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

Search:

Type: Posts; User: jonr

Page 1 of 10 1 2 3 4

Search: Search took 0.01 seconds.

  1. Replies
    2
    Views
    107

    Generally yes, sending audio over ethernet and/or...

    Generally yes, sending audio over ethernet and/or IP is increasingly popular.

    Teensy doesn't have much support for it, but there is this:
    ...
  2. Replies
    72
    Views
    948

    I have a philosophical question about clock sync....

    I have a philosophical question about clock sync. Which is better for teensy related, separated audio clock use cases?

    a) just match rates
    b) match rate and phase (like a PLL). If clock A...
  3. Replies
    5
    Views
    77

    I've seen debug log messages like "value too...

    I've seen debug log messages like "value too high", which leaves me lost as to what it means and how to fix it.

    For some use cases, consider using something like:

    LOGD("%s %d %s", "Debug",...
  4. Here is some very general advice. Learn the...

    Here is some very general advice. Learn the basics of LTSpice and use it, even for simple circuits. Never perfect, but it's a great way to learn things like "what would happen if I injected a...
  5. Replies
    72
    Views
    948

    I have some code working that will take a...

    I have some code working that will take a periodic input from any source at any frequency and adjust the teensy audio clock to match it. For example, I'm syncing to a PC sending a single byte via...
  6. Replies
    4
    Views
    96

    I tried it and while changes to...

    I tried it and while changes to CCM_ANALOG_PLL_AUDIO_NUM clearly changes the clock rate, it isn't a simple ratio. You could use trail and error to find the right value. Or use the c1 value from...
  7. Replies
    4
    Views
    96

    I think so, but let us know. I'm working on...

    I think so, but let us know.

    I'm working on some code that will calculate the correction ratio to apply from any kind of periodic communication. But a fixed ratio is fine for some uses.
  8. Replies
    4
    Views
    96

    AUDIO_SAMPLE_RATE_EXACT is a compile time...

    AUDIO_SAMPLE_RATE_EXACT is a compile time setting. You are looking for a run-time clock change, which has to be done differently.

    Using Paul's recent discovery, should be something like:
    ...
  9. > a virtual GND of 1.65V and power the AD8224...

    > a virtual GND of 1.65V and power the AD8224 with +-3.3V)?

    You would want the AD8224 to operate without a virtual ground. And the 2nd stage needs power too. Probably not worth the changes,...
  10. Replies
    72
    Views
    948

    It could be "what the teensy clock registers are...

    It could be "what the teensy clock registers are going to be initially set to". Which, glancing at AudioStream.h, is already sometimes a non-integer number.
  11. Replies
    72
    Views
    948

    I could see a use for an...

    I could see a use for an AUDIO_SAMPLE_RATE_NOMINAL that would always be 44100, 48000 or etc.
  12. Replies
    72
    Views
    948

    I see the clock setting code in these files. ...

    I see the clock setting code in these files. So IMO, yes, it should be consolidated into a single function. Using a double.

    ./avr/libraries/Audio/output_mqs.cpp: int fs =...
  13. You could also add an inverting charge pump - the...

    You could also add an inverting charge pump - the AD8224 will run on 3.3V and -3.3V.
  14. Replies
    72
    Views
    948

    Now we need a PTP like protocol to exchange clock...

    Now we need a PTP like protocol to exchange clock rate information between hosts. Preferably one that is flexible about what the transport is. Serial, RF, ethernet, hardware pin, etc. Is there...
  15. Replies
    72
    Views
    948

    > no more sliding clocks now Just to be clear,...

    > no more sliding clocks now

    Just to be clear, your clocks are still sliding. But perhaps at such a low rate that you don't care.
  16. Your first graph has a scale that goes negative. ...

    Your first graph has a scale that goes negative. But in single ended mode, the output of the ADC is unsigned. Mix up signed and unsigned and you get strange jumps at 32767.
  17. Replies
    72
    Views
    948

    > allows 0%error for all std frequencies More...

