UART high speed issue - ZEPHYR rtos

RE: UART high speed issue - ZEPHYR rtos

qwertynoon — Thu, 24 Feb 2022 12:38:45 GMT

ok!!! done!!! all works fine!!!! Thank you very much.

RE: UART high speed issue - ZEPHYR rtos

qwertynoon — Wed, 23 Feb 2022 21:10:35 GMT

Thanks. It works!!! But how can I keep system from FAULT when I send a big packet to nrf52840,

When I send a very big packet of bytes it causes a fault

ASSERTION FAIL [err == 0] @ WEST_TOPDIR/nrf/samples/peripheral/lpuart/src/main.c:70
        Failed to provide new buffer
[00:01:22.163,604] <inf> app: Received data 27 bytes
[00:01:22.171,356] <inf> app: UART_RX_BUF_RELEASED
[00:01:22.171,417] <inf> app: Received data 64 bytes
[00:01:22.189,208] <inf> app: UART_RX_BUF_RELEASED
[00:01:22.189,270] <inf> app: Received data 64 bytes
[00:01:22.207,092] <inf> app: UART_RX_BUF_REQUEST
[00:01:22.207,183] <inf> app: UART_RX_BUF_RELEASED
[00:01:22.207,214] <inf> app: UART_RX_BUF_RELEASED
[00:01:22.207,275] <inf> app: UART_RX_BUF_REQUEST
[00:01:22.217,773] <err> os: r0/a1:  0x00000004  r1/a2:  0x00000046  r2/a3:  0x00000001
[00:01:22.217,803] <err> os: r3/a4:  0x0000001e r12/ip:  0x00000000 r14/lr:  0x000007af
[00:01:22.217,864] <err> os:  xpsr:  0x41000038
[00:01:22.217,895] <err> os: Faulting instruction address (r15/pc): 0x0000fa2c
[00:01:22.217,895] <err> os: >>> ZEPHYR FATAL ERROR 4: Kernel panic on CPU 0
[00:01:22.217,926] <err> os: Fault during interrupt handling

[00:01:22.217,926] <err> os: Current thread: 0x20000490 (unknown)
[00:01:22.321,929] <err> os: Halting system

I tried to increase buffer size but no result

#define BUF_SIZE 500
static K_MEM_SLAB_DEFINE(uart_slab, BUF_SIZE, 3, 4);

RE: UART high speed issue - ZEPHYR rtos

Simon — Wed, 23 Feb 2022 10:03:39 GMT

The lpuart sample uses flow control (with GPIOs (req and rdy) instead of UARTS rts and cts), so I guess it will not work if the device (ESP8266 ) you're communicating with does not have flow control. Check out the patch I provided that shows how to disable flow control: https://github.com/nrfconnect/sdk-nrf/compare/v1.6.0...simon-iversen:lpuart_using_normal_uart

RE: UART high speed issue - ZEPHYR rtos

qwertynoon — Wed, 23 Feb 2022 09:46:48 GMT

Thanks for your reply.

I have tested lpuart sample and RX handle is pretty good for me, but TX is not working

It wait for 10 seconds (timeout) and then ASSERT print an error "TX aborted"

I tried to change state of this pins

req-pin = <22>; rdy-pin = <23>;

but no success

RE: UART high speed issue - ZEPHYR rtos

Simon — Tue, 22 Feb 2022 13:02:59 GMT

Could you test the lpuart sample and see if that works better? Here is the modifications I did to the sample to make it work without flow control: https://github.com/nrfconnect/sdk-nrf/compare/v1.6.0...simon-iversen:lpuart_using_normal_uart

Best regards,

Simon

RE: UART high speed issue - ZEPHYR rtos

qwertynoon — Fri, 18 Feb 2022 07:04:09 GMT

Thanks for reply, Simon.

All works fine if incoming data length == UART_BUF_SIZE

For example if I send 200 bytes and UART_BUF_SIZE = 200 then all ok.

But if incoming length < 200 then I cant free buffer and then catch "no free memory for allocate rx buffer"

Unfortunaly I cant use example uart implementation completely because I need to handle uart buffer without "\n\r" only by timout (my packet dont consist cr_lf)

P.S. There is no free pins ESP8266 and I think flow control will not fix the issue

RE: UART high speed issue - ZEPHYR rtos

Simon — Fri, 18 Feb 2022 00:08:17 GMT

It may be that you're not able to handle the incoming data fast enough, you could look into that. Maybe you could upload the sample as a zipped file, and I can see if I can reproduce it.

You could also try to enable flow control in an .overlay file, similar to how it's done here: https://github.com/nrfconnect/sdk-zephyr/blob/v2.7.99-ncs1/samples/bluetooth/hci_uart/boards/nrf52840dk_nrf52840.overlay#L7. Then check the file <sample>\build\zephyr\zephyr.dts what rts-pin and cts-pin are for uart0 and connect the nRF52840 to the ESP8266 accordlngly.

Best regards,

Simon