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

Search:

Type: Posts; User: palmerr

Page 1 of 2 1 2

Search: Search took 0.00 seconds; generated 1 minute(s) ago.

  1. Excellent! Now you have the electronics...

    Excellent!

    Now you have the electronics working the fun can really begin.
  2. Replies
    6
    Views
    149

    An additional option is to use MEMS microphones...

    An additional option is to use MEMS microphones which often communicate directly via I2S or SPI.

    There's a good description in this document...
  3. Steer away from tie clip microphones - they...

    Steer away from tie clip microphones - they usually have filters embedded to reject wind and handling noise, and have characteristics optimised for voice.

    In other respects, going for a battery...
  4. Replies
    1
    Views
    105

    Hi, I have ADAT gear and took a look at this a...

    Hi,

    I have ADAT gear and took a look at this a while ago. Output of ADAT turns out to be far simpler than input.

    Output starts be NRZI coding the data stream, which is a well documented...
  5. Replies
    6
    Views
    122

    A quick look at the SGTL data sheet (p30)...

    A quick look at the SGTL data sheet (p30) suggests that most, ifg not all of the enable/disable functions can be found in the CHIP_DIG_POWER register (0x0002).

    Simply set bits 0,1, 4,5,6 to zero. ...
  6. Replies
    166
    Views
    88,150

    Yes, moving to I2S2 might be a good idea - though...

    Yes, moving to I2S2 might be a good idea - though I'm not sure how much editing of the library routines might be required.

    Using the 6/8 channel board and TDM could produce the same result as...
  7. Replies
    166
    Views
    88,150

    Good to see the features we discussed in the...

    Good to see the features we discussed in the other (8 channel thread) being built into this 2 channel project.

    I'm based in Australia and OSH doesn't make much sense here either.

    I've been...
  8. Thread: Bat detector

    by palmerr
    Replies
    547
    Views
    44,284

    Hi, This invitation came in my email this...

    Hi,

    This invitation came in my email this morning, and I thought that they may be dealing with some issues similar to your bat detector.
    ...
  9. Just a thought... If you do have problems with...

    Just a thought... If you do have problems with crosstalk, try a piece of tinfoil to go in the gap, laminated with a copper wire (bad metallurgy there, so keep it dry!) stretched across it and...
  10. Replies
    9
    Views
    257

    Great that you have found a key to your puzzle. ...

    Great that you have found a key to your puzzle.

    I'm surprised to learn that a C0G produced that kind of response, though I might have expected it from a standard MLCC. All the available info...
  11. Replies
    9
    Views
    257

    Sounds like you're getting close to a good place...

    Sounds like you're getting close to a good place with the filters.

    My Focusrite shares the same characteristics - moderate input output impedances & HP filters - and I've been caught before.
    ...
  12. Replies
    9
    Views
    257

    Here's my board layout for the CS42448 and the...

    Here's my board layout for the CS42448 and the bottom copper - you can see a U shaped audio groundplane, with the digital one under the Teensy and reaching down under the chip. The two groundplanes...
  13. Replies
    9
    Views
    257

    Sorry about the misunderstanding. Assuming the...

    Sorry about the misunderstanding.

    Assuming the vias are going to a ground plane, the input and output layouts look OK.

    What's the impedance of your source? It will add to the 150 ohms on the...
  14. Replies
    9
    Views
    257

    I'm also working on a CS42448 board, however I've...

    I'm also working on a CS42448 board, however I've moved away from providing active input and output filters on the main board, due to parts count. Each 2 pole filter has around 9 components plus the...
  15. We'll be keen to see how it goes!

    We'll be keen to see how it goes!
  16. Many thanks. BCLK fixed now. Will republish...

    Many thanks. BCLK fixed now.

    Will republish in a few days after others have had a chance to comment.

    Hope to send of the boards for a prototype (board only) run for completion before Lunar New...
  17. I felt bad about saying the jumpers for T3 / T4...

    I felt bad about saying the jumpers for T3 / T4 could be a later addition.

