UART Framing error / communication error on nrf52820

RE: UART Framing error / communication error on nrf52820

Vidar Berg — Mon, 20 Sep 2021 08:52:57 GMT

Hi,

I recommend you use the Libuarte - advanced UARTE driver instead of the app uart library. The app uart library doesn't support large DMA buffers (only supports 1 byte) and it can be difficult to prevent data loss unless you include HW flow control.

[quote userid="94184" url="~/f/nordic-q-a/79813/uart-framing-error-communication-error-on-nrf52820/330193#330193"]for example, after we "turn off" APP_UART_COMMUNICATION_ERROR handler, if the uarte received a corrupted packet, the uarte still can go to "NRF_DRV_UART_EVT_RX_DONE" then put the receive data into fifo.[/quote]

Yes, but APP_UART_COMMUNICATION_ERROR means you have lost a packet due to an UARTE error condition.

RE: UART Framing error / communication error on nrf52820

David Duan — Mon, 20 Sep 2021 08:47:25 GMT

Hi Berg

Thanks for your reply.

we will try your suggestion.

Just a quick question at here.

do we have any setting to ignore or "turn off" the APP_UART_COMMUNICATION_ERROR handler?

for example, after we "turn off" APP_UART_COMMUNICATION_ERROR handler, if the uarte received a corrupted packet, the uarte still can go to "NRF_DRV_UART_EVT_RX_DONE" then put the receive data into fifo.

RE: UART Framing error / communication error on nrf52820

Vidar Berg — Mon, 20 Sep 2021 07:26:58 GMT

Hi,

[quote user=""]We have change the UARTE to libuarte, but this issue still happen.[/quote]

The code snippets you posted shows that you're calling the UARTE driver APIs directly, not libuarte. Is that the old code?

[quote user=""]The project only have BLE, RTC and UARTE, we set the uarte interrupt as the highest priority but the issue still happen.[/quote]

I would rather recommend that you increase the DMA buffers to offload the CPU more.

[quote user=""]1. since uarte and BLE both will use the hfclk, and the this issue only happen will 5 BLE connection(see figure 1).do we have some specical ceritaria for using function "sd_clock_hfclk_request()" ?[/quote]

Calling sd_clock_hflck_request() after ble_stack_init() is sufficient. This will make the SD keep the HFXO always on.

[quote user=""]

1. uart event error handler

we try to add the bleow code in UART error handler , but the issue still happen.

we want to know, when the error handler capture the APP_UART_COMMUNICATION_ERROR, does it means uarte RX data is incorrect?

[/quote]

Yes, APP_UART_COMMUNICATION_ERROR effectively means you recived a corrupted packet and that it is dropped/lost.

Best regards,

Vidar