12.5k Sampling ADC Data lost

RE: 12.5k Sampling ADC Data lost

odenwar — Thu, 01 Apr 2021 09:08:14 GMT

I've checked.
There was a baud rate setting in the main code.
I thought I had to modify it in the sdk_config.h file, but I need to do it in the main.

static void uart_init(void)
{
    uint32_t                     err_code;
    app_uart_comm_params_t const comm_params =
    {
        .rx_pin_no    = RX_PIN_NUMBER,
        .tx_pin_no    = TX_PIN_NUMBER,
        .rts_pin_no   = RTS_PIN_NUMBER,
        .cts_pin_no   = CTS_PIN_NUMBER,
        .flow_control = APP_UART_FLOW_CONTROL_DISABLED,
        .use_parity   = false,
#if defined (UART_PRESENT)
        .baud_rate    = NRF_UART_BAUDRATE_1000000
#else
        .baud_rate    = NRF_UARTE_BAUDRATE_115200
#endif
    };

    APP_UART_FIFO_INIT(&comm_params,
                       UART_RX_BUF_SIZE,
                       UART_TX_BUF_SIZE,
                       uart_event_handle,
                       APP_IRQ_PRIORITY_LOWEST,
                       err_code);
    APP_ERROR_CHECK(err_code);
}

RE: 12.5k Sampling ADC Data lost

odenwar — Wed, 31 Mar 2021 15:04:33 GMT

I'll check the RTT, but I think it should work in the UART specification.

Uart baud rate 1,000,000

12.5k [ Sampling Data Count ] * ( 8 [ Character bit ] * 6 [ Actual data including newline characters ] )

= 600,000

The share of the spec is using 60%.
Looks fine.

RE: 12.5k Sampling ADC Data lost

Vidar Berg — Wed, 31 Mar 2021 14:48:08 GMT

You can read more about Segger RTT here: https://www.segger.com/products/debug-probes/j-link/technology/about-real-time-transfer/. It basically allows you to log data out on the SWD/Debug interface instead of using UART.

sdk_config.h settings to enable the RTT Logger module backend:

NRF_LOG_BACKEND_UART_ENABLED 0

NRF_LOG_BACKEND_RTT_ENABLED 1

And RTT log displayed in "Debug Terminal":

RE: 12.5k Sampling ADC Data lost

odenwar — Wed, 31 Mar 2021 13:57:36 GMT

what do you mean?

"Is it an option to use RTT for logging instead? It should be faster."

RE: 12.5k Sampling ADC Data lost

Vidar Berg — Wed, 31 Mar 2021 13:25:13 GMT

Hello,

I'm not seeing any mistakes in the code you posted, it looks like you are just sending more data than what the UART can handle. Is it an option to use RTT for logging instead? It should be faster.

Best regards,

Vidar