    > allows 0%error for all std frequencies

    More precisely, 0% error from the source. But a crystal source always has error, so all you can ever do for the absolute rate is "close enough". Ie, a...
  18. Replies
    72
    Views
    948

    Sounds good. Change the clock setting code to...

    Sounds good. Change the clock setting code to use a large denominator and floating point. Then anyone wanting to tweak rate can a) change AUDIO_SAMPLE_RATE_EXACT at compile time or b) change...
  19. Replies
    72
    Views
    948

    I toggled CCM_ANALOG_PLL_AUDIO_NUM between 2240...

    I toggled CCM_ANALOG_PLL_AUDIO_NUM between 2240 and 2241 every second with no audible effect. This is with SPDIF output to an external DAC.

    For most use cases, only small changes are needed -...
  20. Replies
    72
    Views
    948

    Nice! Kudos for not trusting the manual. ...

    Nice! Kudos for not trusting the manual.

    Add something like PTP and you can get sync, even over wireless.
  21. Replies
    72
    Views
    948

    I see Frank's point. Not sure what I did wrong...

    I see Frank's point. Not sure what I did wrong when I tested it and got a better match between my PC and teensy rate. Perhaps a misleading random change in one of the clocks.

    Looks like it...
  22. Replies
    1
    Views
    78

    I suspect that your best bet is to use what you...

    I suspect that your best bet is to use what you have but add more buffering (to cover the gaps).
  23. Replies
    72
    Views
    948

    As Paul explains, the decimal portion of...

    As Paul explains, the decimal portion of AUDIO_SAMPLE_RATE_EXACT *is* used. On a T4, you can use it (at compile time) to get two asynchronous clocks to be close to the same rate. But clocks change...
  24. Replies
    2
    Views
    89

    You might be able to adapt the "flasher4" code to...

    You might be able to adapt the "flasher4" code to do this.

    https://forum.pjrc.com/threads/29607-Over-the-air-updates/
  25. Replies
    12
    Views
    282

    > We like to detect a clipped audio signal coming...

    > We like to detect a clipped audio signal coming from the mixer

    Remko wants to detect clipping that occurred in the mixer or upstream of it. The signal level is likely to be fine once it gets...
  26. Replies
    6
    Views
    138

    Another common problem is noise from ground...

    Another common problem is noise from ground loops. Don't reference to any noisy ground that you don't have to. Use outputs from an isolated teensy+audio adapter as balanced signals into...
  27. Replies
    12
    Views
    282

    Clipped signals produce more high frequency...

    Clipped signals produce more high frequency energy - which blows tweeters.

    The histogram method here sounds promising. Or do a FFT and compare 3khz and above energy to energy below 3khz.
    ...
  28. Replies
    7
    Views
    127

    It's easier if you make the Teensy/ESP a fixed ip...

    It's easier if you make the Teensy/ESP a fixed ip address web server on your wifi network and then have the PC poll it via http.
  29. Replies
    6
    Views
    138

    Do #1 - teensy headphone jack into mixer line...

    Do #1 - teensy headphone jack into mixer line input.
  30. Replies
    475
    Views
    49,346

    What is the feasibility of adding virtual files...

    What is the feasibility of adding virtual files to MTP? For example, "memory", which would provide read access to all memory in the teensy?
  31. Replies
    11
    Views
    211

    Any easy, standards based way for a PC to access...

    Any easy, standards based way for a PC to access non-volatile data (eeprom or other) in a teensy would be useful. Perhaps virtual files accessed via MTP?

    For example, I run audio convolution...
  32. Thread: i.MX RT1170 ??

    by jonr
    Replies
    3
    Views
    158

    The NXP i.MX RT1176 eval board should be more...

    The NXP i.MX RT1176 eval board should be more widely available in February.
  33. Replies
    11
    Views
    211

    Besides the clear need for more structure on top...

