Add a way to read the attached pin no for servos

libraries/Servo/src/Servo.h

@@ -102,7 +102,8 @@ class Servo
   void writeMicroseconds(int value); // Write pulse width in microseconds 
   int read();                        // returns current pulse width as an angle between 0 and 180 degrees
   int readMicroseconds();            // returns current pulse width in microseconds for this servo (was read_us() in first release)
-  bool attached();                   // return true if this servo is attached, otherwise false 
+  bool attached();                   // return true if this servo is attached, otherwise false
+  int getAttachedPin();              // returns the pin the servo is attached to.
 private:
    uint8_t servoIndex;               // index into the channel data for this servo
    int8_t min;                       // minimum is this value times 4 added to MIN_PULSE_WIDTH    

libraries/Servo/src/avr/Servo.cpp

@@ -313,5 +313,13 @@ bool Servo::attached()
   return servos[this->servoIndex].Pin.isActive ;
 }
 
+int Servo::getAttachedPin()
+{
+  if (this->servoIndex != INVALID_SERVO)
+    return servos[this->servoIndex].Pin.nbr;
+  else
+    return 0;
+}
+
 #endif // ARDUINO_ARCH_AVR
 

libraries/Servo/src/sam/Servo.cpp

@@ -279,5 +279,13 @@ bool Servo::attached()
   return servos[this->servoIndex].Pin.isActive;
 }
 
+int Servo::getAttachedPin()
+{
+  if (this->servoIndex != INVALID_SERVO)
+    return servos[this->servoIndex].Pin.nbr;
+  else
+    return 0;
+}
+
 #endif // ARDUINO_ARCH_SAM
 

libraries/Servo/src/samd/Servo.cpp

@@ -294,4 +294,12 @@ bool Servo::attached()
   return servos[this->servoIndex].Pin.isActive;
 }
 
+int Servo::getAttachedPin()
+{
+  if (this->servoIndex != INVALID_SERVO)
+    return servos[this->servoIndex].Pin.nbr;
+  else
+    return 0;
+}
+
 #endif // ARDUINO_ARCH_SAMD