Open-source USB interface: Audio Widget

[alexlee188]

Originally Posted by Dendri

audio_widget_20121004_AB-1.2 I regret having updated

Not to worry. If all your attempts fail you can still try:

1. flash the firmware with Linux. If you are a Linux user (or can find a friend who is a Linux user), There are experienced Linux users in this thread to guide you to flashing under Linux.

2. If 1 fails, you will need jtag-ice MkII flashing.

Alex

[UnixMan]

Originally Posted by borges

Do you know if those older MACs support _asynchronous_ UAC1?

Oh! Good question: I don't know.

(not a Mac user myself...).

Maybe some info can be found here: "Technical Note TN2274 - USB Audio on the Mac".

See also: "Asynchronous OUT endpoint with rate feedback?" (it looks like some source code for OS/X have been made available).

[starn02]

An off topic question to Alex and Borges ....

Do you know if the I2C code in the firmware is working?
I'm trying to use it to access an LCD but while the writes are OK the READS are not working in my case ... in detail the addressed chip does not issue the requested ACK after the repeated start in the READ command (and the rest of the waveform is OK ...)
I see that the code is based on Atmel asf 1.6, and I know (having searched a lot on internet) that in that version the TWIM code was buggy .... what about the code in the firmware? Is it the same as in the SDR widget (where I suppose I2C is heavily used?)
Regards.

[alexlee188]

Starn02,

The i2c code is identical between sdr-widget and Audio-Widget.

The TWIM library from atmel has been modified for our use. Bugs were fixed and we enabled both ports.

Alex

[tdtsai]

As I know Mac OSX 10.4.x and later version all can support UAC 1.0 Asynchronous out endpoint.

Originally Posted by UnixMan

Oh! Good question: I don't know.

(not a Mac user myself...).

Maybe some info can be found here: "Technical Note TN2274 - USB Audio on the Mac".

See also: "Asynchronous OUT endpoint with rate feedback?" (it looks like some source code for OS/X have been made available).

[dhbiker]

so.....

my AB-1.2 just failed on me

first two pins on J5 show 0V, J4 also no voltage whatsoever. J2002 and J3002 fluctuate from 1.6 to 1.8V and J3, J8 show no voltage too...

any clues ?

yesterday i disconnected it and today i connected it... NADA

thanks for your reply

[1audio]

First check the cable and the host (and the connectors). The cables and connectors can be pretty fragile. Make sure the port is OK. There are circuit breakers that would give the impression of a high resistance source at the USB host.

[dhbiker]

good guess on the port... seems like i'll have to replace it with a new one

thank you very much

[lxiaob]

The I2S of my DAC shows DATA/LRCK/BCK/MCLK, what's pins on the USB-I2S board I should use to connect to the DAC?

[borges]

Originally Posted by lxiaob

The I2S of my DAC shows DATA/LRCK/BCK/MCLK, what's pins on the USB-I2S board I should use to connect to the DAC?

DATA: DA_SDATA TP58
LRCK: DA_LRCK TP59
BCK: DA_SCLK TP56

MCLK is trickier. The common variety of the USB-I2S module does not supply MCLK. Instead, your DAC board must generate it and send it to the module. (It may be that you have a module with XOs on it. In that case ignore the text below and tap MCLK from TP34.)

1) Provide 11.2896MHz on TP34 and 12.288MHz on TP36.

2) When TP32 (MCLK_P48_N441) is '1', provide 12.288MHz on TP34 and TP36, when TP32 is '0', provide 11.2896MHz on TP34 and TP36. This is how the AB-1.2 is set up.

I'm sure you'd like the XOs to be on the module at this point. BUT: any DAC will perform better when the XOs are close to the converter chip and running off a clean supply under your control. The module does have room for XOs but they run from the same 3.3V supply as the MCU.

Good luck with your DAC design!


Børge