    Updated schematics and layout attached, with T3/4 jumpers included.

    Please check my pinouts for both T3 & T4.
  18. Thanks for the bow tie suggestion - it's saved...

    Thanks for the bow tie suggestion - it's saved some real estate and allowed "normal" operation OOB on the inputs and outputs.

    While, I'm not trying for T3 / T4 compatibility on this iteration...
  19. Neat idea - I hadn't thought of using Teensy's...

    Neat idea - I hadn't thought of using Teensy's USB as ext pwr - simplifies that things a bit, and we're unlikely to get anywhere near the 1A limit (or even 500mA) of a phone charger.

    As for the...
  20. Thanks Mhelin for the commentary, I'll check...

    Thanks Mhelin for the commentary,

    I'll check the pinouts on the Teensy again. I must admit they are amongst the easiest things to fix - I've been concentrating on the audio ins and outs which are...
  21. As promised here is a first cut of the schematic...

    As promised here is a first cut of the schematic and broad layout.

    None of the components are optimised at this stage, and the decoupling caps are still sitting in a neat row at the bottom. Most...
  22. Gavin, Best wishes for your conversion...

    Gavin,

    Best wishes for your conversion project.

    I'm working on a T4 update to the CS42448 board at the moment, but it's still at the drawing board stage - and a topic of a separate stream in...
  23. Yes, the trade-offs in both BOM and board size...

    Yes, the trade-offs in both BOM and board size are important. I'm heading toward on board single pole filters, as the Audio Library's 16 bit depth gives a best case dynamic range of 78dB, and the...
  24. Yep, looks like someone else with sharper eyes...

    Yep, looks like someone else with sharper eyes picked up an issue I got wrong.


    Yes, unconnected inputs can create problems that are hard to track.


    Yes, there are multiple schools of thought...
  25. I have had a look at your schematics and the pin...

    I have had a look at your schematics and the pin assignments look fine (you've avoided the TX/RX assignment error on the published T4 Audio Board schematic).


    Having had a quick look at your...
  26. The discussion about the Eurorack requirements...

    The discussion about the Eurorack requirements has been enlightening - as I don't play on that side of the fence, and your bare-bones breakout board approach makes a lot of sense to allow for...
  27. useful thoughts. I'll definitely be sharing the...

    useful thoughts. I'll definitely be sharing the final product, rather than producing them to sell, and the modular approach, particularly for inputs makes sense. your "super long Teensy" approach...
  28. Paul, A further question - it appears from...

    Paul,

    A further question - it appears from tracing the Gerber file tracks on CS42446 OSHPark board, that the first of each pair of inputs goes to the tip of a 3.5 mm jack, whereas the first output...
  29. Yes, SMD can be a bit daunting. I'm currently...

    Yes, SMD can be a bit daunting.

    I'm currently working on a T4 rework of the CS42448 board, with better I/O filtering and I'm already up to 80 tiny little components and a 64pin LQFP to contend...
  30. I'm not quite sure what you're getting at with...

    I'm not quite sure what you're getting at with "HW configuration mode for the converters" - is it that some converters (e.g. CS5351) that could be used for adding extra channels via the the AUX...
  31. Paul, Thanks for the modular synth ideas. The...

    Paul,

    Thanks for the modular synth ideas. The overhead - extra supplies, DC coupling/offset, is probably more than I have real estate/energy for at this stage - at least to fully execute. What I...
  32. FYI, TDK has a daisy-chainable MEMS TDM...

    FYI,

    TDK has a daisy-chainable MEMS TDM microphone the ICS-52000 ($5 ea at Mouser).

    https://www.invensense.com/download-pdf/ics-52000-data-sheet/

    Up to 16 of them can be daisy-chained into a...
  33. Thanks for all the suggestions there - I'll...

    Thanks for all the suggestions there - I'll respond to a few of them, and bank the rest for future consideration.

