NCS NUS example - bigger buffer

RE: NCS NUS example - bigger buffer

Vojislav — Mon, 08 Jun 2020 17:16:59 GMT

I figured it out, thanks for all the help!

Best regards,
Vojislav

RE: NCS NUS example - bigger buffer

Vojislav — Mon, 08 Jun 2020 12:07:02 GMT

issue1 (peripheral > central):

[quote userid="80703" url="~/f/nordic-q-a/62119/ncs-nus-example---bigger-buffer/253760"]Not able to allocate UART send data buffer[/quote]

Data is received and then this message is sent from the central device to PC.

issue2 (central > peripheral):

[quote userid="80703" url="~/f/nordic-q-a/62119/ncs-nus-example---bigger-buffer/253773"]NUS send timeout
Failed to send data over BLE connection (err -69)[/quote]

This is how sending data looks:

* time between data packets is ~9ms, and each block is 127bytes
it seems that UART is sending data too quickly and BLE NUS does not have time to send it.

RE: NCS NUS example - bigger buffer

Vojislav — Mon, 08 Jun 2020 11:48:32 GMT

and also:

NUS send timeout
Failed to send data over BLE connection (err -69)

RE: NCS NUS example - bigger buffer

Vojislav — Mon, 08 Jun 2020 11:18:08 GMT

Hi Simon,

This seems to work, but sometimes I get BLE timeout message or "Not able to allocate UART send data buffer"

Did you have similar problems?

Best regards,
Vojislav.

RE: NCS NUS example - bigger buffer

Simon — Sat, 06 Jun 2020 16:02:49 GMT

I was able to send 1000 bytes by doing the following:

In ncs\nrf\samples\bluetooth\central_uart\prj.conf set these:

CONFIG_BT_L2CAP_TX_MTU=1024
CONFIG_BT_L2CAP_RX_MTU=1024
CONFIG_BT_RX_BUF_LEN=1024

In ncs\nrf\samples\bluetooth\peripheral_uart\prj.conf set these:

CONFIG_BT_GATT_NUS_UART_BUFFER_SIZE=1024
CONFIG_BT_RX_BUF_LEN=1024
CONFIG_BT_L2CAP_TX_MTU=1024
CONFIG_BT_L2CAP_RX_MTU=1024

In in ncs\zephyr\subsys\bluetooth\host\att_internal.h, set BT_ATT_DEFAULT_LE_MTU to 1024
In ncs\nrf\samples\bluetooth\central_uart\src\main.c set UART_BUF_SIZE to 1024

If you're going to send data chunks of size 1024, you may have to set the buffers a little bigger, due to overhead and so on.

Best regards,

Simon

RE: NCS NUS example - bigger buffer

Vojislav — Thu, 04 Jun 2020 11:05:13 GMT

So when I want to send a bigger data packet (with code changed in central application) I get a response:

E: ***** BUS FAULT *****␍␊
[13:03:07:755] E:   Precise data bus error␍␊
[13:03:07:755] E:   BFAR Address: 0x1000257␍␊
[13:03:07:761] E: r0/a1:  0x00000010  r1/a2:  0x01000257  r2/a3:  0x00001010␍␊
[13:03:07:761] E: r3/a4:  0x01000257 r12/ip:  0x00000003 r14/lr:  0x00002ec3␍␊
[13:03:07:769] E:  xpsr:  0x21000000␍␊
[13:03:07:769] E: Faulting instruction address (r15/pc): 0x00002ec4␍␊
[13:03:07:776] E: >>> ZEPHYR FATAL ERROR 0: CPU exception on CPU 0␍␊
[13:03:07:784] E: Current thread: 0x200010b4 (unknown)␍␊
[13:03:07:784] E: Resetting system␍␊