Forum Rule: Always post complete source code & details to reproduce any issue!

Search:

Type: Posts; User: DD4WH

Page 1 of 10 1 2 3 4

Search: Search took 0.01 seconds.

  1. thanks for the hints on where to get the T4 audio...

    thanks for the hints on where to get the T4 audio board, will try it there.

    I added the code for T3.6 convolution code to the github.

    Have fun with the Teensy!
  2. I have been playing around with the code a couple...

    I have been playing around with the code a couple of days on two hardware setups:

    * T4 and DAC PCM5102a & ADC PCM1808
    * T3.6 and Teensy audio shield rev B

    I have also tried T4 and the Teensy...
  3. Replies
    77
    Views
    11,892

    @LoShu: if you use a Teensy 4.0, things will...

    @LoShu: if you use a Teensy 4.0, things will become much easier, because the T4 uses a Teensyduino version with the new CMSIS lib built-in.

    Have a look at the code here:
    ...
  4. Replies
    13
    Views
    165

    If you could explain to us what you mean...

    If you could explain to us what you mean precisely by "ratiometric", we could be better in answering your questions.

    If "ratiometric" means to you: "The ADC output value is proportional to the...
  5. Hmm, I have gone through the variables again and...

    Hmm, I have gone through the variables again and I fear we cannot save memory when going to a MONO version. These are the variables used in the Stereo version:

    FFT length is 256
    partitionsize is...
  6. Yes, it seems all options work, except the one I...

    Yes, it seems all options work, except the one I am most interested in and which I was originally targeting ;-). If there is any volunteer to put the code into an audio lib LOW LATENCY IMPULSE...
  7. I see you already answered some of your questions...

    I see you already answered some of your questions by yourself :-).

    Here are two possible answers to your "latency in SDR" question:

    https://www.n1kdo.com/sdr-delay-measured/
    ...
  8. Replies
    267
    Views
    59,256

    Tom, you are probably aware of these resources...

    Tom, you are probably aware of these resources already, but at these places I have prepared all the info regarding the Teensy Convolution SDR:
    ...
  9. Replies
    267
    Views
    59,256

    Tom, thanks for your thoughtful comment! When...

    Tom, thanks for your thoughtful comment! When saying OFFTOPIC, I meant that MY comment on the Si570 was offtopic. However, you are right, this is the PJRC TEENSY forum and this thread is on Software...
  10. The partitioned convolution code has been changed...

    The partitioned convolution code has been changed now (is on github), so that any recorded impulse responses can be directly put into the code (without zero insertion).

    If you have impulse...
  11. @tschrama: I see (at least) three different...

    @tschrama: I see (at least) three different applications for low latency partitioned convolution:

    1.) guitar cabinet impulse resonse (IR) filtering: that is already possible with the existing code...
  12. Just to confirm: minimum phase lowpass (real...

    Just to confirm: minimum phase lowpass (real valued) FIR filters built with MATLAB also work well with the code and seem to exhibit low latency (as far as I can measure) and good filter effects....
  13. Hi Brian, yes, the k+31 change is not necessary....

    Hi Brian, yes, the k+31 change is not necessary. The code probably worked from the very beginning, but only with impulse response files, NOT with linear phase FIR filter coefficients (my testing was...
  14. The uniformly partitioned low latency convolution...

    The uniformly partitioned low latency convolution seems to work now with the guitar cabinet impulse files AND with low latency (as far as I can test it here).

    The recent version uses Stereo...
  15. Replies
    267
    Views
    59,256

    OFFTOPIC: I would recommend to no longer use the...

    OFFTOPIC: I would recommend to no longer use the Si570 unless you have a very good reason to do so . . .

    The Si570:
    * needs way too much power supply current
    * is much too expensive
    * is much...
  16. It seems the uniformly partitioned convolution is...

    It seems the uniformly partitioned convolution is implemented correctly, BUT the FIR coefficients are not calculated in the right way. Warren Pratt (the designer of the wdsp library, one of the...
  17. @Brian: I think I found something. Have you got...

    @Brian: I think I found something. Have you got an impulse response like the one you use for your guitar cabinet defined in C as a const variable, something like this:



    const impulse [1024] =...
  18. @Brian: thanks a lot for your very insightful...

