main.cpp

00001 #include "mbed.h"
00002 #include "string.h"
00003 #include "stdio.h"
00004 #include "math.h"
00005 #include "C12832.h"
00006 #include "SDHCFileSystem.h"
00007 #include "_bitio.h"
00008 #include <string>
00009 using namespace std;
00010 
00011 //Communication\interfaces
00012 Serial pc(USBTX,USBRX); //USB serial
00013 C12832 lcd(p5, p7, p6, p8, p9); //LCD
00014 DigitalIn RW(p10);
00015 SDFileSystem sd(p11, p12, p13, p15, "sd"); //SDCard
00016 DigitalIn sdDetect(p14); //CardDetect
00017 
00018 //in- and outputs
00019 DigitalIn PauseBtn(p19);
00020 DigitalIn StopBtn(p20);
00021 DigitalIn UpBtn(p18);
00022 DigitalIn DownBtn(p17);
00023 
00024 DigitalOut led1(LED1);
00025 DigitalOut led2(LED2);
00026 
00027 
00028 //DAC output
00029 // BU9480F define
00030 //SPI bu9480f(p23,p24,p21);
00031 //DigitalOut LRCLK(p22);
00032 // BU9480F define.end
00033 
00034 //ticker- sampling
00035 Ticker tick;
00036 
00037 //timer
00038 Timer dur;
00039 
00040 //func
00041 void read_file_names(char *dir); //SDCard read file names
00042 void menu();
00043 void PlaySong(int m);
00044 void StopSong();
00045 void dac_out();
00046 void encode(long int n);
00047 void decode(void);
00048 
00049 //variables
00050 int m = 1; //index of choosen songs
00051 int i = 0; //index of files from folder
00052 int Paused = 0;//Is the song paused?
00053 int Stopped = 0; //Is the song stopped?
00054 char* songs[5];
00055 
00056 // a FIFO for the DAC
00057 #define TXFIFO_FULL 1
00058 #define RAM_LENGTH 8192//8192
00059 #define RAM_LIMIT (RAM_LENGTH - 1)
00060 volatile short DAC_fifo[RAM_LENGTH];
00061 volatile short DAC_wptr=0;
00062 volatile short DAC_rptr=0;
00063 volatile short DAC_on;
00064 volatile short DAC_diff=0;
00065 
00066 int main()
00067 {
00068     while(sdDetect == 0) {
00069         lcd.printf("Insert SD Card!");
00070         wait(0.5);
00071     }
00072     pc.printf("going out of main");
00073     menu();
00074 }
00075 
00076 void menu()
00077 {
00078     lcd.cls();
00079     sd.disk_initialize();
00080     read_file_names("/sd/Music");
00081     while(1) {
00082         lcd.cls();
00083         lcd.printf("Please select a song");
00084         if(UpBtn == 1) {
00085             m++;
00086             if(m == 5) {
00087                 m = 0;
00088             }
00089         } else if(DownBtn == 1) {
00090             m--;
00091             if(m == -1) {
00092                 m = 4;
00093             }
00094         }
00095         lcd.locate(0,15);
00096         lcd.printf("%s", (songs[m]));
00097         if(PauseBtn == 1) {
00098             pc.printf("going to play song");
00099             PlaySong(m);
00100         }
00101         wait(0.1);
00102     }
00103 }
00104 
00105 void read_file_names(char *dir) // function that reads in file names from sd cards
00106 {
00107     pc.printf("found files");
00108     DIR *dp;
00109     struct dirent *dirp;
00110     dp = opendir(dir);
00111     //read all directory and file names in current directory into filename vector
00112     while((dirp = readdir(dp)) != NULL) {
00113         songs[i] = dirp->d_name;
00114         i++;
00115     }
00116 }
00117 
00118 void PlaySong(int m)
00119 {
00120     string songname = songs[m];
00121     string a = "/sd/Music/";
00122     string fname = a + songname; //retrieves the file name
00123     FILE *infp;
00124     dur.start();
00125     lcd.cls();
00126     lcd.locate(0,0);
00127     lcd.printf("Now playing");
00128     infp = fopen(fname.c_str(),"rb"); //opens the music file
00129     // bu9480f init
00130     //bu9480f.format(16,0);
00131     //bu9480f.frequency(16000000); //16MHz
00132     // bu9480f init.end
00133     tick.attach_us(&dac_out, 41); //set 24.4kHz sampling data
00134     decode();
00135     //plays the music file
00136 
00137     tick.detach();