    Besides the clear need for more structure on top of teensy non-volatile storage, there is the barrier-to-change business issue. It should be easy to port software from ESP32 to teensy. The reverse...
  34. Replies
    11
    Views
    211

    Seems like such a library should be built on top...

    Seems like such a library should be built on top of teensy's EEPROM code. For many uses, far less than 64K is adequate.
  35. Replies
    5
    Views
    223

    This is worth reviewing: ...

    This is worth reviewing:

    https://arduino.stackexchange.com/questions/57645/trouble-configuring-arduino-due-spi-to-adc
  36. Replies
    3
    Views
    88

    > I need to acquire 200,00 samples to have a...

    > I need to acquire 200,00 samples to have a correct 100khz samplerate

    I'd word it as "the setting and library will cause the ADC to acquire 200,000 samples/sec to produce the correct output rate...
  37. Replies
    3
    Views
    88

    It tries to produce the derived sample rate that...

    It tries to produce the derived sample rate that you specified (100,000), no matter how much averaging you do. In your example, 200,000 samples/sec need to be taken which is then reduced to 100,000...
  38. Replies
    72
    Views
    948

    Did you try changing AUDIO_SAMPLE_RATE_EXACT as...

    Did you try changing AUDIO_SAMPLE_RATE_EXACT as suggested in #4?
  39. Replies
    72
    Views
    948

    Regarding clock rate sync between two...

    Regarding clock rate sync between two non-wired-together sources, just adding a GPS module to each one might be easier than implementing PTP.
  40. Replies
    72
    Views
    948

    I find the manual quite dense, but as I see it, a...

    I find the manual quite dense, but as I see it, a clock can be applied to the SPDIF_EXT_CLK pin and this can be used as the SPDIF clock, Then the SAIs can use the SPDIF clock as their clock (see...
  41. Replies
    7
    Views
    210

    > will that slow things down If you are...

    > will that slow things down

    If you are concerned about speed, then I encourage you to learn how to measure speed. Search this forum for "ARM_DWT_CYCCNT".
  42. Replies
    72
    Views
    948

    Other than using the hardware audio inputs (I2S,...

    Other than using the hardware audio inputs (I2S, spdif), I'm not aware of any way to get a teensy audio output to precisely sync with an asynchronous clock from another source. I think you could...
  43. The demo here sounds quite effective: ...

    The demo here sounds quite effective: https://www.seeedstudio.com/ReSpeaker-Mic-Array-v2-0.html

    On the other hand, if the source is at a fixed position, it would be interesting to hear how well a...
  44. Replies
    3
    Views
    124

    Try turning off interrupts with cli().

    Try turning off interrupts with cli().
  45. Replies
    42
    Views
    1,770

    Frequent overruns unless I patch the feedback...

    Frequent overruns unless I patch the feedback code in usb_audio.cpp.

    https://forum.pjrc.com/threads/61142-USB-Audio-Frame-Sync-on-Teensy-4-0
  46. Your plan is sound. I'd buy a toslink input...

    Your plan is sound. I'd buy a toslink input module and a relay module (to send the 12V amp on signal). Then it's just software.
  47. > The display then shows 1,178 to 1,182 V...

    > The display then shows 1,178 to 1,182 V (probably RMS).
    > My oscillator (AC coupling) shows me Ue = 352 mVpp / 123 mV RMS.

    I'll assume "oscilloscope". When a multimeter reads ~10x more than an...
  48. What does a multimeter read (at the input pin)...

    What does a multimeter read (at the input pin) for both AC and DC?
  49. What do you get with DC voltages?

    What do you get with DC voltages?
  50. Thread: TDM as slave

    by jonr
    Replies
    13
    Views
    344

    So you want a T4 to produce 2 TDM outputs that...

    So you want a T4 to produce 2 TDM outputs that are precisely time synchronized with each other. I don't know much about it, but will give my thoughts anyway. 6.15 us is a long time for a T4. If...
Results 1 to 50 of 500
Page 1 of 10 1 2 3 4