Additional ADC options

Author: microbuilder

cores/nRF5/wiring_analog.h

@@ -32,8 +32,12 @@ extern "C" {
 typedef enum _eAnalogReference
 {
   AR_DEFAULT,
-  AR_INTERNAL,
-  AR_VDD4
+  AR_INTERNAL,          // 0.6V Ref * 6 = 0..3.6V
+  AR_INTERNAL_3_0,      // 0.6V Ref * 5 = 0..3.0V
+  AR_INTERNAL_2_4,      // 0.6V Ref * 4 = 0..2.4V
+  AR_INTERNAL_1_8,      // 0.6V Ref * 3 = 0..1.8V
+  AR_INTERNAL_1_2,      // 0.6V Ref * 2 = 0..1.6V
+  AR_VDD4               // VDD/4 REF * 4 = 0..VDD
 } eAnalogReference ;
 #else
 typedef enum _eAnalogReference

cores/nRF5/wiring_analog_nRF52.c

@@ -90,17 +90,33 @@ static inline uint32_t mapResolution( uint32_t value, uint32_t from, uint32_t to
 void analogReference( eAnalogReference ulMode )
 {
   switch ( ulMode ) {
+    case AR_VDD4:
+      saadcReference = SAADC_CH_CONFIG_REFSEL_VDD1_4;
+      saadcGain      = SAADC_CH_CONFIG_GAIN_Gain4;
+      break;
+    case AR_INTERNAL_3_0:
+      saadcReference = SAADC_CH_CONFIG_REFSEL_Internal;
+      saadcGain      = SAADC_CH_CONFIG_GAIN_Gain1_5;
+      break;
+    case AR_INTERNAL_2_4:
+      saadcReference = SAADC_CH_CONFIG_REFSEL_Internal;
+      saadcGain      = SAADC_CH_CONFIG_GAIN_Gain1_4;
+      break;
+    case AR_INTERNAL_1_8:
+      saadcReference = SAADC_CH_CONFIG_REFSEL_Internal;
+      saadcGain      = SAADC_CH_CONFIG_GAIN_Gain1_3;
+      break;
+    case AR_INTERNAL_1_2:
+      saadcReference = SAADC_CH_CONFIG_REFSEL_Internal;
+      saadcGain      = SAADC_CH_CONFIG_GAIN_Gain1_2;
+      break;
     case AR_DEFAULT:
     case AR_INTERNAL:
     default:
       saadcReference = SAADC_CH_CONFIG_REFSEL_Internal;
       saadcGain      = SAADC_CH_CONFIG_GAIN_Gain1_6;
       break;
 
-    case AR_VDD4:
-      saadcReference = SAADC_CH_CONFIG_REFSEL_VDD1_4;
-      saadcGain      = SAADC_CH_CONFIG_GAIN_Gain1_4;
-      break;
   }
 }