TLV320AIC3204: music level detect without minidsp

Zhou JianQiang

Prodigy 80 points

Part Number: TLV320AIC3204

Tool/software:

We want to design a portable music player which have RGB led and can breath with music level.

We want to know whether TLV320AIC3204 can support muisc level detection?

If not, which similar device can do this? And how to do?

1 month ago

0 Jeff McPherson 1 month ago

TI__Mastermind 31605 points

Hi Zhou,

There's not a way to directly do this with the AIC3204 or any of our audio codecs.

What you're describing is called a "VU Meter" by audio professionals. I recommend you search for VU meter circuit designs. A simple approach would be to use a full bridge rectifier on the output with a smoothing capacitor to turn the audio signal into an approximate DC power signal equivalent. You can then use this to drive an LED.

Best regards,
Jeff McPherson

0 Zhou JianQiang 1 month ago in reply to Jeff McPherson

Prodigy 80 points

Hi Jeff McPherson :

I think I can read music level from DAC by i2c, then control LED by code, in this case, I don't need VU meter circuit designs.

Does AIC3204 or other DAC can detect music level? I prefer to read the level of the input, not from speaker.

0 Jeff McPherson 1 month ago in reply to Zhou JianQiang

TI__Mastermind 31605 points

Hi Zhou,

If you want to correlate the LED brightness, to DAC volume setting then you can read I2C to determine this. But the LED will remain a constant brightness. It will not react dynamically to the music being played. Loud music and soft music will cause the same brightness since the DAC volume setting remains the same. If that's okay then this works. If you want the LED to react in real time to the music level then you need a VU type design.

Best regards,
Jeff McPherson

0 Zhou JianQiang 1 month ago in reply to Jeff McPherson

Prodigy 80 points

Hi Jeff McPherson :

Can you explain the details about these modules in PPS?

Do you mean I can't use these modules to detect music level?

0 Jeff McPherson 29 days ago in reply to Zhou JianQiang

TI__Mastermind 31605 points

Hi Zhou,

Those blocks do not provide any register reporting. They are meant only to be used with other blocks as part of a larger algorithm. If you right click on those blocks and select "Help" it will pull up a page giving details on those blocks. The output value can be used with other blocks but you can not directly obtain those values.

Best regards,
Jeff McPherson

0 Zhou JianQiang 28 days ago in reply to Jeff McPherson

Prodigy 80 points

Hi Jeff McPherson

I am sorry, but I still don't understand, I read you reply in below question:

https://e2e.ti.com/support/audio-group/audio/f/audio-forum/1368510/tlv320aic3254evm-k-tlv320aic3254?tisearch=e2e-sitesearch&keymatch=TLV320AIC3254%25252520music%25252520level

Isn't that one way to get the level of the music?

+1 Jeff McPherson 27 days ago in reply to Zhou JianQiang

TI__Mastermind 31605 points

Hi Zhou,

Sorry I misspoke on my previous post. They don't have a direct register attached to them, but you can obtain the information directly from the DSP coefficients. That is a good way to more accurately obtain the instantaneous output level, but it still requires I2C to access. If you have a host that can obtain this data quickly and regularly, you might be able to use that to drive an LED.

Best regards,
Jeff McPherson

0 Zhou JianQiang 27 days ago in reply to Jeff McPherson

Prodigy 80 points

Hi Jeff McPherson

Yes, I have a host, so I think it is OK.

But I don't understand the formula provided in help page.

As far as I know, the max of digital signal is 0dBFs, when input is 0dBFs, what is the result of level detector?

How do I know the result for any dBFs?

+1 Jeff McPherson 26 days ago in reply to Zhou JianQiang

TI__Mastermind 31605 points

Hi Zhou,

When the level detector returns a max data value (0xFFFF) then that would represent 0dBFS. Further values can be extrapolated from this point.

Best regards,
Jeff McPherson

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TLV320AIC3204: music level detect without minidsp