    @Brian: thanks a lot for your very insightful comments and observations. I have to admit that the partitioned convolution as it is at the moment still suffers from a problem:

    * if the code stays...
  19. Replies
    267
    Views
    59,256

    @MICUPRE: great to hear its working for you! Just...

    @MICUPRE: great to hear its working for you! Just some short answers to your questions:

    1. https://github.com/DD4WH/Teensy-ConvolutionSDR/wiki/Menu , also have a look at the other entries in the...
  20. Replies
    11
    Views
    215

    same bug here on Windows 8, Arduino 1.8.10,...

    same bug here on Windows 8, Arduino 1.8.10, Teensyduino 1.48: when I upload a sketch on T4, the time is one hour ahead (timezone here is UTC + 1).
  21. Hi Brian, thanks a lot for your excellent...

    Hi Brian, thanks a lot for your excellent measurements and information! I have to digest all that and think about that in order to understand fully.

    * as you said: the good news is that the...
  22. Brian! You already found it! You were just one...

    Brian! You already found it! You were just one off ;-). It had to be (k + 31) % nfor, NOT 32 . . .

    It seems the low latency fast convolution code now does what it should.

    It always has a...
  23. Brian, nice to hear from you and especially that...

    Brian, nice to hear from you and especially that you optimized the low latency convolution object!

    At the moment, there is no need to get your scope (thanks for offering that), because I...
  24. @Brian: before you get out your scope again, one...

    @Brian: before you get out your scope again, one idea: one could test the latency of the code by creating an impulse in software (just a 1.0 in one sample followed by all 0.0 samples) and then output...
  25. Replies
    3
    Views
    132

    Hi Eric, RTTY decoding as a special case of...

    Hi Eric,

    RTTY decoding as a special case of AFSK is implemented on Teensy here:

    https://www.kk5jy.net/modem-v2/

    and (two different decoders) here:
    ...
  26. The Teensy 4.0 seems to be able to perform a...

    The Teensy 4.0 seems to be able to perform a real-time two channel FIR lowpass filter with up to 21632 taps for audio I2S signals . . .

    See this code below which filters I2S audio (Stereo: left &...
  27. Replies
    267
    Views
    59,256

    @Joe: OK, now I understand, you mean 135.600kHz,...

    @Joe: OK, now I understand, you mean 135.600kHz, not MHz :-). Yes, that is the expected behaviour of the SDR code to start with that band and that frequency!



    No, your configuration is not the...
  28. Replies
    267
    Views
    59,256

    @Joe: I do not know, because your setup is...

    @Joe: I do not know, because your setup is unknown to me. For the radio you need: T4, ADC, DAC, Si5351 LO, ILI9341 TFT, encoders, buttons, and a quadrature sampling detector (and RF input lowpass or...
  29. Replies
    267
    Views
    59,256

    Do not hesitate to ask if you have any problems...

    Do not hesitate to ask if you have any problems with the code!
  30. Replies
    267
    Views
    59,256

    @Joe: the only reason I did not use PJRCs audio...

    @Joe: the only reason I did not use PJRCs audio board is that it did not work with my wild wiring :-). Now with version D available it is no problem to use the PJRC audio board and the T4. The...
  31. Replies
    267
    Views
    59,256

    @Joe: the Convolution SDR makes only very limited...

    @Joe: the Convolution SDR makes only very limited use of objects, it uses the audio lib queue object to gather the audio files from I2S and to push the files to I2S after treatment.

    ALL the audio...
  32. Replies
    267
    Views
    59,256

    @MICUPRE yes, a larger TFT with the ILI9341...

    @MICUPRE

    yes, a larger TFT with the ILI9341 controller and the same number of pixels should work. If you want higher resolution, you would have to completely reprogram the display.

    Softrock...
  33. Replies
    267
    Views
    59,256

    Joe, not sure if I understand correctly: Do...

    Joe,

    not sure if I understand correctly: Do you mean a sketch to check functioning of the T4 and audio board?

    You could use the StereoPassThrough example from the audio lib.

    Or try the...
  34. Oh, I was not aware that the syntax is still...

    Oh, I was not aware that the syntax is still evolving, that explains a lot.

    For the moment, I tried to reproduce your RAM-Info, but I could not get imxrt-size.cpp to run . . .

