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

Search:

Type: Posts; User: MarkT

Page 1 of 8 1 2 3 4

Search: Search took 0.01 seconds.

  1. Replies
    2
    Views
    77

    Are you trying to do half-duplex on a single...

    Are you trying to do half-duplex on a single wire, as opposed to full duplex using two signals, each uni-directional?
  2. The problem with ambient noises is they are very...

    The problem with ambient noises is they are very directional, and the human auditory system does a very good job of
    isolating each noise spatially (two ears). A single small microphone will not do...
  3. The headphone output is as I understand is not...

    The headphone output is as I understand is not ground referenced, ie HPVGND is a DC level that must
    not be connected to 0V ground (well not at DC for sure).
  4. Replies
    19
    Views
    383

    Yes, I reckon, but make sure the trace between...

    Yes, I reckon, but make sure the trace between the pin and cap isn't too skinny and runs over ground-plane
    to keep the inductance low.

    They are probably in the chip itself, I'd check the...
  5. Replies
    19
    Views
    383

    Really? You are allowed to populate the region...

    Really? You are allowed to populate the region of your pcb between the header rows, so you only lose those
    rows of connectors, and if you use surface-mount connectors you only lose pcb area on one...
  6. Replies
    5
    Views
    201

    In that case I'd suggest rather than editing...

    In that case I'd suggest rather than editing AudioStream.h, just touch it before compiling if you have overridden the sample
    rate - that way the sources to the library aren't changed, just the...
  7. Nice! Is the audio handled?

    Nice! Is the audio handled?
  8. Replies
    1
    Views
    143

    6 foot run is too long for reliable single-ended...

    6 foot run is too long for reliable single-ended fast logic signals. 6 inches is more normal :)

    You'd need to use something like RS485, LVDS, or an old fashioned line-driver / line-receiver pair...
  9. Second that - its a low-impedance stepper so...

    Second that - its a low-impedance stepper so requires current drive, DRV8825 modules and A4988 modules are the
    way to go, and you'll need to set to _0.35A_ max current setting for that motor. If...
  10. Thread: audio clock slip

    by MarkT
    Replies
    15
    Views
    389

    I don't know if you can still get bargains, but...

    I don't know if you can still get bargains, but you used to be able to pick up a used rubidium atomic clock module for
    $100 or so (typically these come from mobile phone base station upgrades).
  11. Replies
    5
    Views
    201

    I think you just have to #define the constant...

    I think you just have to #define the constant before #including AudioStream.h, as it doesn't override the define if already set.
  12. Thread: audio clock slip

    by MarkT
    Replies
    15
    Views
    389

    0.2ppm is the sort of accuracy you might see in a...

    0.2ppm is the sort of accuracy you might see in a brand new RF spectrum analyzer!

    Perhaps this is the future and will finesse the issue:...
  13. Replies
    8
    Views
    366

    Breakout boards with an I2S DAC on them do...

    Breakout boards with an I2S DAC on them do exist...
  14. Replies
    2
    Views
    189

    Should be fine. An LED + resistor is a load, not...

    Should be fine. An LED + resistor is a load, not a short circuit, so it won't overcome ground which will be 0V
    whatever. I'd double check there's no internal connections with a multimeter though -...
  15. The problem with that would be the Teensy isn't...

    The problem with that would be the Teensy isn't able to switch the optocoupler through the resistors...
    Open drain is the acknowledged way to do something like this, its often used for chip reset...
  16. Replies
    8
    Views
    366

    For the popping are you sure the audio stream to...

    For the popping are you sure the audio stream to the SGTL is getting all zeroes when you change volume? If so and the
    RH channel is popping that's the chip itself, not a discontinuity in data. Not...
  17. Replies
    39
    Views
    1,142

    You clearly haven't checked this in the source...

    You clearly haven't checked this in the source code - I'd recommend getting upto speed with the Audio lib internals
    to gain a deeper understanding of what goes on, AudioStream.h & AudioStream.cpp...
  18. Simple reversal is by definition not realtime. ...

    Simple reversal is by definition not realtime. You could process short samples and reverse each one, but
    then you have to have a delay. You also have to have some algorithm for breaking the...
  19. Replies
    21
    Views
    578

    Not sure what you are asking.

    Not sure what you are asking.
  20. Replies
    39
    Views
    1,142

    I suspect there's a uint16_t method for println. ...

    I suspect there's a uint16_t method for println. Note that int16_t and int32_t will not implicitly cast
    to unsigned types as negative values cannot be represented.
  21. Replies
    8
    Views
    366

    Are you talking to the display (ie using SPI bus)...

    Are you talking to the display (ie using SPI bus) when the high pitched noise is audible? Or could it be
    the PWM for the LED backlight?

    The pops will be a DC offset on the right hand channel I...
  22. Replies
    39
    Views
    1,142

    You aren't getting 32 bits, its just that println...

    You aren't getting 32 bits, its just that println only has a method for int, not int16_t, so the value is implicitly converted from
    16 bit to 32 bit (the natural size of int) by the compiler so it...
  23. Replies
    8
    Views
    317

    Actually its complex (maths joke...)

    Actually its complex (maths joke...)
  24. Replies
    8
    Views
    317

    Then you need to have your frequency variable i,...

    Then you need to have your frequency variable i, and cos and sin to convert that into position on the unit circle,
    all that remains is to evaluate that z value for all the poles and zeroes,...
  25. Replies
    39
    Views
    1,142

    You may be able to work in-place if using...

    You may be able to work in-place if using receiveWritable() and the endianness is correct for the algorithm,
    if copying out and back you simply copy back into the writeable audio block for each...
  26. Replies
    8
    Views
    317

    Filter responses are calculated from the poles...

