Added example TestFFT1024.ino

examples/TestFFT1024/TestFFT1024.ino

@@ -0,0 +1,94 @@
+// TestFFT1024.ino       Bob Larkin  W7PUA
+// Started from PJRC Teensy  Examples/Audio/Analysis/FFT
+//
+// Compute a 1024 point Fast Fourier Transform (spectrum analysis)
+// on audio connected to the Left Line-In pin.  By changing code,
+// a synthetic sine wave can be input instead.
+//
+// The first 40 (of 512) frequency analysis bins are printed to
+// the Arduino Serial Monitor.
+//
+// T4.0: Uses 6.1% processor and 9 F32 memory blocks, both max.
+//
+// This example code is in the public domain.
+
+#include <Audio.h>
+#include "OpenAudio_ArduinoLibrary.h"
+
+const int myInput = AUDIO_INPUT_LINEIN;
+//const int myInput = AUDIO_INPUT_MIC;
+
+// Create the Audio components.  These should be created in the
+// order data flows, inputs/sources -> processing -> outputs
+//
+// AudioInputI2S_F32          audioInput;  // audio shield: mic or line-in
+AudioSynthSineCosine_F32   sinewave;
+AudioAnalyzeFFT1024_F32    myFFT;
+AudioOutputI2S_F32         audioOutput; // audio shield: headphones & line-out NU
+
+// Connect either the live input or synthesized sine wave
+// AudioConnection_F32        patchCord1(audioInput, 0, myFFT, 0);
+AudioConnection_F32        patchCord1(sinewave, 0, myFFT, 0);
+
+AudioControlSGTL5000 audioShield;
+
+uint32_t count = 0;
+
+void setup() {
+  Serial.begin(300); // Any speed works
+  delay(1000);
+
+  AudioMemory_F32(20);
+
+  // Enable the audio shield and set the output volume.
+  audioShield.enable();
+  audioShield.inputSelect(myInput);
+  audioShield.volume(0.5);
+
+  // Set windowing function
+  // myFFT.windowFunction(NULL);
+  // myFFT.windowFunction(AudioWindowNone);  // Same as NULL
+  // myFFT.windowFunction(AudioWindowHanning1024);  // default
+  // The next Kaiser window needs a dB peak sidelobe number
+  myFFT.windowFunction(AudioWindowKaiser1024, 70.0f);
+  // myFFT.windowFunction(AudioWindowBlackmanHarris1024);
+
+  // To print the window function:
+  // float* pw=myFFT.getWindow();
+  // for(int jj=0; jj<1024; jj++)
+  //    Serial.println(*pw++, 6);
+
+  // Create a synthetic sine wave, for testing
+  // To use this, edit the connections above
+  sinewave.frequency(1034.0);   // Bin 24
+  // sinewave.frequency(1055.0f);  // Bin 24.5, demonstrates windowing
+
+  myFFT.setOutputType(FFT_DBFS);  // FFT_RMS or FFT_POWER or FFT_DBFS
+}
+
+void loop() {
+  if (myFFT.available()) {
+    // each time new FFT data is available
+    // print it all to the Arduino Serial Monitor
+    Serial.print("FFT: ");
+    for (int i=0; i<40; i++) {
+        Serial.print(myFFT.read(i), 2);
+        Serial.print(",");
+    }
+    Serial.println();
+  }
+  
+/* if(count++ == 3000) {
+     Serial.print("CPU: Percent Usage, Max: ");
+     Serial.print(AudioProcessorUsage());
+     Serial.print(", ");
+     Serial.println(AudioProcessorUsageMax());
+     Serial.print("   Float 32 Memory: ");
+     Serial.print(AudioMemoryUsage_F32());
+     Serial.print(", ");
+     Serial.println(AudioMemoryUsageMax_F32());
+     }
+  delay(2);
+ */
+}
+