Open-source USB interface: Audio Widget

[borges]

Hi Turbon,

the AB-1.12 will be a naked board for analog prototyping. In order to do anything with it you'll have to populate it with whatever feature you wish to prototype. Then you need to plug in an existing USB-I2S module.

The AB-1.12 will fit in the same enclosure as the AB-1.1. The board is only an add-on to the AB-1.1 with features not yet tested.

The PCM5102 is already designed in. Right now I'm working on the new suggested regulators. It's hard to tell exactly when I'll be done with it.


Børge

[Turbon]

Originally Posted by borges

Hi Turbon,

the AB-1.12 will be a naked board for analog prototyping. In order to do anything with it you'll have to populate it with whatever feature you wish to prototype. Then you need to plug in an existing USB-I2S module.

The AB-1.12 will fit in the same enclosure as the AB-1.1. The board is only an add-on to the AB-1.1 with features not yet tested.

The PCM5102 is already designed in. Right now I'm working on the new suggested regulators. It's hard to tell exactly when I'll be done with it.


Børge

OK, thanks Börge!

Looking forward to the naked board... Are the DAC's pin compatible or what kind of solution do you have in mind? I might have a different interpretation of the meaning of an "add-on" - should I keep the AB-1.1 and wire an add on board in the old DAC's place or will the new board replace the whole AB-1.1 board? What about a new DAC - should I then replace the AB-1.2 with the AB-1.3 board if a new DAC is invited to the widget world? Shurely there must be a way to disminish the cost by the way of an modularized approach.

Brgds

[borges]

Yes, cost is reduced because you recycle the module and the box you already bought from me :-)

The AB-1.12 will only be an analog board. Since the two XOs are custom components I'll probably ship them with the naked board so that you don't have to strip components off what you already have. The remaining components should be easily obtained and depend on what you want to implement on the proto.


Børge

[Turbon]

Will it be on its own board on AB-1.2?
As I see it 1.2 should be the splitpoint in time where the AB becomes really analog carving out the DAC to a board to itself.

Brgds

[Onvinyl]

Suddenly, I'm having those already mentioned rate-change issues as well.
This is my stream0 when mpd changes from a 16/44.1 to a 24/96 wav-file:

www.obdev.at DG8SAQ-I2C at usb-0000:00:13.2-2, high speed : USB Audio

Playback:
  Status: Running
    Interface = 2
    Altset = 1
    URBs = 8 [ 8 8 8 8 8 8 8 8 ]
    Packet Size = 392
    Momentary freq = 181492 Hz (0x16.afc0)
    Feedback Format = 16.16
  Interface 2
    Altset 1
    Format: S32_LE
    Channels: 2
    Endpoint: 2 OUT (ASYNC)
    Rates: 44100, 88200, 132300, 176400, 48000, 96000, 144000, 192000
    Data packet interval: 250 us

Is there a comprehensive how-to how to deal with firmware updates? Are they possible on a linux shell (x-less system) or must/should I plug the widget in a windows machine?

Rüdiger

[alexlee188]

Hi Onvinyl,

What version of firmware are you using?

For Linux and mpd, you need:

audio-widget-nik-2012-01-27.elf - sdr-widget - Unified firmware for audio-widget. For Linux alsa uac2 driver and mpd playback only May not work properly under Win or OSX. - Audio and Control Interface for Amateur Radio SDR and Audiophile USB-DAC - Go

The instructions to flash firmware (Linux and Windows) is in:

Programming widget firmware.txt - sdr-widget - Instructions for programming (flashing) the widget firmware - Audio and Control Interface for Amateur Radio SDR and Audiophile USB-DAC - Google Project Hosting

If you want to use command line Linux to flash, build this program:

dfu-programmer-0.5.4.tar.gz - sdr-widget - Hacked dfu-programmer to workaround "User Page" problem. - Audio and Control Interface for Amateur Radio SDR and Audiophile USB-DAC - Google Project Hosting

Alex

[Onvinyl]

Thanks Alex, I'll wade through this.
How can I read-out the firmware version?

lsusb gives e.g.

  iManufacturer           1 www.obdev.at
  iProduct                2 DG8SAQ-I2C
  iSerial                 3 1.0.0.0.0.0.A

Rüdiger

[borges]

Here is a draft sch and layout for the regulator which has been discussed here lately. Any comments?

I plan to put 3 such regulators on the AB-1.12 prototype board. The regulators will not be connected to other circuitry. It will be easy to patch them into points of load at the two XOs and at the DAC.

Børge

[Onvinyl]

Hi Børge,

are these regs intended to run from dedicated PSUs or are they intermediate stages between usb-power and DAC/XO?

Rüdiger

[borges]

Both! The digital parts run from the 3.3V LDO on the module. That will include the MCLK divider whos only purpose is to synchronize the MCU.

Børge