    Filter responses are calculated from the poles and zeroes of the filter. Are we talking about
    analog filters or digital?
  27. That's the difference between a microcontroller...

    That's the difference between a microcontroller and a computer - the microcontroller runs just the
    program you write (plus the libraries it uses), and nothing else, no operating system, nothing in...
  28. You need to use CHANGE, not RISING or FALLING on...

    You need to use CHANGE, not RISING or FALLING on an ISR used for decoding a quadrature encoder, otherwise
    oscillating values will invariably be miscounted like this(*). Its very common to have...
  29. A hex file is a precompiled binary (meant for a...

    A hex file is a precompiled binary (meant for a particular board only), not a source program. Different things.
    Skip that step perhaps and go to the next. You'd rarely ever explicitly upload a...
  30. Its very rare that a new chip come in anything...

    Its very rare that a new chip come in anything but surface mount, through hole is for legacy devices (new
    opamps sometimes have DIP versions for upgrading old kit). The 3.3V CMOS logic families are...
  31. Replies
    15
    Views
    351

    But not for generating a 10V signal as its...

    But not for generating a 10V signal as its limited to a 5V supply range...
  32. Replies
    7
    Views
    201

    Working for me on Firefox 77.0.1 and Chrome...

    Working for me on Firefox 77.0.1 and Chrome 85.0.4183.102 on MacOS.
  33. As you've discovered you can't use a quadrature...

    As you've discovered you can't use a quadrature encoder library to count pulses on a single pin, as
    quadrature requires both signals to change to go round the state transition diagram. If only one...
  34. Replies
    5
    Views
    542

    Assume its small, a few mA. This is a very...

    Assume its small, a few mA. This is a very complex chip with loads of I/O pad drivers, so they will be physically
    very small on the die, and thus not able to handle much continuous current without...
  35. Replies
    39
    Views
    1,142

    My code copies the data out to process it - if...

    My code copies the data out to process it - if you want to alter the original block you need to
    make sure you've got it in write mode to start with, and in that case you can avoid copying and
    just...
  36. Replies
    39
    Views
    1,142

    Pointer type casting is compile-time operation,...

    Pointer type casting is compile-time operation, nothing actually happens at runtime, its the same bits.
  37. An external ADC with separate analog and digital...

    An external ADC with separate analog and digital supply pins is recommended to get clean readings - internal ADC on
    a complex processor chip are always a compromize in performance (but often very...
  38. The first AudioStream object to be initialized in...

    The first AudioStream object to be initialized in the code that is capable of driving the update mechanism will be the one
    selected to do it, so make sure the AudioOutputI2S dummy object occurs...
  39. Replies
    3
    Views
    194

    Then it might be worth having a go - the...

    Then it might be worth having a go - the processor is obviously gone, but its possible other things have followed.

    With a BGA package I suggest finding some video tutorials - in theory you remove...
  40. Replies
    3
    Views
    194

    Do you have a hot-air rework station?

    Do you have a hot-air rework station?
  41. Replies
    82
    Views
    1,265

    I would suggest using uint16_t for 16 bit...

    I would suggest using uint16_t for 16 bit unsigned int, int16_t for signed 16 bit int, etc etc. And you'll have
    to check endianness too - you might need to write marshalling/unmarshalling code if...
  42. Reckon this is the mistake: if (new_value2

    Reckon this is the mistake:


    if (new_value2 < min_value1) min_value2 = new_value2;
  43. Replies
    2
    Views
    196

    Yes Teensy's run off USB power. LiPo batteries...

    Yes Teensy's run off USB power.

    LiPo batteries are not 5V. Thus you need either 2S into a voltage regulator to make 5V, or 1S into a boost-converter to
    make 5V.

    I recommend using a...
  44. Replies
    8
    Views
    269

    Note that %2d or %.2d as a format string doesn't...

    Note that %2d or %.2d as a format string doesn't limit the length of its expansion to 2 characters. So allocate
    enough characters in the buffer for the largest integer plus a few more - even if...
  45. If you want to strengthen the pull-ups from 10k...

    If you want to strengthen the pull-ups from 10k to 5k, all you need to do is piggy-back extra 10k resistors on top of
    (and thus in parallel with) the existing pull-ups on the PCB. This is easier...
  46. I need a circuit diagram to understand this...

    I need a circuit diagram to understand this fully. When asking a technical question you need to be much less vague:

    "I have a stand alone 4 LED driver" - no part number, no datasheet, nothing to...
  47. Replies
    39
    Views
    1,142

    AES blocks are 16 byte, default audio lib blocks...

    AES blocks are 16 byte, default audio lib blocks are 256 byte, so process 16 AES blocks per audio lib block.
    So something along the lines of:


    uint8_t * bptr = (uint8_t*) (block->data) ; //...
  48. Replies
    25
    Views
    527

    Datasheet links? I need to know the _full_ tech...

    Datasheet links? I need to know the _full_ tech specs, not just part numbers, in order to see what's what. In particular
    motors are often available with multiple winding versions, and this is what...
  49. Replies
    139
    Views
    7,757

    Why any inaccuracy? Single-sample granularity is...

    Why any inaccuracy? Single-sample granularity is just a case of returning the sample number for each timestamp,
    or you can generate a click on a generated click-track stream to provide...
  50. Replies
    39
    Views
    1,142

    128, you have not changed anything. AudioMemory...

    128, you have not changed anything. AudioMemory takes the number of _blocks_ to pre-allocate space for.

    The samples per block is set by this code in AudioStream.h:


    #ifndef...
Results 1 to 50 of 382
Page 1 of 8 1 2 3 4