Merge branch 'adc_channel' into hyperfirmata

Author: carlosperate

cores/nRF5/wiring_analog_nRF51.c

@@ -132,6 +132,16 @@ uint32_t analogRead( uint32_t ulPin )
   uint32_t resolution;
   int16_t value;
 
+#ifdef ARDUINO_ADC_NON_STANDARD_PINS
+  ulPin = _analogChannelPin(ulPin);
+#elif NUM_ANALOG_INPUTS > 0
+  if (ulPin < A0) {
+    ulPin += A0;
+  }
+#else
+  return 0;
+#endif
+
   if (ulPin >= PINS_COUNT) {
     return 0;
   }

variants/BBCmicrobit/variant.h

@@ -40,7 +40,6 @@ extern "C"
 // LEDs
 #define PIN_LED                 (13)
 #define LED_BUILTIN             PIN_LED
-// #define
 
 // Buttons
 #define PIN_BUTTON_A            (5)
@@ -65,6 +64,23 @@ static const uint8_t A4  = PIN_A4 ;
 static const uint8_t A5  = PIN_A5 ;
 #define ADC_RESOLUTION    10
 
+// Non standard distribution of Analog Pins requires a lookup table
+#define ARDUINO_ADC_NON_STANDARD_PINS
+__inline__ uint32_t _analogChannelPin(uint32_t pin) __attribute__((always_inline));
+__inline__ uint32_t _analogChannelPin(uint32_t pin) {
+  switch (pin) {
+    case 0:  return PIN_A0;
+    case 1:  return PIN_A1;
+    case 2:  return PIN_A2;
+    case 3:  return PIN_A3;
+    case 4:  return PIN_A4;
+    case 5:  return PIN_A5;
+    case 10: return PIN_A5;
+    // Otherwise non-analog pin so return out of range pin to exit early
+    default: return PINS_COUNT;
+  }
+}
+
 /*
  * Serial interfaces
  */