LUTS.cpp

00001 #include "mbed.h"
00002 #include "LUTs.h"
00003 
00004 LUTs::LUTs()
00005 {
00006 }
00007 LUTs::~LUTs()
00008 {
00009 }
00010 volatile uint16_t sin_wavtable[1024];
00011 volatile uint16_t tri_wavtable[1024];
00012 volatile uint16_t pulse_wavtable[1024];
00013 
00014 void LUTs::initial_wavetables()
00015 {
00016     sin_wavetable();
00017     tri_wavetable(50);
00018     pulse_wavetable(50);
00019 }
00020 
00021 void LUTs::sin_wavetable()
00022 {
00023     //printf("Generating sin Wavetable \n");
00024     for (int i=0; i<1024; i++) { //Size of table
00025         sin_d= 65535*(0.5*sin(2.0*PI*(i/1024.0))+0.5); //Genrate Value
00026         rem= fmod(sin_d,1); //calculates remainder for rounding
00027         //printf("preround= %g -", sin_d); //DEBUG
00028         if (rem>=0.5) {
00029             sin_d=ceil(sin_d); //round UP
00030         } else {
00031             sin_d= floor(sin_d-rem); //round DOWN
00032         }
00033         // printf("Postround= %g -",sin_d); //DEBUG
00034         sin_u=((uint16_t)sin_d); //Value converted to unsigned
00035         //printf("sin_u= %u \n", sin_u);
00036         sin_wavtable[i]=sin_u;//Sets in Global Variable
00037         //sin_wavtable[i]=get_sin(i);
00038     }
00039     #ifdef SLOW_TIME
00040     for (int i=0; i<1024; i=i+128) {
00041     printf("sin_wav[%d]= %u \n", i, sin_wavtable); //prints Key values
00042     } 
00043     #endif
00044 }
00045 
00046 void LUTs::tri_wavetable(int pulsewidth)
00047 {
00048     //printf("Generating Tri-wavetable\n");
00049     tri_wavtable[0]=0; //sets 0 value
00050     rise_t=(pulsewidth*1024/100); //Calculates rise samples
00051     rise_tu=(uint16_t)rise_t;
00052     fall_tu=1024-rise_tu; //Calculates fall samples
00053     dif=65536/rise_t; //Calculates Rise Dif
00054     dif_u=(uint16_t)dif; //converts to uint
00055     
00056     #ifdef SLOW_TIME //Prints Values in SLOW_TIME case
00057     printf("PRINTING TRI WAVETABLE Values\n");
00058     printf("PW= %d \n",pulsewidth);
00059     printf("Rise Samples= %u\n", rise_tu);
00060     printf("Fall Samples= %u\n", fall_tu);
00061     printf("UP sample dif= %u\n", dif_u);
00062     #endif   
00063     for (int i=1; i<=rise_tu; i++) { //Generates Rise Points
00064         tri_wavtable[i]=tri_wavtable[i-1]+dif_u;
00065     }
00066     dif=65536/fall_tu; //Calcualtes Fall Diff
00067     dif_u=(uint16_t)dif;
00068     
00069     #ifdef SLOW_TIME
00070     printf("down sample dif= %u\n", dif_u);
00071     #endif  
00072     for (int i=rise_tu; i<1024; i++) { //Generates Fall Points
00073         tri_wavtable[i]=65535-((i-rise_tu)*dif_u);
00074     }
00075     #ifdef SLOW_TIME
00076     tri_wav_results();//Prints Key Results
00077     #endif
00078 }
00079 
00080 
00081 void LUTs::pulse_wavetable(int pulsewidth)
00082 {
00083     //printf("Generating Pulse-wavetable\n");
00084     up_t=(pulsewidth*1024/100); //Samples Up
00085     up_tu=(uint16_t)up_t;
00086     for (int i=0; i<=up_tu; i++) { //Until Down
00087         pulse_wavtable[i]=58981; //Headroom to normalise Volume
00088         //printf("up itt = %d\n",i);
00089     }
00090 
00091     for (int i=up_tu+1; i<1024; i++) { //Until Over
00092         pulse_wavtable[i]=6553; //HEadroom Included
00093         //printf("down itt = %d\n",i);
00094     }
00095 }
00096 
00097 void LUTs::tri_wav_results() { //Prints Results
00098     printf("TRI_WAV_RESULTS:\n");
00099     printf("i,out\n");
00100     for (i=0; i<=1024; i=i+64) {
00101         printf("%d, %u\n",i,tri_wavtable[i]);
00102         }
00103     }