    Writing the drivers is hard work, particularly when you need to ensure that they...
  34. CS42448 board update for T4 pinouts and improved performance

    Hi all,

    I'm starting work on an update to the CS42448 6 in/8 out board for the T4 pinouts - similar to the "Rev D" version of the SGTL5000 board Paul has recently published. It will go up on...
  35. Replies
    1
    Views
    134

    Hi, there are many suitable preamp modules...

    Hi,

    there are many suitable preamp modules available on eBay that will do the trick. most need a 12 v supply.

    The AD828 based ones might do the trick, as they will run on 5v. Beware, though...
  36. Replies
    0
    Views
    131

    Ethernet audio library ready to beta test

    Hi,

    I've been working on an Ethernet transport layer for the Audio library which is now ready for beta testing.

    https://github.com/palmerr23/EtherAudio - this repo only contains the...
  37. Soft limiter code available...

    If you want it, I have working soft limiter/compressor code that works on a T3.5.

    It is designed to drive an external gain cell, but the logic for hard and soft knees, gain ratios, attack and...
  38. Thanks. I hadn't thought of that approach - I...

    Thanks.

    I hadn't thought of that approach - I learnt my C in the late 70's (porting Unix kernels) and have had to add the ++ later in life, so I sometimes I miss something basic in OO.
  39. Using AudioStream::allocate() from AudioControl objects

    Hi,

    I'm working on an ethernet transport layer for the audio library - I have the basics working: input, output and control objects on T3.6 and T4.0 using Wiznet5500 modules. So far, I have tested...
  40. Replies
    81
    Views
    7,813

    I'll also have 3 spares of Paul's T4 BoB design...

    I'll also have 3 spares of Paul's T4 BoB design in a week or two - I ordered a run last week from China.
  41. Replies
    81
    Views
    7,813

    I've created an Eagle library with all the bottom...

    I've created an Eagle library with all the bottom pads in place.

    It's based on mng-25's.

    https://github.com/palmerr23/t4-eagle-full
  42. Replies
    5
    Views
    321

    bi-directional causes problems if you need...

    bi-directional causes problems if you need synchronised audio. even though the two clocks are crystal locked, they will drift over time. the usual solution is to use a master clock, usually generated...
  43. Replies
    9
    Views
    410

    here's another tip from the NXP community forum ....

    here's another tip from the NXP community forum . it's about an external SAI clocks on an iMXRT7D board, but might give you a lead.

    https://community.nxp.com/thread/480390
  44. Replies
    9
    Views
    410

    Mike My bad - I used MCLK when I meant master...

    Mike

    My bad - I used MCLK when I meant master clock - which confused everything!

    There are a few hints in https://www.nxp.com/docs/en/application-note/AN12090.pdf but not enough to complete the...
  45. Replies
    9
    Views
    410

    Mike Sorry I can't help with the clock timing,...

    Mike

    Sorry I can't help with the clock timing, but solving this problem will help with some other unresolved issues in the audio library/design tool - i.e. clock syncing with i2sslave. Have you...
  46. Replying to dslocum's post - that I can't see in...

    Replying to dslocum's post - that I can't see in this chain.

    The pin assignments are in the Adafruit_ILI9486_STM32.h file

    //Control pins |RS |CS |RST|
    #define TFT_CNTRL GPIOA
    #define...
  47. They're all in the Adafruit_GFX library.

    They're all in the Adafruit_GFX library.
  48. Replies
    46
    Views
    12,182

    Paul, Seems to work OK. No need for "verbose"...

    Paul,

    Seems to work OK. No need for "verbose" to be on any more.

    Richard
  49. Replies
    46
    Views
    12,182

    I've found that my 3.2 programs fine from the...

    I've found that my 3.2 programs fine from the Arduino IDE in Verbose mode under the new Win 10.

    Otherwise it needs to have a"button push".

    Considering the number of status requests generated...
  50. I'm not sure if you have solved your problem yet...

    I'm not sure if you have solved your problem yet with the 3.5" RPi screen.

    I have one and have it working.

    The chip is an ILI9486
    The interface is 16 bit serial - it resembles notro's circuit...
Results 1 to 50 of 63
Page 1 of 2 1 2