Configuration UARTE with nrf52805 for ESB - Part 2

[Ilary]

My previous ticket is closed. I would need, but still help with the configuration of the pins. I report my last post.

Hello,
I did some tests with the oscilloscope directly connected to pins 21 and 18 of the nrf52805.
The transmission on pin 18 by the Stm8l works perfectly. The problem I encounter now is that nrf52805 I have the pull up instruction on this pin

 nrf_gpio_cfg_input(PIN_RXD,GPIO_PIN_CNF_PULL_Pullup);

but nothing happens when oscilloscopes.

It could be that I get the pin definition wrong initially

 #define UARTE_BASE           0x40002000
  #define PORTA_UARTE          ((NRF_UARTE_Type *) UARTE_BASE )
  #define PIN_TXD            21
  #define PIN_RXD            18

or the pull up configuration of pin 18, set as input and pin 21 as output?

 nrf_gpio_cfg_input(PIN_RXD,GPIO_PIN_CNF_PULL_Pullup);
     nrf_gpio_cfg_output(PIN_TXD);

[Sigurd]

Ilary said:

uart but returns as an event APP_UART_COMMUNICATION_ERROR

You should check the value of p_event->data.error_communication , the value in error_communication corresponds to the ERRORSRC register. 

Most likely OVERRUN . Try using flow-control , or try a different baudrate.

[Ilary]

thanks for the answer, I edited the baudrate from 115200 to 2400 on both nrf52805 and STM8 but I still received the error, I have at this point enabled flow control with the code

static void uart_init(void)
{
    uint32_t                     err_code;
    app_uart_comm_params_t const comm_params =
    {
        .rx_pin_no    = PORTA_RXD,
        .tx_pin_no    = PORTA_TXD,
        
        .flow_control = APP_UART_FLOW_CONTROL_ENABLED,
        .use_parity   = false,
#if defined (UART_PRESENT)
        .baud_rate    = NRF_UARTE_BAUDRATE_2400
#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);
}

on nrf52805 but I continue to have the communication error, what am I wrong?

the Handler function is:

void uart_event_handle(app_uart_evt_t * p_event)
{
   
    static uint8_t index = 0;
    uint32_t       err_code;

    switch (p_event->evt_type)
    {
        case APP_UART_DATA_READY:
            UNUSED_VARIABLE(app_uart_get(&tx_payload.data[index]));
            index++;

            if ((tx_payload.data[index - 1] == '\n') ||
                (tx_payload.data[index - 1] == '\r') ||
                (index >= 20))// valore massimo da poter invare su uart suggerimento preso dall'esempio del ble_uart
            {
                if (index > 1)
                {
                    NRF_LOG_DEBUG("Ready to send data over UARTE");
                    NRF_LOG_HEXDUMP_DEBUG(tx_payload.data, index);
                }

                index = 0;
            }
            break;

        case APP_UART_COMMUNICATION_ERROR:
            APP_ERROR_HANDLER(p_event->data.error_communication);
            break;

        case APP_UART_FIFO_ERROR:
            APP_ERROR_HANDLER(p_event->data.error_code);
            break;

        default:
            break;
    }
}

[Sigurd]

Ilary said:

I have at this point enabled flow control with the code

1) You are still seeing the problem with flow-control enabled?

2) What is the value of UART_TX_BUF_SIZE and UART_RX_BUF_SIZE?

3) What is the value of p_event->data.error_communication , when this happens?

[Ilary]

1. yes, I still have the error.

2. both tx_buf_size and rx_buf_size have a value of 256, such as the example of the ble_uart

3. value is always APP_UART_COMMUNICATION_ERROR

[Sigurd]

Ilary said:

3. value is always APP_UART_COMMUNICATION_ERROR

APP_UART_COMMUNICATION_ERROR is the event, but there is a value found in p_event->data.error_communication aswell, you should debug and check this value when you get the APP_UART_COMMUNICATION_ERROR event.

Also, when do you get APP_UART_COMMUNICATION_ERROR? How many bytes did you receive before the error?