libuarte+freertos receive wrong data

RE: libuarte+freertos receive wrong data

Lurn_Z — Thu, 02 Mar 2023 03:18:29 GMT

Ok, now, when I sending data by uarte, something went wrong.

you can see that, when I send 5A 0C 03 01 01 over uart for test, I can receive it correctly. then I modify the data in data[3] and data[4], the RTT print is OK, but the uart print is wrong. when i increase the data length, I found that the data from data[3] to data[31] are all 0.

Any idea what the problem could be?

BR,

Lurn

RE: libuarte+freertos receive wrong data

Lurn_Z — Wed, 01 Mar 2023 03:43:45 GMT

Hi Kenneth,

I think this problem has been solved.

I modified the buffer size, buffer number and time_out to find the values that work for me.

Now, it is running ok.

Thanks a lot!

BR,

Lurn

RE: libuarte+freertos receive wrong data

Lurn_Z — Tue, 28 Feb 2023 15:24:10 GMT

Sorry, I haven't measured it...

RE: libuarte+freertos receive wrong data

Kenneth — Tue, 28 Feb 2023 11:51:24 GMT

Out of curiosity, have you measured how long time your "UART_PRINTF("data_array = %s", data_array);" takes?

Best regards,
Kenneth

RE: libuarte+freertos receive wrong data

Lurn_Z — Tue, 28 Feb 2023 11:33:27 GMT

OK,

NRF_LIBUARTE_ASYNC_DEFINE(_name, _uarte_idx, _timer0_idx,\
_rtc1_idx, _timer1_idx,\
_rx_buf_size, _rx_buf_cnt);

So, how many _rx_buf_cnt can i set at most?

and what is the maximum _rx_buf_size I can set?

BR,

Lurn

RE: libuarte+freertos receive wrong data

Kenneth — Tue, 28 Feb 2023 10:20:22 GMT

Hi,

It's quite normal in any communication that data is fragmented, how you solve this is up to your requirements, but I can only confirm that what you observe is normal.

Please have in mind that if you are also outputting the data to a log here, that may likely impact the throughput.

Best regards,
Kenneth

RE: libuarte+freertos receive wrong data

Lurn_Z — Tue, 28 Feb 2023 09:42:53 GMT

So, after my test, I send 32 bytes, the data head is A5 C5, and print 34 bytes so the last two data should be 0 (uint8_t data_array[256] = {0};).

Here is 3 questions.

1. When the sender sending data slowly, about 25 times per second, logs looks like that.

After receiving several pieces of data, one of it was split into two parts

2. When the sender sending data quickly, (250 times per second), data will be lost, Only 30 pieces of data are received per second.

3. When the sender sending data quickly, (250 times per second), logs looks like that.

There is an exception in the data format,

Hope you can give me some suggestions.

If you need my application, please tell me.

BR,

Lurn

RE: libuarte+freertos receive wrong data

Lurn_Z — Tue, 28 Feb 2023 01:59:16 GMT

Hi Kenneth,

I saw this link, and from my understanding of this question is when I want send n bytes, I need packet it and send 2*n+1 bytes?

if my understanding is correct, I can't use it. cause my nrf device just receiver, the sender is another device that I can not control it.

And I think this question maybe about the rx buffer, because when I change the RX buffer from 256 to 64, the data was be split earlier.

NRF_LIBUARTE_ASYNC_DEFINE(libuarte, 0, 0, 0, NRF_LIBUARTE_PERIPHERAL_NOT_USED, 64, 3);

Do you have any other solution?

And I have another question that I need a frequency of 500 times per second, but when I test the application,I don't think it can reach this frequency. Because I get the logs in 9 second, it just 260 times data. Also I will check the sender frequency, and hope you can give me some suggestions.

BR,

Lurn

RE: libuarte+freertos receive wrong data

Kenneth — Mon, 27 Feb 2023 22:47:22 GMT

[quote user="Lurn_Z"]How should I do this?[/quote]

Or maybe you could do it much simpler.

Maybe you could do as the SLIP packet framing as described in the Bluetooth Core Specification 4.0, Volume 4, Part D, Chapter 3 SLIP Layer.

SLIP framing ensures that all packets sent on the UART are framed as:
<0xC0> SLIP packet 1 <0xC0>
<0xC0> SLIP packet 2 <0xC0>

In your case replace "SLIP packet" with "your packet".

Kenneth

RE: libuarte+freertos receive wrong data

Lurn_Z — Mon, 27 Feb 2023 16:07:01 GMT

Hi Kenneth,

[quote userid="2111" url="~/f/nordic-q-a/97108/libuarte-freertos-receive-wrong-data/412240"] So you may need to add some header, length field and checksum to handle fragmentation in the application. [/quote]

How should I do this?

[quote userid="2111" url="~/f/nordic-q-a/97108/libuarte-freertos-receive-wrong-data/412240"]Though, you may try to increase the timeout_us also to see if that helps (e.g. try 200us instead of 100us).[/quote]

I modify the time out to 10/1000, it looks like same.

BR,

Lurn

RE: libuarte+freertos receive wrong data

Kenneth — Mon, 27 Feb 2023 11:38:39 GMT

Hi,

Packets may be fragmented depending on buffer alignment and timeout. So you may need to add some header, length field and checksum to handle fragmentation in the application. Though, you may try to increase the timeout_us also to see if that helps (e.g. try 200us instead of 100us).

Kenneth