New Audio Board! TI TLV320AIC3206

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chipaudette

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Hi All,

As part of my work on an open source platform for hearing aid algorithms, we made a new audio interface board, much like the Teensy Audio Board. Our board, though, is based on the Texas Instruments TLV320AIC3206 (aka. "3206"). Our goal was to make a board with quieter inputs so that we'd have more dynamic range. The 3206 was a helpful step to achieving that.

I really like working within the Teensy audio library ecosystem. So, in making this new board, we wrote a control module (like the SGTL5000 control module for the Teensy Audio Board) that allows the 3206 to work with the Teensy audio library. The 3206 is an I2S device just like the SGTL500, so you send and receive audio data to the 3206 using the same I2S input and output functions as used for the Teensy Audio Board. Pretty sweet!

If you're interested in details (schematic, BOM) or in my measurements of its self-noise and dynamic range, you can check it out here: http://openaudio.blogspot.com/2017/03/tympan-self-noise.html

TympanSelfNoiseLeadPic.png

CompareDynamicRange.png

I'm surprised at how easy it was to plug this new hardware into the Teensy audio ecosystem. Very fun.

Chip
 
I've updated the header comments and improved the attribution to my buddy who did the actual writing. Both files have been updated. Thanks so much for your interest!

Chip
 
Yeah, I gotta fix the PCB layout first. DIN and DOUT were swapped. I fixed the schematic but not (yet) the layout.
 
I had a brief look at the data sheet and the AIC3206 looks really nice. An audio-board 2.0 with this chip would be great!
 
A question, can the ADC-Part of the TLV320AIC3206 really output (3206->Teensy) samples with 192kHz, or is 48kHz with oversampling ? I need a input-sampling rate of 192kHz. The Datasheet is a bit unclear to me.
 
I can't speak to 192 kHz. I'm mainly running at 44.1 kHz and slower. I have run it up to 96 kHz using the increased I2S clock rates introduced by others (you?) in a different thread. It worked fine at 96 kHz (I can successfully record and demodulate ultrasonic signals around 40 kHz), though the system doesn't seem to run as stable as I'd like...it would occasionally get to a state where the Teensy and everything would hang. Not cool. Since the high sample rates weren't my mission, I didn't really push the issue.

I'm away from my hardware right now, so I can't be more help regarding 192 kHz. Sorry.

Chip
 
My question was re: the chip only, as i don't understand the datasheet here (or i didn't find the right page..)
 
Yeah, I could't find any clear statements in the datasheet or the application guide. As you yourself said, the product page claims 192 kHz, but I didn't find any substantive discussion of it in the technical docs.
 
Does the USB audio module in the Teensy Audio Library run at sample rates other than 44.1 kHz? If so, tomorrow, I can crank up the I2S clock speeds to support 192 kHz and see what kind of bandwidth I achieve!

Do you know, does (or can) the USB audio module support these higher speeds?

Chip
 
Does the USB audio module in the Teensy Audio Library run at sample rates other than 44.1 kHz? If so, tomorrow, I can crank up the I2S clock speeds to support 192 kHz and see what kind of bandwidth I achieve!

Do you know, does (or can) the USB audio module support these higher speeds?

Chip

I don't know.
Maybe Paul can answer this ?
 
I published the schematic and the gerbers on the Tympan GitHub: https://github.com/Tympan/Tympan_Library/tree/master/hardware/Tympan_PCB. Note that the Gerbers still have critical errors: the I2S data lines (in and out) are swapped. The PDF schematic has been corrected, but the gerbers have not.

My buddy, Joel Murphy, is probably going to fix the gerbers and make a run of a few dozen boards. I think that he's planning on including a Teensy 3.6 as part of the build (though you can probably tell him otherwise). If you're interested, you can visit this page and sign-up for notifications: https://tympan.org/shop/

If this constitutes unacceptable spam, I apologize and would be happy to delete this post.

Chip
 
Hey @chipaudette, I've just signed up there. do you think it will be a nice platform to develop realtime instrument effects?
Thanks
 
The Tympan board is aimed at different goals than real-time instrument effects, so things like the on-board microphones may not be very usefull to you. Also, the packaging isn't quite right (you probably want 1/4" phono plugs, not 1/8" guys). And do you really want a LiPo battery (and built-in charging elements) for an instrument effects box? Bluetooth and SD card? Probably not.

Also, this system doesn't have external RAM...you get exactly what the Teensy 3.6 has. So, if you have long echos or reverbs or sampling that you want to do, this system may be insufficient.

But, the audio codec at the heart of this board is pretty dang good (for a low-power codec). That part of our system might suit you very well.

I think that your choice will come down to price. Since its mix of features might not be your ideal mix of features, you'll have to decide if the price is worth it.

Chip
 
Thanks @chipaudette. Yes it would be great to try out this board, but one thing I like a lot on Teensy Audio Board is I can extend it with RAM or SerialFlash (which I'm using a lot lately).
I know you have a finished design but it would be great to have this same feature there too.
https://www.pjrc.com/store/teensy3_audio_back.jpg

Plugs are no problem for me, and yes lots of features I wont use but mainly I'll be using to make a personal prototype.
 
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