT<> EmulatedConcentricRotaryEncoder;
 }
 
 #endif