AVB Point-to-Point with two XK-AVB-LC boards

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Joerg4u
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AVB Point-to-Point with two XK-AVB-LC boards

Post by Joerg4u »

Hello,

I am trying to get some AVB experiences. For this I have on my bench:

2x XK-AVB-LC Endpoint boards each with sw_avb_lc - 6.1.1rc1 inside

1x Raspberry PI with AVDECC Controller version: v0.5.0

1x Cisco Systems EZXS88W, a 8port none AVB 100MHz switch

xTIME Composer Studio (Community_14.0.4) on Win7

 

I put the Raspberry Pi and the two AVB endpoints into the none AVB switch and with the AVDECC Controller I have successfully established an audio connection from one AVB endpoint to the other. Without reset or repowering the both AVB endpoints, I removed the ethernet cables from the switch and made a point-to-point connection between the AVB endpoints. Well, I think you already expected this, there was a running audio connection between this two AVB-endpoints.

Now my question:

Is it possible for further measurements and presentation to have an easier, smaller hardware setup ? So that I can remove the Rasperry PI and the switch ? 

I am thinking about some reconfiguration of the sw_avb_lc demo.

 

Kind regards,

Joerg

 

 



srinie
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Joined: Thu Mar 20, 2014 8:04 am

Post by srinie »

Hi,

Yes, you can connect these `two` xmos end-points directly without the switch and a controller.

In avb_conf.h, enable the below macro on an end-point to execute this setup.

AVB_1722_1_CONTROLLER_ENABLED

Joerg4u
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Joined: Wed Jul 15, 2015 11:33 am
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Post by Joerg4u »

Thanks a lot. It works fine.  

chmedly
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Post by chmedly »

I'm trying this but not having luck. My two endpoints are not matched. One is the DSP4You AVB-DG board using what I believe is the sw_avb_lc - 6.1.1rc 1 example code. The other one is the Xmos multichannel audio board running the latest gigabit AVB endpoint example. I've tried enabling the CONTROLLER_ENABLED in the gigabit board and it does change the behavior somewhat. With this change the gigaboard appears to start streaming to the DG board. But it doesn't set itself up as a listener.

Here's the read out:

PTP Port 0 Role: Master
Setting clock source: INPUT_STREAM_DERIVED
PTP Port 0 Role: Master
Joined SRP domain (VID 2, port 0)
PTP Port 0 Role: Master
MAAP reserved Talker stream #0 address: 91:E0:F0:0:9D:E0
CONNECTING Talker stream #0 (229780D940000) -> Listener 0:50:C2:FF:FE:D4:36:28
MSRP: Register stream request 229780:D940000
Added stream:
ID: 229780D940000
DA:91:E0:F0:0:9D:E0:
max size: 800
interval: 1
MVRP: Joined VID 2
Talker stream #0 ready
Increasing port 0 shaper bandwidth to 53888000 bps
Talker stream #0 on


I've also had some trouble testing this. I don't yet have a separate AD or DA converter configured for connecting the the AVB-DG board so I just connected the I2S in1 to out1 pins so that incoming audio on inputs 1-2 will just go right back out on outputs 1-2. I'm not sure that this loopback technique is working as intended. The loopback does work when the DG board is connected to a MacOS computer except that it is way way too loud. I suspect it's a 16->24bit issue. If I turn the level on the sending app way way down it sounds clean and fine. It appears to me that this could be on the order of 48db of boost.
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