Add analogReadDMA example

examples/Analog/analogReadDMA/analogReadDMA.ino

@@ -0,0 +1,50 @@
+/*
+  analogReadDMA
+
+  This sketch shows how to use analogReadDMA() method.
+
+  analogReadDMA uses ADC with DMA to read samples and increases sampling rate.
+*/
+
+// Define the number of sample to read
+#define NB_SAMPLE 16
+
+// Array where save the samples
+uint32_t samples[NB_SAMPLE] = {0};
+
+// callback parameter
+bool readingOver = false;
+
+// callback function
+void callback(void *cbParam)
+{
+  *((bool *)cbParam) = true;
+}
+
+void setup() {
+  //Initialize serial and wait for port to open:
+  Serial.begin(9600);
+  while (!Serial) {
+    ; // wait for serial port to connect. Needed for native USB port only
+  }
+
+  Serial.println("-- analogReadDMA sketch --");
+  delay(500);
+
+  // Start DMA acquisiton
+  analogReadDMA(A0, samples, NB_SAMPLE, callback, &readingOver);
+}
+
+
+void loop() {
+  if (readingOver == true)
+  {
+    for (uint32_t idx=0; idx<NB_SAMPLE; idx++)
+    {
+      Serial.print("raw: ");
+      Serial.println(samples[idx], DEC);
+    }
+    readingOver = false;
+    analogReadDMA(A0, samples, NB_SAMPLE, callback, &readingOver);
+  }
+}