    So I put...
  35. Thanks Kurt! I still have problems understanding...

    Thanks Kurt! I still have problems understanding the syntax . . .

    Maybe it would be good to give some dummy examples and let you experts comment on that ?

    Is the following syntax/use example...
  36. @Paul: thanks a lot for the graph and the...

    @Paul: thanks a lot for the graph and the explanation! That is what I have been waiting for :-).

    It was very hard (and still is hard) to understand how the memory is composed and especially how to...
  37. Replies
    267
    Views
    59,256

    Hi Joe, I am pretty sure you did not have the...

    Hi Joe,

    I am pretty sure you did not have the Teensy Convolution SDR on a Teensy 3.2, because the Teensy Convolution SDR does work only with Teensy 3.6 or Teensy 4.0.

    It must have been a...
  38. Replies
    267
    Views
    59,256

    The first one is intended and is no error ? It...

    The first one is intended and is no error ? It compiles for me and the fast log-approximation code is being used by the spectrum display code

    For the second problem you have to define your own...
  39. Replies
    4
    Views
    300

    First of all, it would be good to know what you...

    First of all, it would be good to know what you want to do with the FFT!? Then it would be easier to decide whether you need a real FFT or a complex FFT.

    Regarding the code you posted:

    * you...
  40. Possibly! Would be interested to hear if it...

    Possibly!

    Would be interested to hear if it works and please post a photograph of your setup.
  41. Replies
    3
    Views
    149

    You could also have a look here, Brian has done...

    You could also have a look here, Brian has done something useful for the Teensy 3.6:

    https://circuitcellar.com/cc-blog/fancy-filtering-with-the-teensy-3-6/
    ...
  42. I never had crackling noise with DAC alone, the...

    I never had crackling noise with DAC alone, the ADC was the problematic part, so my thought was to add 100 Ohm resistors to all ADC clock lines (and to the master clock for DAC). I did not check...
  43. Replies
    267
    Views
    59,256

    Thanks to Henk, we now have an Excel file...

    Thanks to Henk, we now have an Excel file summarizing all pin connections between the

    ADC, DAC, T4 and the ILI9341 TFT for the current T 4.0 Convolution SDR
    ...
  44. Replies
    4
    Views
    300

    Yes, you can find an example here:...

    Yes, you can find an example here: https://forum.pjrc.com/threads/57267-Fast-Convolution-Filtering-with-Teensy-4-0-and-audio-board?highlight=convolution

    It uses a forward 4096-point-FFT, a...
  45. Replies
    4,349
    Views
    473,145

    @defragster @mjs513 , just for your records My...

    @defragster @mjs513 , just for your records

    My experience with overclocking is the following:

    Yesterday, I could run your Buddhabrot example at 1008MHz for more than one hour without problem...
  46. Replies
    267
    Views
    59,256

    Thanks again for pointing me to the bugs! Now the...

    Thanks again for pointing me to the bugs! Now the software compiles for Teensy 3.6 (latest version is on github).

    I have also tested the fixed version on my T3.6-based SDR and it plays fine.
    ...
  47. Replies
    267
    Views
    59,256

    Hi MICUPRE, sorry for that: I seem to have...

    Hi MICUPRE,

    sorry for that: I seem to have messed up the Teensy 3.6 configuration while I was working on the T4 version (which uses another TFT library and thus some other commands for printing...
  48. Replies
    11
    Views
    356

    Installed Ardunio 1.8.10 and Teensyduino 1.48 ...

    Installed Ardunio 1.8.10 and Teensyduino 1.48

    Same effect: if I compile with "Optimize: smallest code", the script does not run properly when I set the limit above 20: it only prints out "Before...
  49. Replies
    11
    Views
    356

    thanks for testing! Tested it again to be sure...

    thanks for testing! Tested it again to be sure (with while(!Serial) :-), but same problem occurs here: if I use "Optimize: smalles code" it works with 20, but not with 50 (prints out "Before...
  50. Replies
    11
    Views
    356

    @manitou: thanks for the hint! However, it did...

    @manitou: thanks for the hint! However, it did not help.

    The real problem I had was that in the Arduino compiler setting I had "optimize: smallest code" (which I did not realize . . .). That...
Results 1 to 50 of 492
Page 1 of 10 1 2 3 4