Diff: TestAudio.cpp

Revision:

7:48375cb50f3a

Parent:

6:4d97917c7dea

--- a/TestAudio.cpp	Tue Sep 09 14:20:12 2014 +0000
+++ b/TestAudio.cpp	Thu Sep 25 07:17:44 2014 +0000
@@ -157,7 +157,7 @@
     _i2sTx.masterslave(I2S_SLAVE);
     _i2sTx.start();
 
-    
+    int lastVol = -1000; // value not important
     do
     {
         //check if joystick-down pressed = play wave-file
@@ -184,7 +184,15 @@
             _codec.input_mute(false);
         }
 
-        _codec.headphone_volume(_aIn);
+        //attempt to filter out the small variations in analog values and
+        //only update volume when a "large enough" change is detected.
+        float v = _aIn;
+        int val = ((int)(v*1000))>>2;
+        if (val != lastVol) {
+            _codec.headphone_volume(v);
+            lastVol = val;
+        }
+        //_codec.headphone_volume(_aIn);
         wait(0.25);
     } while (up.read() != 0);