analogWrite: implement DAC pins

Author: facchinm

cores/arduino/Arduino.h

@@ -64,6 +64,17 @@ enum dacPins { DT_FOREACH_PROP_ELEM(DT_PATH(zephyr_user), dac_channels, DAC_ENUM
 
 #endif
 
+#ifdef CONFIG_DAC
+
+#undef DAC0
+#undef DAC1
+#undef DAC2
+#undef DAC3
+#define DAC_ENUMS(n, p, i) DAC ## i = i,
+enum dacPins { DT_FOREACH_PROP_ELEM(DT_PATH(zephyr_user), dac_channels, DAC_ENUMS) NUM_OF_DACS };
+
+#endif
+
 void interrupts(void);
 void noInterrupts(void);
 

cores/arduino/zephyrCommon.cpp

@@ -329,6 +329,16 @@ int analogWriteResolution() {
 }
 #endif
 
+#if defined(CONFIG_DAC) || defined(CONFIG_PWM)
+static int _analog_write_resolution = 8;
+void analogWriteResolution(int bits) {
+    _analog_write_resolution = bits;
+}
+int analogWriteResolution() {
+  return _analog_write_resolution;
+}
+#endif
+
 #ifdef CONFIG_PWM
 
 void analogWrite(pin_size_t pinNumber, int value)