pins_arduino.h: small changes to analogInputToDigitalPin()

Author: Roy, Elizabeth

variants/uno2018/pins_arduino.h

@@ -31,7 +31,8 @@
 #define NUM_OCCUPIED_PINS			6 // (TOSC1/2, VREF, RESET, DEBUG USART Rx/Tx)
 #define NUM_TOTAL_FREE_PINS			(NUM_DIGITAL_PINS + NUM_ANALOG_INPUTS + NUM_TESTPOINT_PINS)	
 #define NUM_TOTAL_PINS				(NUM_DIGITAL_PINS + NUM_ANALOG_INPUTS + NUM_TESTPOINT_PINS + NUM_OCCUPIED_PINS)
-#define analogInputToDigitalPin(p)  ((p < 6) ? (p) + 14 : NOT_A_PIN)
+#define ANALOG_INPUT_OFFSET			14
+#define analogInputToDigitalPin(p)  ((p < NUM_ANALOG_INPUTS) ? (p) + ANALOG_INPUT_OFFSET : NOT_A_PIN)
 
 #define digitalPinHasPWM(p)         ((p) == 3 || (p) == 5 || (p) == 6 || (p) == 9 || (p) == 10 || (p) == 11)