Teensy Convolution SDR T4 and Audio Board Rev D

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f6duk

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Help needed Teensy Convolution SDR T4 and Audio Board Rev D

Dear all
I need help! I could compile the software menus are working as they should frontend is OK wit correct frequencies. But I am stuck with linking the T4.0 and audio board SGTL5000 rev D Teensy sits on audio board

with a scope on outputs of t4 I see following:
on pin 23MCLK Clock I have 45.157 Mhz I have the 11.289 for a couple of milliseconds after booting
on pin 20LRCLK I have 176Khz
on pin 21BCLK I have 11.289Mhz

Looks as everything is 4 times requested frequency!!!

Did I miss something to (un)comment? wrong audio library? using teenduino one

Any clues widely appreciated with many thaks

73,s Hubert F6DUK
 
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I believe the Convolution SDR code sets this explicitly as it needs as much baseband bandwidth as possible.
 
I think that 45Mhz is ways to much as MCLK for the SGL5000, I hvae the requested 11Mhz during booting ut then goes to 45 Mhz and of course it doesn't work.
 
I guess the code is configured for a faster chip then, the SGTL5000 only goes to 96kSPS I read.

The 44.1k setting at startup is probably the audio library default - I don't know the innards of the
Convolution SDR code though, its a guess. This ought to be configurable, so you should be able
to try setting to 96kSPS
 
I guess the code is configured for a faster chip then, the SGTL5000 only goes to 96kSPS I read.

The 44.1k setting at startup is probably the audio library default - I don't know the innards of the
Convolution SDR code though, its a guess. This ought to be configurable, so you should be able
to try setting to 96kSPS

Checkout this thread about Convolution SDR - yes the system's designed around a different audio
chip... https://forum.pjrc.com/threads/40590-Teensy-Convolution-SDR-(Software-Defined-Radio)
The first posting mentions a particular pcb, but the link to the schematic is broken.
 
Hi!
The Teensy Convolution SDR code works with many hardware configurations including different I2S codecs, I have built and tested a few of those types:

* T4.1 & audio shield rev D
* T4 & PCM5102 & PCM1808
* T3.6 & audio shield rev B
* T3.6 & PCM5102 & PCM1808
* ...

I am not able to understand what your problem is here . . .

* which software switches (#defines) did you comment out during compile?
* Do you have working audio? Which demodulation type are you using?
* the sample rate is adjustable in the menu, which sample rate did you choose?
* what is your hardware frontend setup? Do you use a Tayloe type (QSD) frontend?
* please give us some more information :)

Also it would be good if you put your question in the Teensy Convolution SDR thread, so we have the information held together in one thread:

https://forum.pjrc.com/threads/40590-Teensy-Convolution-SDR-(Software-Defined-Radio)/page23
 
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