main.cpp

00001 #include "mbed.h"
00002 #include "sinelookup.h"
00003 #include "TLV320.h"
00004 #include "I2S.h"
00005 
00006 #define SAMPLERATE 48000
00007 
00008 
00009 TLV320 codec(p9, p10);
00010 I2S i2s(I2S_TRANSMIT, p5, p6, p7);
00011 
00012 AnalogIn aIn(p19);
00013 AnalogIn vol(p20);
00014 
00015 float phase_l;
00016 float phase_r;
00017 int minibuf[16];
00018 float skipper;
00019 float volume;
00020 float phase_kill;
00021 
00022 
00023 extern "C" void HardFault_Handler()
00024 {
00025     error("Hard Fault!\n");
00026 }
00027 
00028 
00029 void play(void)
00030 {   
00031     int to_write = i2s.max_fifo_points() - (i2s.fifo_points());
00032     for(int i = 0; i < to_write; i+=2) {
00033         minibuf[i] = int(float(sine16lookup[int(phase_l)])*volume);
00034         //minibuf[i] = int(sine16lookup[int(phase_l)]);
00035         minibuf[i+1] = int(float(sine16lookup[int(phase_r)])*volume);
00036         phase_l+=skipper;
00037         phase_r = phase_l + phase_kill;
00038         while(phase_l >= SINE16LENGTH) {
00039             phase_l -= SINE16LENGTH;
00040         }
00041         
00042         while(phase_r >= SINE16LENGTH) {
00043             phase_r -= SINE16LENGTH;
00044         }
00045         while(phase_r< 0) phase_r += SINE16LENGTH;
00046     }
00047     i2s.write(minibuf, to_write);
00048 }
00049 
00050 /* main */
00051 int main()
00052 {
00053     skipper = (aIn*49)+1;
00054     
00055     codec.power(true);
00056     codec.frequency(SAMPLERATE);
00057     codec.wordsize(16);  
00058     codec.master(false);
00059     codec.headphone_volume(0.5);
00060     codec.start();
00061     
00062     i2s.frequency(SAMPLERATE);
00063     i2s.wordsize(16);
00064     i2s.stereomono(I2S_STEREO);
00065     i2s.masterslave(I2S_MASTER);
00066     i2s.attach(&play);
00067     i2s.start();
00068     
00069     while(1)
00070     {
00071         skipper = (aIn*30)+1;
00072 
00073         volume = 1;
00074         phase_kill = (vol-0.5)*400;
00075 
00076         //printf("Skipper:%f, %i, %i\n\r",skipper, to_write,i2s.fifo_level());
00077         
00078         /*if(flag)
00079         {
00080         printf(".");
00081         flag = false;
00082         }*/
00083     }
00084 
00085 }