analog signal i2s

Writing software for systems that use VLSI Solution's devices as slave codecs to a host microcontroller.
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evsandron@gmail.com
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analog signal i2s

Post by evsandron@gmail.com » Sun 2019-12-08 12:26

Good day, I'm using google translator. please help me. when I turn on i2s vs1053, I have no data in it; instead, there is an analog signal with interference. I make the inclusion as follows
vs1053_writeCommand (vs1053_WRAMADDR, 0xc017);
vs1053_writeCommand (vs1053_WRAM, 0xf0);
vs1053_writeCommand (vs1053_WRAMADDR, 0xc040);
vs1053_writeCommand (vs1053_WRAM, 0x0c);

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pasi
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Re: analog signal i2s

Post by pasi » Mon 2019-12-09 13:59

Are you able to correctly play files using the analog output?

The I2S output is carrying the same signal as the analog outputs, so if you have problems with the analog output, you have to sort that out first.

Note that the I2S should be configured after normal configuration, and you should use the cancel procedure to end playing each file. If you give a software reset, you need to reconfigure I2S.

Also make sure your SCI register read and write operations are working correctly.
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Re: analog signal i2s

Post by evsandron@gmail.com » Tue 2019-12-10 23:05

thanks for the answer, yes I can play normally on the analog output. could you describe in detail exactly how to configure i2s besides enabling

Hannu
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Re: analog signal i2s

Post by Hannu » Wed 2019-12-11 10:46

Few things to test:
Just to make sure your SCI interface is working, try to adjust volume through it in normal decoding mode. If it works, SCI works.

Also does your device have 12.288 MHz clock? If it is based on our reference designs, it should have it.

There is not much to configure i2s as shown in VS1053 datasheet. The first write sets data direction to output and the last 0x0c data is to enable MCLK output, enables I2S out at 48 kHz sample rate. 0x0d would be 96 kHz and 0x0e would set to 192 kHz. After that everything sent to DAC is copied to digital i2s output.

Where do you have the noise you are referring? In external DAC's output or in digital i2s signals on oscilloscope's screen?
if the noise is in analog output of the external DAC, check that it supports 16-bit i2s samples.

If the analog noise in the digital i2s signals, then I would suspect you have problem with you PCB.

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Re: analog signal i2s

Post by evsandron@gmail.com » Wed 2019-12-11 21:06

Hannu wrote:
Wed 2019-12-11 10:46
Few things to test:
Just to make sure your SCI interface is working, try to adjust volume through it in normal decoding mode. If it works, SCI works.

Also does your device have 12.288 MHz clock? If it is based on our reference designs, it should have it.

There is not much to configure i2s as shown in VS1053 datasheet. The first write sets data direction to output and the last 0x0c data is to enable MCLK output, enables I2S out at 48 kHz sample rate. 0x0d would be 96 kHz and 0x0e would set to 192 kHz. After that everything sent to DAC is copied to digital i2s output.

Where do you have the noise you are referring? In external DAC's output or in digital i2s signals on oscilloscope's screen?
if the noise is in analog output of the external DAC, check that it supports 16-bit i2s samples.

If the analog noise in the digital i2s signals, then I would suspect you have problem with you PCB.
Thank you for your attention and answers. analog noise on my vs1053 i2s pins; I see an analog signal on the oscilloscope. I attached a screen shot of the board. I used 2 different boards different and there is one and the same problem. I can adjust the bass sound. I can’t figure out what I'm doing wrong. I suspect that at the i2s output a digital signal and an analog are superimposed on each other, but my oscilloscope does not allow me to see this. the same waveform output channel clock i2s does not look as it should.
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pasi
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Re: analog signal i2s

Post by pasi » Thu 2019-12-12 15:09

Do you have the grounds (AGND and GND) connected below the IC with a trace (R24 is a trace, not an actual resistor)?

You have 10kOhm pull-downs on all of the the I2S output pins. Have you tried removing them?
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Re: analog signal i2s

Post by evsandron@gmail.com » Sat 2019-12-14 20:42

pasi wrote:
Thu 2019-12-12 15:09
Do you have the grounds (AGND and GND) connected below the IC with a trace (R24 is a trace, not an actual resistor)?

You have 10kOhm pull-downs on all of the the I2S output pins. Have you tried removing them?

Good afternoon, it worked, I disconnected the analog part of vs1053 from the power supply, it turned off the analog noise at the outputs I2S LROUT, I2S MCLK, I2S SCLK. But somehow there is analog noise at the output of i2s_data, this does not interfere with the operation of the DAC, it samples without interference. DAC model pcm5102

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Re: analog signal i2s

Post by pasi » Mon 2019-12-16 16:22

You seem to power IOVDD, AVDD, and SD card from the same 3V3.

Your 3V3 power supply may be insufficient, for example SD cards take really big peak currents and would then affect both AVDD and IOVDD, seen in the IO pins. (We use a separate regulator for SD card with vs1000/vs1005/vs1010, because their on-board regulators cannot handle the current draw.)

How is the external DAC powered?
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Re: analog signal i2s

Post by evsandron@gmail.com » Mon 2019-12-16 21:46

pasi wrote:
Mon 2019-12-16 16:22
You seem to power IOVDD, AVDD, and SD card from the same 3V3.

Your 3V3 power supply may be insufficient, for example SD cards take really big peak currents and would then affect both AVDD and IOVDD, seen in the IO pins. (We use a separate regulator for SD card with vs1000/vs1005/vs1010, because their on-board regulators cannot handle the current draw.)

How is the external DAC powered?
Good day, I do not use sd card music I play with spi flash using the stm32f1 microcontroller. The external DAC is powered by stm32. please answer whether vs1053 can play dsd format. I am satisfied with such a solution with the analog part turned off, it does not cause interference during playback and does not affect the quality of the clock lines

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pasi
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Re: analog signal i2s

Post by pasi » Tue 2019-12-17 16:35

evsandron@gmail.com wrote:
Mon 2019-12-16 21:46
I am satisfied with such a solution with the analog part turned off, it does not cause interference during playback and does not affect the quality of the clock lines
My only concern is that there may be hidden issues in your design, and from experience those can come back to bite you later.
evsandron@gmail.com wrote:
Mon 2019-12-16 21:46
whether vs1053 can play dsd format.
There is a DSD64 decoder in the vs1053b patches package ( http://www.vlsi.fi/en/support/software/ ... tches.html ), but I don't really have a good setup for testing it. Let me know whether you can get it to work.
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