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

Search:

Type: Posts; User: MarkT

Page 1 of 10 1 2 3 4

Search: Search took 0.01 seconds.

  1. Since the system samples at 44100Hz, 22kHz is...

    Since the system samples at 44100Hz, 22kHz is indeed the maximum frequency supported by the Audio library, in its out-of-the-box configuration. Increasing this is possible, there are various threads...
  2. Replies
    2
    Views
    91

    The AudioOutputI2S2slave class is work in...

    The AudioOutputI2S2slave class is work in progress I think - its commented out in the sources at the moment.

    The classes are named from the Teensy's point of view - ie the slave classes work with...
  3. I guess that's perfectly possible - you'd need to...

    I guess that's perfectly possible - you'd need to ensure suitable scaling of the received signal to the right level for best sensitivity without clipping too readily.
  4. Replies
    4
    Views
    96

    Or I think you can use AudioOutputI2S and...

    Or I think you can use AudioOutputI2S and AudioOutputI2S2 together if on an Teensy 4.x
  5. Pretty sure it doesn't from what I've seen here...

    Pretty sure it doesn't from what I've seen here (not played with it myself)
    USB doesn't run on a 44.1kHz clock, so I presume it can't do the timing for the library like the I2S hardware.

    If you...
  6. Replies
    7
    Views
    138

    FYI: surface mount resistors are identifiable as...

    FYI: surface mount resistors are identifiable as they are nearly always black on top with white printing on them
    showing the value (unless really tiny) they also have metal endcaps.

    Brown/tan...
  7. You need at least one class that generates...

    You need at least one class that generates regular interrupts to fire up the whole audio library - try adding one of
    the I2S classes. I suspect the mono and stereo analog inputs differ in this.
  8. The DMG3406L is only rated for 4.5V gate drive,...

    The DMG3406L is only rated for 4.5V gate drive, but will probably work at 3.3V (for these low currents).
    You need to use a switching configuration when switching, ie a common-source circuit with the...
  9. Replies
    196
    Views
    36,873

    Its all too credible that just-in-time supply...

    Its all too credible that just-in-time supply chains are very brittle to unexpected disruptive world events,
    since by its nature nearly everything is on the critical path leading to cascades of...
  10. Replies
    5
    Views
    253

    You can use the main high current wiring as a...

    You can use the main high current wiring as a shunt, basically tapping into it at two points for a Kelvin connection. This isn't
    ideal as the tempco. of copper is quite high compared to most...
  11. Replies
    11
    Views
    372

    A bare FFT produces an amplitude spectrum - the...

    A bare FFT produces an amplitude spectrum - the values are related to the power in each frequency bin, so more level
    means larger values. If you want to normalize this somehow you have to decide...
  12. Replies
    2
    Views
    215

    Audacity has 0dB as full scale, no headroom. ...

    Audacity has 0dB as full scale, no headroom.

    WAV samples are signed unless 8 bit, IIRC. For 16 bit that's +/-16384 for -6dB.

    I just use wav files and chop the header off if needed raw.


    ...
  13. Replies
    11
    Views
    372

    You always need to call AudioMemory - perhaps...

    You always need to call AudioMemory - perhaps look at a working example program for the Audio library, there are several preloaded into the IDE
  14. The problem was the LED current was sharing the...

    The problem was the LED current was sharing the same ground wire/connections as the audio signal. Wires have resistance
    (a few milliohms per inch or so, but depends on the gauge of course),...
  15. I don't see the problem, an array of voltage...

    I don't see the problem, an array of voltage dividers into an 8-channel ADC does the job, nice and simple. Yes you
    need suitable precision to address the dilution of precision, but its not like...
  16. Not sure I can figure out what you'd done without...

    Not sure I can figure out what you'd done without a circuit diagram....
  17. Don't touch it then! Better still just ground...

    Don't touch it then! Better still just ground the mic input.

    The problem is that the 2k2 resistor couples the input to the supply rail, and the supply rail has some output modulated on it.
    With...
  18. Replies
    11
    Views
    372

    You need something that generates interrupts to...

    You need something that generates interrupts to fire up the audio chain otherwise nothing happens. Add an I2S input or output object perhaps?
  19. Replies
    8
    Views
    270

    Its standard for full blown operating system...

    Its standard for full blown operating system TCP/IP stacks, that's not the same as being supported on
    microcontrollers - corners are often cut on less resource-rich hardware (for instance its not...
  20. No you don't need to solder them together - you...

    No you don't need to solder them together - you can use female headers on the shield so the Teensy can plug into the shield for instance,
    or use male headers on both and connect via a breadboard and...
  21. Replies
    8
    Views
    270

    Hmm, I'd still be worried IP fragmentation isn't...

    Hmm, I'd still be worried IP fragmentation isn't handled well - it looks complicated (IPv4 v. IPv6 issues) and its probably more reliable to avoid it, especially for UDP.
  22. Could that simulation be mapping into Audio...

    Could that simulation be mapping into Audio library flowgraph?
  23. Replies
    8
    Views
    270

    The MTU is the hardware limit... Split your...

    The MTU is the hardware limit...

    Split your data into packets, each packet prefixed by a message sequence number and a part number, like
    0,0 first part of message 0
    0,1 second part of message 0...
  24. % 60 means modulo 60 - maps to a 60 count cycle...

    % 60 means modulo 60 - maps to a 60 count cycle
    / 30 - integer division by 30 splits the range 0..59 into 0..29 (as 0) and 30..59 (as 1).
  25. That's a real signal from the sensors isn't it? ...

    That's a real signal from the sensors isn't it? A simulated signal would just be generated programmatically with no reference
    to anything else.
  26. Replies
    8
    Views
    270

    Ethernet MTU is usually 1500 so I'm surprised...

