Add proejct 4, for ADC and capacitive touch sensors

04-adc/04-adc.ino

@@ -0,0 +1,46 @@
+#define PIN_ANALOG_IN 1
+#define ADC_PRECISION 12
+#define ADC_MAX       (double)(1 << ADC_PRECISION)
+#define ADC_VOLTAGE   3.3
+#define PIN_LED_TOUCH         21
+#define TOUCH_PRESS_MIN       132000
+#define TOUCH_PRESS_RELEASE   65535
+#define PIN_LED_FADE          19
+int touchProcessed = 0;
+int ledState = 0;
+
+void setup() {
+  // put your setup code here, to run once:
+  Serial.begin(115200);
+  pinMode(PIN_LED_TOUCH, OUTPUT);
+  ledcAttach(PIN_LED_FADE, 1000, 12);
+}
+
+void loop() {
+  // put your main code here, to run repeatedly:
+  int adcvalue = analogRead(PIN_ANALOG_IN);
+  double voltage = adcvalue / ADC_MAX * ADC_VOLTAGE;
+  Serial.printf("ADC value : %d\tVoltage: %.2fV\r\n", adcvalue, voltage);
+  Serial.printf("Touch value: %d \r\n", touchRead(T14));
+
+  if ( touchRead(T14) > TOUCH_PRESS_MIN  ) {
+    if ( touchProcessed == 0 ) {
+      touchProcessed = 1;
+      if ( ledState == 0 ) {
+        digitalWrite(PIN_LED_TOUCH, HIGH);
+        ledState = 1;
+      } else { 
+        digitalWrite(PIN_LED_TOUCH, LOW);
+        ledState = 0;
+      }
+    }
+  }
+
+  if ( touchRead(T14) < TOUCH_PRESS_RELEASE ) {
+    if ( touchProcessed == 1 ) {
+      touchProcessed = 0;
+    }
+  }
+  ledcWrite(PIN_LED_FADE, analogRead(PIN_ANALOG_IN));
+  delay(200);
+}