AWR2944EVM: LVDS-Eth Data Stuck Problem

Woody

Prodigy 60 points

Part Number: AWR2944EVM
Other Parts Discussed in Thread: AWR2944

Hello, now we had a problem that had been bothering us for a long time.

Background

we use PC, AWR2944EVM and DCA1000 to collect the radar data as following diagram:

the MMW and data sequence as following diagram:

The size of each data segment is shown as following form.

Session	SubSession	Size(byte)
HwSession	ADC data	1,572,864
SwSession	Dummy	5,440
	Detection list	56,784
	Userheader	1,456
Total		1,636,544

Tips: These data have aligned by 64bytes and 1456bytes

Problem

We collect the UDP packets from the DCA1000.

In theory, we should receive 1124 (1636544÷1456) UDP packets per 125ms, but only receive 390+ packets per 125ms actually (shown in the diagram).

So when we process these data, the result is not the expectation.

Our preliminary analysis is the AWR2944EVM occupy the DCA1000 too much time, so DCA1000 can't transmit the LVDS data timely.

Could you hlep us to find the root cause and solve this problem?

over 2 years ago

0 Saswat Kumar over 2 years ago

TI__Mastermind 35155 points

Hello Woody,

Could you confirm whether you are using mmwave studio or any custom application?
Also are you receiving all the data? Is there any loss of data?
Also how are you doing the calculation for how many packets per second?

Regards,
Woody

0 Woody over 2 years ago in reply to Saswat Kumar

Prodigy 60 points

1.I don't use any application,except Wireshark to collect the ethernet data.

2.Yes, I have received all the data, it looks like no data is lost. but the status is not stable,may be in 3 period send 300+ packets,and next period send 3500+ packet, so in this 4 period, the total packets number is right.

3.I calculate the packets according to the form shown in the above

0 Saswat Kumar over 2 years ago in reply to Woody

TI__Mastermind 35155 points

Hello woody,

So, are you writing a custom application? How is that you are configuring the AWR2944 and DCA1000?
Also, could you go through the DCA1000 user guide to understand the throughput of the device and the delays that might be occurring as well DCA1000EVM Data Capture Card User's Guide (Rev. A) (ti.com).

Regards,
Saswat Kumar

0 Woody over 2 years ago in reply to Saswat Kumar

Prodigy 60 points

Yes,we write a custom application,and flash it to the AWR2944EVM board by UART port.

we use the SDK code to config the AWR2944, and don't config DCA1000, just use the default configuration.

I have read the Guide you mentioned, and I will try to check the delays.

0 Saswat Kumar over 2 years ago in reply to Woody

TI__Mastermind 35155 points

Hello Woody,

Yes, do let me know once you have checked out the delays and if that's what is causing this issue.

Regards,
Saswat Kumar

0 Woody over 2 years ago in reply to Saswat Kumar

Prodigy 60 points

Hi Saswat Kumar，

By accident of adjusting data alignment from 64B to128B, it seems that the problem is solved, and the ethernet speed from DCA1000 is also stable.

+1 Saswat Kumar over 2 years ago in reply to Woody

TI__Mastermind 35155 points

Hello woody,

If this did solve your issue, then I will be closing the thread.
In case if you have any queries on this topic you can reopen it by replying to this thread, or else open a new thread based on a different problem.

Regards,
Saswat Kumar

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AWR2944EVM: LVDS-Eth Data Stuck Problem