    Ethernet MTU is usually 1500 so I'm surprised even 2048 works.
    Sequence and part numbers?
  27. You'd never normally test for continuity through...

    You'd never normally test for continuity through a chip, but between points supposedly on the same net. However if there
    is a break in continuity that can then result in the continuity test current...
  28. Thread: usb to fft1024

    by MarkT
    Replies
    2
    Views
    132

    You need to fire up the audio chain which means...

    You need to fire up the audio chain which means including at least one class that can drive it, such as i2s_output.
    From what I recall USB doesn't drive the chain, its expects something else to do...
  29. Oh yes, I missed that - so there is one exception...

    Oh yes, I missed that - so there is one exception for pin 30, and some other pins to handle - not sure there's anything to
    gain integrating them into a single lookup though - reading the ADC will...
  30. Its just a simple formula for that pattern: ...

    Its just a simple formula for that pattern:


    digitalWrite (30, EncoderCount1 % 60 / 30);


    The repeat is every 60, not every 30 - not sure people are paying attention :)

    BTW if you ever...
  31. Replies
    6
    Views
    247

    Well that white deposit came from something. You...

    Well that white deposit came from something. You absolutely need flux to solder successfully, BTW. Perhaps you had rosin-cored solder without realizing it?
  32. Replies
    6
    Views
    247

    What was the flux though? If that's acid flux...

    What was the flux though? If that's acid flux you need to wash it off pronto with distilled water, then finish with a PCB cleaner or IPA.
    Electronics requires rosin flux to prevent corrosion damage...
  33. Replies
    6
    Views
    247

    Those white stains look wrong - was the wrong...

    Those white stains look wrong - was the wrong sort of flux used?
  34. Replies
    5
    Views
    239

    I'd be worried that sometime else is using the...

    I'd be worried that sometime else is using the pin digitally and this is the effect of an input gate or Schmitt-trigger or some such.
    What is the impedance of the potentiometer?
  35. Replies
    7
    Views
    256

    The pin will necessarily be analog multiplexed to...

    The pin will necessarily be analog multiplexed to the ADC, so no processing delays, just the propagation time of a CMOS
    transmission gate.
  36. Replies
    1
    Views
    193

    You are perhaps selecting only small speakers, in...

    You are perhaps selecting only small speakers, in general small speakers don't do low frequencies, you'll need a larger one -
    a key specification is efficiency (aka sensitivity), usually given as...
  37. As an exercise for the reader, use serial as 3...

    As an exercise for the reader, use serial as 3 bit PWM with noise-shaping to generate high quality class D output!
  38. Firstly change one of the IR LEDs to a visible...

    Firstly change one of the IR LEDs to a visible LED during testing so you can be sure if its working without needing some sort of
    near IR camera.

    Use 330 ohm resistors, not 220, those will...
  39. Did you think of using a UART at 400kbaud, 8N1,...

    Did you think of using a UART at 400kbaud, 8N1, send 8 0xF0 bytes. That's active low, but you can invert if you need.
  40. Thread: Comb Filter

    by MarkT
    Replies
    7
    Views
    2,194

    Digital filters don't have a frequency control,...

    Digital filters don't have a frequency control, the filter locks the frequencies into the impulse response. You have to generate different filters for different frequencies - not convenient for a...
  41. Depends on the performance you want - even a very...

    Depends on the performance you want - even a very drunk person can keep their balance, just don't expect it to be as solid
    as someone with fast reactions! Same with any control loop - latency will...
  42. Replies
    26
    Views
    659

    I'm simply pointing out radio is not normally...

    I'm simply pointing out radio is not normally full-duplex, but half-duplex, by its nature. You transmit a packet, switch to RX and await the reply, etc etc.
    So I don't see why you need full-duplex...
  43. Replies
    26
    Views
    659

    Now that is useful information. Problem is when...

    Now that is useful information. Problem is when you transmit on one Lora module it will temporarily deafen the other one, so you
    won't be able to avoid packet loss unless you can separate the two...
  44. Thread: Comb Filter

    by MarkT
    Replies
    7
    Views
    2,194

    The problem the OP had was that AudioEffectDelay...

    The problem the OP had was that AudioEffectDelay doesn't do sub-sampletime delays, only integer multiples of the
    sampletime, so the comb frequencies available were quantized. Sub-sample delay...
  45. Replies
    26
    Views
    659

    Each device on an SPI bus needs its own chip...

    Each device on an SPI bus needs its own chip select (aka slave select) any pin can be used as a chip select, check out the
    SPI examples perhaps.
  46. Replies
    26
    Views
    659

    Are you expecting both modules to operate...

    Are you expecting both modules to operate simultaneously without interfering with each other? Perhaps you only
    need to connect them to the same SPI bus?
  47. Replies
    3
    Views
    234

    Its standard practice to use conformal coating...

    Its standard practice to use conformal coating for pcbs exposed to moist air - it will lengthen the lifetime for sure as unprotected boards that get condensation on will have the traces dissolve...
  48. Replies
    4
    Views
    184

    These are hardware mappings set in stone (well...

    These are hardware mappings set in stone (well silicon). Short of overriding all the relevant #defines for the I2C symbols
    I don't see a way.
    Why would this matter? Just document it! Or wrap in...
  49. Replies
    28
    Views
    845

    Who knows - you certainly shouldn't expect...

    Who knows - you certainly shouldn't expect datasheet performance if you neglect analog decoupling.
  50. Replies
    28
    Views
    845

    You're missing the 1uF decoupling cap on AVdd...

    You're missing the 1uF decoupling cap on AVdd mentioned in the datasheet...
Results 1 to 50 of 500
Page 1 of 10 1 2 3 4