How to send data using gpio (rx, tx pin)?

RE: How to send data using gpio (rx, tx pin)?

Jørgen Holmefjord — Wed, 11 Nov 2020 19:26:50 GMT

[quote user="lyrics"]Will TX_EMPTY be called when all the values of 0x11 are sent?[/quote]

The event will be generated whenever the FIFO is empty. When this is depends on how fast the application puts bytes into the FIFO, and how fast the UART peripheral is able to transmit the bytes.

[quote user="lyrics"]And since app_uart_get is defined in TX_EMPTY, err_code is not SUCCESS, where should I define it?[/quote]

You should call app_uart_get() in the APP_UART_DATA_READY event case, if you want to read the data as soon as it is received by the UART peripheral.

RE: How to send data using gpio (rx, tx pin)?

lyrics — Wed, 11 Nov 2020 08:08:12 GMT

Hi,

I got the event "APP_UART_TX_EMPTY" and looked at the flow with breakpoint,,

Will TX_EMPTY be called when all the values of 0x11 are sent?
And since app_uart_get is defined in TX_EMPTY, err_code is not SUCCESS, where should I define it?

RE: How to send data using gpio (rx, tx pin)?

jawadk — Wed, 11 Nov 2020 07:21:29 GMT

Hi Lyics,

you will got the "APP_UART_DATA_READY" event when you receive data over UART and not when you finish sending data, instead you will got the event "APP_UART_TX_EMPTY", this event indicating that UART has completed transmission of all available data in the TX FIFO, so use it as Nordix example uses the "APP_UART_DATA_READY" event .

Plus pay attention to what is the returned value you got from the function "app_uart_put" to see if you have any problem regarding the uard driver.

RE: How to send data using gpio (rx, tx pin)?

lyrics — Wed, 11 Nov 2020 00:45:47 GMT

Hi, jawadk

Thank you for your reply..

I sent the data through 'app_uart_put'.

If the data was sent well, shouldn't 'APP_UART_DATA_READY' be called on the code?..

Why isn't the event happening?

int main(void)
{
    bool erase_bonds;

    // Initialize.
    uart_init();

    send_data();

    // Enter main loop.
    while(true)
    {
          //receive_data();
    }
}

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,
        .baud_rate    = NRF_UART_BAUDRATE_9600
    };
//    nrf_gpio_cfg_input(RX_PIN_NUMBER, NRF_GPIO_PIN_NOPULL);
//    nrf_gpio_cfg_output(TX_PIN_NUMBER);

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

void send_data()
{
    uint32_t    err_code;
    uint8_t     send_data[UART_TX_BUF_SIZE];
    uint32_t    length = 4;

    send_data[0] = 0x11;
    send_data[1] = 0x01;
    send_data[2] = 0x01;
    send_data[3] = 0xed;

    for(uint32_t i = 0; i < length; i++)
    {
        {
            err_code = app_uart_put(send_data[i]);
            if ((err_code != NRF_SUCCESS) && (err_code != NRF_ERROR_BUSY))
            {
                NRF_LOG_ERROR("Failed Error 0x%x. ", err_code);
                APP_ERROR_CHECK(err_code);
            }
        } while (err_code == NRF_ERROR_BUSY);
    }
}

void uart_evt_callback(app_uart_evt_t * uart_evt) 
{
    uint8_t   byte;
    uint32_t  err_code;
    switch (uart_evt->evt_type)
    {
        case APP_UART_DATA_READY:
            printf("b\r\n"); 
            err_code = app_uart_get(&byte);
            if(err_code == NRF_SUCCESS)
            {
                printf("success..\r\n");
            }
        break;
        
        ...
        
    }
}

RE: How to send data using gpio (rx, tx pin)?

jawadk — Tue, 10 Nov 2020 09:42:23 GMT

Hi,

[quote userid="93536" url="~/f/nordic-q-a/68174/how-to-send-data-using-gpio-rx-tx-pin"]1. Is it correct to use 'app_uart_put' to send data?..[/quote]

Yes this is the function to send data over uart, this function sends one byte at a time so you need to make a for loop for sending all the bytes you mentioned above.

[quote userid="93536" url="~/f/nordic-q-a/68174/how-to-send-data-using-gpio-rx-tx-pin"]

2. Even if i do not receive the response data,, how can I check that those 0x11 ... data send well? (using nRF connect?)

[/quote]

You can use a UART to USB converter, plug it to your PC an use a terminal to open the right Comport to see the sent bytes from the board over UART.

[quote userid="93536" url="~/f/nordic-q-a/68174/how-to-send-data-using-gpio-rx-tx-pin"]

3. Am I have to initialize custom device's gpio, too?

[/quote]

You don't need to use custom gpios if you use the code and pins for pca10040

Hope this was helpful.

Best Regards