VS1003

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[moved from Off Topic to GE]
hi everyone

i have a problem using VS1003 , i have connected the typical connection suggested by VLSI solution (VS1003 datasheet) i use a 3.3 regulator and a diode for the IOVDD and CVDD power lines , it must be about 2.6 V , which would be appropriate for that voltage , but to be simple it doesn't work

i've checked the connections twice and it i am sure that there's no mistake , i read the MP3 file on my computer and send it to my MC ATMEGA32L via RS232 and send the read bytes to VS1003 , there's no prblem in reading the MP3 file i've tested it .

i tried to send SCI commands but sometimes DREQ line was always down , and sometimes usually after several reserts it was high but the received SPI bytes was not correct . because fro example i wrote to a register and then i read it , the read byte wasn't the written byte .

i tried to send SDI via recieved bytes from RS232 but there was nothing able to here on output. it wasn't any noise neither , VS1003 really seems to be dead ... !!

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bias your soul to enjoy ..

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If you cant get SCI to work, you'll never succeed with SDI. If SCI is not funtioning (and DREQ is not acting right, you have a HW issue).
Make sure you send all signals as specified in the DS, the chip is sensitive to the right sequence.

Sending MP3 data via RS232 wont work unless you have a very high speed link. The chip expect the initial buffer fill (about 16kbits, iirc) at about 1Mbps. You can NOT just send data at the same rate as the actual MP3 stream.
Signals like DREQ and BSYNC, MUST be handled correctly.

/Jesper
http://www.yampp.com
The quick black AVR jumped over the lazy PIC.
What boots up, must come down.

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Who says MP3 data can't be 64kbps which should work great over 115200bps RS232 link?

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As I mentioned - the chip need an initial buffer fill.

/Jesper
http://www.yampp.com
The quick black AVR jumped over the lazy PIC.
What boots up, must come down.

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sorry for the late ...
i checked the signal and finally i could send SCI commands correctly ..

the problem was ..:

sometimes (half of times!!) when i turn the circuit on , it doesn't start and it waits for DREQ to be set . when i try to turn it on and off again and again suddenly it starts to work then when i check the registers of VS1003 ,it's written correctly .

yes you are right . RS232 is not fast enough to send MP3 streams , so i wrote a program reading the mp3 file and make a code like this :

VS_d_write(0xF8);
VS_d_write(0x91);
VS_d_write(0xB2);
VS_d_write(0x6A);
VS_d_write(0x35);
VS_d_write(0xF7);
VS_d_write(0xA9);
VS_d_write(0x01);
VS_d_write(0xFF);
VS_d_write(0xE2);
VS_d_write(0x12);
VS_d_write(0xC0);
VS_d_write(0x7A);
VS_d_write(0xDE);
VS_d_write(0xEF);
VS_d_write(0xA1);
VS_d_write(0x3A);
VS_d_write(0xB8);
VS_d_write(0xF6);
VS_d_write(0x08); 

so Mp3 streams will be save on MC's flash . this is the first section before driving SD card and if tests was successful it will be upgraded to SD card, and SPI speed is sufficient for reading mp3 files ..

Anyway .. do you have any idea about my problem ? that suddenly at start the VS decides not to work and when i wait nothing happens ? the DREQ would be always on . but when i turn off and on the circuit again and again suddenly it starts to work ... ?

bias your soul to enjoy ..