00138     fclose( infp );
00139     menu();
00140 }
00141 
00142 void StopSong()
00143 {
00144     pc.printf("stopped");
00145     lcd.cls();
00146     dur.reset();
00147     tick.detach();
00148     menu();
00149 }
00150 
00151 void dac_out()
00152 {
00153     pc.printf("playing");
00154     if(StopBtn == 1) {
00155         StopSong();
00156     }
00157     if(PauseBtn == 1) {
00158         dur.stop();
00159         if(Paused == 1) {
00160             Paused = 0;
00161             dur.start();
00162         } else {
00163         Paused = 1;
00164         }
00165     }
00166     if(Paused == 0) {
00167         lcd.locate(0,10);
00168         lcd.printf("%s", (songs[m]));
00169         //  printf("\t%d\r\n",DAC_diff);
00170         if (DAC_diff > 1) {
00171             led2 = 0;
00172 
00173             //LRCLK = 0;
00174             //bu9480f.write(DAC_fifo[DAC_rptr++]);
00175             DAC_rptr &= RAM_LIMIT;
00176 
00177             //LRCLK = 1;
00178             //bu9480f.write(DAC_fifo[DAC_rptr++]);
00179             DAC_rptr &= RAM_LIMIT;
00180 
00181             DAC_diff-=2;
00182 
00183         } else led2 = 1;
00184         lcd.locate(0,20);
00185         lcd.printf("%2.f s", dur.read());
00186     } else {
00187         lcd.printf("PAUSED");
00188     }
00189 }
00190 
00191 void encode(long int n)
00192 {
00193     pc.printf("encoding");
00194     int zero_shift = 0;
00195 
00196     if(n < 0) {
00197         putbit(0);                    // sign (put 0:if n as negative)
00198         n = -n;                        // n = abs(n)
00199         //printf("\t 0");
00200     } else {
00201         putbit(1);                    // sign (put 1:if n as positive)
00202         //printf("\t 1");
00203     }
00204     zero_shift = (n >> (k));
00205     //printf("\t shift= %d",zero_shift);
00206     while(zero_shift > 0) {
00207 
00208         zero_shift--;
00209         putbit(0);
00210     }    // put n/(2^k) 0's
00211 
00212     putbit(1);                        // terminating "1"
00213     putbits(k,rightbits(k,n));
00214     //printf("\t finish= %d \r\n",(n & ((1U<<k)-1)));
00215 }
00216 
00217 
00218 
00219 void decode(void)
00220 {
00221     pc.printf("decoding");
00222     //short dac_data;
00223     long int decode_buff;
00224     short diff,diff2;
00225     unsigned int buff_sign,zero_shift;
00226     //char flag;
00227 
00228     diff = 0;
00229     diff2 = 0;
00230     // get sign(1 for positive, 0 for negative)
00231     while(1) {
00232 
00233         if((buff_sign = getbit())==OVERRUN)break;
00234         zero_shift = 0;
00235         while(getbit()==0)zero_shift++;
00236 
00237         decode_buff = (signed int)((1U << k)*zero_shift);
00238         decode_buff += (getbits(k));
00239 
00240         if(!buff_sign)decode_buff =- decode_buff;
00241         /* return decode_buff; */
00242         diff =(diff + decode_buff);
00243         DAC_fifo[DAC_wptr++]=(short)diff;
00244         DAC_wptr &= RAM_LIMIT;
00245         //DAC_diff++;
00246         while (DAC_diff > RAM_LIMIT) {
00247             led1 = 1;
00248         }   //wait
00249         led1=0;
00250 
00251         if((buff_sign = getbit())==OVERRUN)break;
00252         zero_shift = 0;
00253         while(getbit()==0)zero_shift++;
00254 
00255         decode_buff = (signed int)((1U << k)*zero_shift);
00256         decode_buff += (getbits(k));
00257 
00258         if(!buff_sign)decode_buff =- decode_buff;
00259         /* return decode_buff; */
00260         diff2 =(diff2 + decode_buff);
00261 
00262         DAC_fifo[DAC_wptr++]=(short)diff2;
00263         DAC_wptr &= RAM_LIMIT;
00264         DAC_diff+=2;
00265 
00266         while (DAC_diff > RAM_LIMIT) {
00267             led1 = 1;
00268         }   //wait
00269         led1=0;
00270 
00271 
00272 
00273     }
00274 }