Adding comments related to troubleshooting low quality output with lots of static (#325)

Co-authored-by: Laurent Ellerbach <[email protected]>

Author: CoryCharlton

samples/I2S/Output/I2sWavPlayer.cs

@@ -1,4 +1,4 @@
-//
+//
 // Copyright (c) .NET Foundation and Contributors
 // See LICENSE file in the project root for full license information.
 //
@@ -16,7 +16,7 @@ namespace AudioPlayer
     /// You have to provide pin configuration for I2S communication and a full path to the
     /// WAV file you want to play.
     /// </summary>
-    public class I2sWavPlayer : IDisposable
+    public class I2SWavPlayer : IDisposable
     {
         public enum Bus
         {
@@ -28,15 +28,15 @@ public enum Bus
         private readonly FileStream _stream;
 
         /// <summary>
-        /// Creating a new instance of <see cref="I2sWavPlayer" />.
+        /// Creating a new instance of <see cref="I2SWavPlayer" />.
         /// </summary>
-        /// <param name="bus">The I2S bus ID on ESP32 plattforms.</param>
+        /// <param name="bus">The I2S bus ID on ESP32 platforms.</param>
         /// <param name="audioFile">Full path to WAV file.</param>
         /// <param name="bckPin">The Pin ID of the BCK pin. (32 for <see cref="Bus.One" />).</param>
         /// <param name="dataPin">The Pin ID of the Data Out pin. (33 for <see cref="Bus.One" />).</param>
         /// <param name="wsPin">The Pin ID of the WS pin. (25 for <see cref="Bus.One" />).</param>
         /// <exception cref="IOException">Throws an IOException if the WAV file provided does not have at least 44 bytes (header).</exception>
-        public I2sWavPlayer(Bus bus, string audioFile, int bckPin = 32, int dataPin = 33, int wsPin = 25)
+        public I2SWavPlayer(Bus bus, string audioFile, int bckPin = 32, int dataPin = 33, int wsPin = 25)
         {
             switch (bus)
             {
@@ -65,9 +65,10 @@ public I2sWavPlayer(Bus bus, string audioFile, int bckPin = 32, int dataPin = 33
 
             var headerParser = new WavFileHeader(header);
 
-            _i2S = new I2sDevice(new I2sConnectionSettings(1)
+            _i2S = new I2sDevice(new I2sConnectionSettings((int) bus)
             {
                 Mode = I2sMode.Master | I2sMode.Tx,
+                //Mode = I2sMode.Master | I2sMode.Tx | I2sMode.Pdm, // Try this if output contains lots of static and poor audio quality
                 CommunicationFormat = I2sCommunicationFormat.I2S,
 
                 SampleRate = headerParser.SampleRate,
@@ -127,7 +128,7 @@ private static I2sChannelFormat ToChannelFormat(short channels)
             {
                 1 => I2sChannelFormat.OnlyLeft,
                 2 => I2sChannelFormat.RightLeft,
-                _ => throw new ArgumentOutOfRangeException("channels", "Only supports either Mono or Stereo WAV files.")
+                _ => throw new ArgumentOutOfRangeException(nameof(channels), "Only supports either Mono or Stereo WAV files.")
             };
         }
 
@@ -139,9 +140,8 @@ private static I2sBitsPerSample ToBitsPerSample(short bitsPerSample)
                 16 => I2sBitsPerSample.Bit16,
                 24 => I2sBitsPerSample.Bit24,
                 32 => I2sBitsPerSample.Bit32,
-                _ => throw new ArgumentOutOfRangeException("bitsPerSample",
-                    "Only 8, 16, 24 or 32 bits per sample are supported.")
+                _ => throw new ArgumentOutOfRangeException(nameof(bitsPerSample), "Only 8, 16, 24 or 32 bits per sample are supported.")
             };
         }
     }
-}
+}

samples/I2S/Output/Program.cs

@@ -30,16 +30,19 @@
 }
 
 // SD Card:
-uint cs = 5;
+const uint cs = 5;
 Configuration.SetPinFunction(23, DeviceFunction.SPI1_MOSI);
 Configuration.SetPinFunction(18, DeviceFunction.SPI1_CLOCK);
 Configuration.SetPinFunction(19, DeviceFunction.SPI1_MISO);
 
 var sdCard = new SDCard(new SDCard.SDCardSpiParameters { spiBus = 1, chipSelectPin = cs });
 sdCard.Mount();
 
-var audioFile = "D:\\Variation-CLJ013901.wav";
-var player = new I2sWavPlayer(I2sWavPlayer.Bus.One, audioFile);
+// NOTE: If the audio has low quality and lots of static you may need to update
+// I2sWavPlayer to add the I2sMode.Pdm flag when configuring I2sConnectionSettings
+
+const string audioFile = "D:\\Variation-CLJ013901.wav";
+var player = new I2SWavPlayer(I2SWavPlayer.Bus.One, audioFile);
 player.Play();
 player.Dispose();