STM32 MP3 music player based on FatFs r0.14b & SD card (also a simple application of FatFs)

This article is not perfect ！！！

So far, it's just for learning notes , Please be careful when reading this article ！！

Write it at the front ：

FatFs Of I/O Interface operation has been written in the previous article , Now use it directly ！

The project mainly refers to the codes of wildfire and punctual atoms .

Said in the previous ： In fact, I don't like the code style of punctual atoms , Basically, they wrap their own function interfaces on the official library . Development projects are convenient , But it is not conducive to learning . Compared with wildfire, I like it very much , Its code is less modified in the official library or official routines , And the video lesson explains clear .

This article will be published in STM32F103 Elite Edition provides code routines based on , Understand its operation principle , And realize the function of music player based on the official library .

Inevitably, there will be code bug, This article just combs the programming ideas , Implementation process

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In the choice of chips , Both wildfire and punctual atoms are selected VS1053, This is quite consistent . The chip is a little expensive .

See other alternatives later , In short, when calling FatFs There should be little difference .

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VS1053

Although I don't want to use this chip , But the routine is there , I have to see it too .

This chip supports many strange formats ！

According to the official English manual ( In fact, I didn't quite understand ！)：

Supported audio decoding ：Ogg Vorbis, MP3, AAC, WMA and WAV PCM + ADPCM

In fact, I can't use so much , There is one MP3 That's it , There is no need to record .( I feel so superficial when I say so )

Communications

VS1053 adopt SPI Protocol to communicate with the host .48 Pins , I have to say so much .

VS1002 Local mode ( A new model )

🧐 The line to be connected

name	explain
XCS	Film selection input ( Low level active )
XDCS	Data slice selection / Byte synchronization
SCK	SPI Clock bus
SI	SPI Data input line
SO	SPI Data output line
DREQ	Data request
RST	Reset ( Low level active )

register

Unexpectedly 16 A register , Register pairs can be used VS1053 Control

come from [ The punctual atoms ]《MP3 Music module VS1503》

I won't elaborate on the functions of each register , Specific to see ：VS1053b Data manual

About VS1053 That's what I learned , Now let's read and write the file ！

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Implementation problems

Read the implementation code of wildfire , It doesn't feel good .

read MP3 File list

DIR dir;
u8 res;
FILINFO filinfo;
u8 *fn;    // Long filename 

res = f_opendir(&dir,"0:");    // Suppose the drive letter is 0
if(res == FR_OK)
{
    
    while(1)
    {    
        res = f_readdir(&dir,&filinfo);    // Read file information 
        if(res != FR_OK || filinfo.fname[0] == 0)    // I didn't read the file 
            break;
        fn = (u8 *)(* filinfo.fname)    // It is simpler to judge the file name here than before , I don't know 
        res = f_typetell(fn);    // Here you can determine the file type by yourself 
        if(res == MP3)    // Judge to be MP3 file type 
        {
              // It is judged here that MP3 File name for , You can store  
              // The list will be displayed soon after the storage  
        }

    }
}

Show

res = f_opendir(&dir,"0:/");
while(res == FR_OK)
{
    dir_sdi(&mp3dir,mp3indextbl[curindex]);    // Directory index function ？？？ This version is gone 
    res = r_readdir(&dir.&filinfo);    // Read the next file in the directory 
    if(res != FR_OK || filinfo.fname[0] == 0)
        break;    // At the end 
    fn = (u8 *)(* filinfo.fname);    // It is simpler to judge the file name here than before , I don't know 
    // This step can directly display fn 了 ！
    strcpy((char*)pname,"0:/");    
    strcat((char*)pname,(const char*)fn); 
    // Then play music 
    PlaySong(pname);   
}

Play

FIL* fmp3;
u8 *databuf;
u16 br;
u8 res,rval;	
u16 i=0;  

rval=0;	  
fmp3=(FIL*)mymalloc(SRAMIN,sizeof(FIL));// Application memory 
databuf=(u8*)mymalloc(SRAMIN,4096);		// open up 4096 Byte memory area 
if(databuf==NULL||fmp3==NULL)rval=0XFF ;// Memory request failed 
if(rval==0)
{
    	VS_Restart_Play();  					// Restart playback  
		VS_Set_All();        					// Set volume and other information  			 
		VS_Reset_DecodeTime();					// Reset decoding time  	
}
res = f_typetell(pname);
if(res == MP3)
{    
    VS_Load_Patch((u16*)vs1053b_patch,VS1053B_PATCHLEN); 
}
res=f_open(fmp3,(const TCHAR*)pname,FA_READ);    // Open file 	 
if(res == 0)
{
    VS_SPI_SpeedHigh();	// High speed 	
    while(rval == 0)
    {
        res = f_read(fmp3,databuf,4096,(UINT*)&br);// read out 4096 Bytes 
        i=0;
        do
        {    
            if(VS_Send_MusicData(databuf+i)==0)// to VS10XX Send audio data 
                i +=32;
            else
                mp3_msg_show(fmp3->fsize);// Show MP3 Information about 
        }while(i<4096);// Cycle to send 4096 Bytes  
        if(br!=4096||res!=0)    // Read it or make mistakes 
		{
			rval=0;
			break;// After reading the .		  
		} 
        f_close(fmp3);    // Close file 
    }
    else rval = 0xff;    // Something went wrong 
}
myfree(SRAMIN,databuf);	  	 		  	    
myfree(SRAMIN,fmp3);
return rval;

got it ！！！！ Understand the meaning ！！！

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I understand the implementation method ！

1️⃣ Define an array first or The linked list is used to store song names , Convenient access , It is also convenient to print playlists ！

2️⃣ Open Directory , Then read the directory entry ,f_readdir Items in the directory can be read in order ！ Then through the read object information , Judge its name . Four characters at the end of the foundation (.mp3) Judge whether it is MP3 file , If yes, it is stored in the song name sequence

3️⃣ By calling the song name sequence , Use f_open Open the file and use f_read Read file transfer decoding , In the transmission process, you can also judge whether there is the operation of the previous song and the next song . You can even select tracks to operate , Because there are song name sequences , It's also simpler .

In fact, most of them are VS1053 Chip related functions . Feel instantly transparent .

ok, Take a small step forward every day , Not impatient ！ come on.

Later, read and understand the code update ！