Add channel 17 for VRef

Author: bcostm

targets/TARGET_STM/TARGET_STM32F2/TARGET_NUCLEO_F207ZG/PeripheralPins.c

@@ -88,6 +88,7 @@ const PinMap PinMap_ADC[] = {
     {PF_9,  ADC_3, STM_PIN_DATA_EXT(STM_MODE_ANALOG, GPIO_NOPULL, 0, 7, 0)},  // ADC3_IN7
     {PF_10, ADC_3, STM_PIN_DATA_EXT(STM_MODE_ANALOG, GPIO_NOPULL, 0, 8, 0)}, // ADC3_IN8
     {ADC_TEMP, ADC_1, STM_PIN_DATA_EXT(STM_MODE_ANALOG, GPIO_NOPULL, 0, 16, 0)}, // ADC1_IN16
+    {ADC_VREF, ADC_1, STM_PIN_DATA_EXT(STM_MODE_ANALOG, GPIO_NOPULL, 0, 17, 0)}, // ADC1_IN17
     {NC,   NC,    0}
 };
 

targets/TARGET_STM/TARGET_STM32F2/TARGET_NUCLEO_F207ZG/PinNames.h

@@ -201,6 +201,7 @@ typedef enum {
 
     // ADC internal channels
     ADC_TEMP = 0xF0,
+    ADC_VREF = 0xF1,
 
     // Arduino connector namings
     A0          = PA_3,

targets/TARGET_STM/TARGET_STM32F2/analogin_api.c

@@ -58,8 +58,8 @@ void analogin_init(analogin_t *obj, PinName pin)
     MBED_ASSERT(function != (uint32_t)NC);
     obj->channel = STM_PIN_CHANNEL(function);
 
-    // Configure GPIO excepted for internal channels (Temperature)
-    if (obj->channel != 16) {
+    // Configure GPIO excepted for internal channels (Temperature, Vref)
+    if ((obj->channel != 16) && (obj->channel != 17)) {
         pinmap_pinout(pin, PinMap_ADC);
     }
 
@@ -171,6 +171,9 @@ static inline uint16_t adc_read(analogin_t *obj)
         case 16:
             sConfig.Channel = ADC_CHANNEL_16;
             break;
+        case 17:
+            sConfig.Channel = ADC_CHANNEL_17;
+            break;
         default:
             return 0;
     }