p igmon / Mbed 2 deprecated i2s_test_sample

Part of MicroGen4 Music Synthesizer Program. (But not test it yet.) I2S ,DMA ,Stereo ,16Bit Dac(PCM1781) See detail: http://www.geocities.jp/micro_diys/index2

Dependencies:   mbed

Now added generate Saw Wave to DAC function in generate(); You will hear Stereo saw wave sound now. /media/uploads/p_igmon/i2s_sample_test_audacity.png

more info: http://www.geocities.jp/micro_diys/i2s_test_sample/i2s_test_sample.html

Diff: Synthesizer.cpp

Revision:
1:48f506a7b488
Parent:
0:dc88722ab141
--- a/Synthesizer.cpp	Thu Jul 03 11:59:07 2014 +0000
+++ b/Synthesizer.cpp	Thu Sep 21 10:20:50 2017 +0000
@@ -9,23 +9,23 @@
 extern __IO BUFFER_StateTypeDef BufferOffset;
 
 void wave_generate(void){
-    U16 count;
-    S16 rch,lch;// 16bit stereo
-    volatile S16 *ptr0;
+    u16 count;
+    s16 rch,lch;// 16bit stereo
+    volatile s16 *ptr0;
 
-    if (BufferOffset == DMA_FullComplete){
-        ptr0 = (S16 *)&DMA_Buffer[DMA_BUFFERSIZE>>1];// From Half
+    if (bufferoffset == dma_fullcomplete){
+        ptr0 = (s16 *)&dma_buffer[dma_buffersize>>1];// from half
     }else{
-        ptr0 = (S16 *)&DMA_Buffer[0];// From Top
+        ptr0 = (s16 *)&dma_buffer[0];// from top
     }    
-    BufferOffset = DMA_Idle;
+    bufferoffset = dma_idle;
 
-    count = DMA_BUFFERSIZE/4;
+    count = dma_buffersize>>2;// 512samples
     while(count-- > 0){
 
         /* generate wave here */
-//      lch = .....
-//      rch = .....
+        lch = ((s16)(count - 256))<<6;// Saw Wave Lch
+        rch = ((s16)(256 -count))<<6;// Saw Wave Rch
         *ptr0++ = lch;
         *ptr0++ = rch;
      }