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no audio input in USB Audio
Posted: Wed Aug 20, 2014 4:33 pm
by Unchyu2
Hello,
I am trying to implement the code in "USB-Audio-2.0-Device-Reference-Design-Software(6.6.0)" for my USB sliceKit (XP-XKC-U16 1v2) and my audio slice (XA-SK-AUDIO 1v1). To do this I have programmed the board with the following application "app_usb_aud_skc_u16".
I can successfully listen to music played from my PC but I cant get any input going into it.
Using an oscilloscope I have probed the I2S data signal coming from the ADC and it looks fine, therefore I think the problem is that XMOS is not sending the signal over USB.
I have also checked if the problem was with the USB audio driver by connecting the sliceKit to a Mac computer, ho still hadn't any input, therefore I don't think that's the problem.
Any help is most welcomed.
Re: no audio input in USB Audio
Posted: Thu Aug 21, 2014 9:45 am
by Ross
app_usb_aud_skc_u16 can be build with many configurations, ensure you are running one that has input enabled (2ioxx for example). The configuration naming scheme can be found in the USB Audio Design Guide.
Also, make sure the jumpers on the board are set to that specified in the readme file in the app_usb_aud_skc_u16 folder.
Re: no audio input in USB Audio
Posted: Thu Aug 21, 2014 10:02 am
by Unchyu2
thank you for your reply Ross
app_usb_aud_skc_u16 has only one configuration in it's makefile:
Code: Select all
# The flags passed to xcc when building the application
BUILD_FLAGS = -DFLASH_MAX_UPGRADE_SIZE=64*1024 -fcomment-asm -Xmapper --map -Xmapper MAPFILE -Wall -O3 -report -lflash -fsubword-select -save-temps -g -fxscope -DXSCOPE -DSDA_HIGH=2 -DSCL_HIGH=1 -DXUD_ON_U_SERIES=1
# Test build configs (Note these make use of the defaults in customdefines.h)
# Audio Class 2, Input, Output, No MIDI, SPDIF
XCC_FLAGS_2ioxs = $(BUILD_FLAGS)
INCLUDE_ONLY_IN_2ioxs =
and according to USB Audio Design Guide, it should have input and output enable
and my jumpers are set accordingly; J14 to ALT and J15 to ON
Re: no audio input in USB Audio
Posted: Thu Aug 21, 2014 12:33 pm
by Ross
What signal are you driving into the ADC and what program are you using to try and record?
Re: no audio input in USB Audio
Posted: Thu Aug 21, 2014 1:13 pm
by Unchyu2
Audio signal coming from a cellphone jack output.
To record I am using Ableton Live, I have configured the audio device in preferences to use :driver type - ASIO, and audio device - TUSBAudio ASIO Driver. I can see the XMOS slice kit as a sound card with 4 in's and 4 out's in Ableton but I don't get any input from it.
If I change NUM_USB_CHAN_IN or NUM_USB_CHAN_OUT in customdefines.h, Ableton (or the TUSBAudio driver) sees the changes and configures the IN/OUT ports accordingly.
My main problem is that I dont have any signal at recording devices
Re: no audio input in USB Audio
Posted: Fri Aug 22, 2014 5:44 am
by Bayanaa
I also had same problem that you showed in Figure. But I had solved it :)) . Did you compile original source code or add new source code (i.e, dsp) ?
Re: no audio input in USB Audio
Posted: Fri Aug 22, 2014 9:16 am
by Unchyu2
I compiled the original code without any alteration.
I have even re-downloaded the "USB-Audio-2.0-Device-Software(6.6.0)" reference design from xmos website, created a new project and re-compiled the application, and still no luck.
Re: no audio input in USB Audio
Posted: Mon Aug 25, 2014 2:29 pm
by Unchyu2
So, after one week of troubleshooting I discovered that you have to connect with a wire the signal from PORT_MCLK_IN2 (aka PIN X0D13) to PORT_MCLK_IN (aka PIN X1D12) on the sliceKit (XP-SKC-U16 1v2)
Re: no audio input in USB Audio
Posted: Tue Aug 26, 2014 10:19 am
by Ross
Unchyu2 wrote:So, after one week of troubleshooting I discovered that you have to connect with a wire the signal from PORT_MCLK_IN2 (aka PIN X0D13) to PORT_MCLK_IN (aka PIN X1D12) on the sliceKit (XP-SKC-U16 1v2)
This is not required, the jumper marked D12 XOVER should do this for you (J15)
Re: no audio input in USB Audio
Posted: Wed Aug 27, 2014 3:07 pm
by Unchyu2
as I said earlier, with the jumper set on "ON" position I couldn't receive any audio into my PC.
With the jumper on "ON" & the external wire I can record audio throw USB.