Examples: Add dual ADC mode example.

examples/Advanced/ADC_Dual_Mode/ADC_Dual_Mode.ino

@@ -0,0 +1,42 @@
+#include <Arduino_AdvancedAnalog.h>
+
+AdvancedADC adc1(A0, A1);
+AdvancedADC adc2(A2, A3);
+AdvancedADCDual adc_dual(adc1, adc2);
+uint64_t last_millis = 0;
+
+void setup() {
+    Serial.begin(9600);
+    while (!Serial) {
+    }
+
+    // Resolution, sample rate, number of samples per channel, queue depth.
+    if (!adc_dual.begin(AN_RESOLUTION_16, 16000, 32, 32)) {
+        Serial.println("Failed to start analog acquisition!");
+        while (1);
+    }
+}
+
+void loop() {
+    if (adc1.available()) {
+        SampleBuffer buf1 = adc1.read();
+        SampleBuffer buf2 = adc2.read();
+
+        // Process the buffer.
+        if (millis() - last_millis > 1) {
+            Serial.println(buf1.timestamp());  // Print buffer timestamp
+            Serial.println(buf1[0]);           // Print sample from first channel
+            Serial.println(buf1[1]);           // Print sample from second channel
+
+            Serial.println(buf2.timestamp());  // Print buffer timestamp
+            Serial.println(buf2[0]);           // Print sample from first channel
+            Serial.println(buf2[1]);           // Print sample from second channel
+
+            last_millis = millis();
+        }
+
+        // Release the buffer to return it to the pool.
+        buf1.release(); 
+        buf2.release();
+    }
+}