add example code

examples/NoiseGate/main.cpp

@@ -0,0 +1,60 @@
+#include <Audio.h>
+// the next line can be skipped if more perfomance is needed
+#define NOISEGATE_EXTENDEDINFO
+#include <OpenAudio_ArduinoLibrary.h>
+#include <Arduino.h>
+
+AudioInputI2S_F32 i2sAudioIn1;
+AudioOutputI2S_F32 i2sAudioOut1;
+AudioEffectNoiseGate_F32 noiseGate;
+
+AudioConnection_F32 patchCordL1(i2sAudioIn1, 0, noiseGate, 0);
+AudioConnection_F32 patchCordL2(noiseGate, 0, i2sAudioOut1, 0);
+AudioConnection_F32 patchCordR1(i2sAudioIn1, 1, i2sAudioOut1, 1);
+
+
+
+#define LED_RED 0
+#define LED_YELLOW 1
+#define LED_GREEN 2
+
+//The setup function is called once when the system starts up
+void setup(void)
+{
+  //Start the USB serial link (to enable debugging)
+  Serial.begin(115200);
+  delay(500);
+  Serial.println("Setup starting...");
+
+  //Allocate dynamically shuffled memory for the audio subsystem
+  AudioMemory(20);
+  AudioMemory_F32(20);
+ 
+  //Put your own setup code here
+  pinMode(LED_RED, OUTPUT);
+  pinMode(LED_GREEN, OUTPUT);
+  pinMode(LED_YELLOW, OUTPUT);
+
+  // setup the noise gate. it is probaly a good idea to filter the incoming signal @20 Hz, maybe this colud be added in the future
+  noiseGate.setOpeningTime(0.02f);
+  noiseGate.setClosingTime(0.05f);
+  noiseGate.setHoldTime(0.1);
+  noiseGate.setThreshold(-40);
+
+  //End of setup
+  Serial.println("Setup complete.");
+};
+
+//After setup(), the loop function loops forever.
+//Note that the audio modules are called in the background.
+//They do not need to be serviced by the loop() function.
+float lastVal = 0;
+void loop(void)
+{
+
+  bool thresTrigger = noiseGate.infoIsOpen();
+  digitalWrite(LED_RED, !thresTrigger);
+  digitalWrite(LED_GREEN, thresTrigger);
+  digitalWrite(LED_YELLOW, noiseGate.infoIsOpeningOrClosing());
+  
+};