Using custom RX/TX UART pins on nrf51822

RE: Using custom RX/TX UART pins on nrf51822

Ricardo Rodrigues — Thu, 27 Aug 2020 13:35:22 GMT

Hi Jorgen,

My problem was actually of the PEBCAK category. The lines were named from the perspective of the other chip, so in reversing the TX and RX pins on my comm_params, all started working.

Many thanks for your support.

I accepted your last reply as the answer because I find that the code you posted my be useful for someone else wanting to debug their UART configuration.

Best regards,

Ricardo

RE: Using custom RX/TX UART pins on nrf51822

Jørgen Holmefjord — Thu, 27 Aug 2020 13:09:37 GMT

I tested your code in the UART example in SDK 12.3.0:

devzone.nordicsemi.com/.../main.c

I tested this on a nRF51 DK by connecting P0.17 to P0.09 and P0.18 to P0.11. It seems to work fine. Can you test this on your board?

RE: Using custom RX/TX UART pins on nrf51822

Ricardo Rodrigues — Thu, 27 Aug 2020 11:01:31 GMT

As a note, I am also not using logs through UART.

On sdk_config, i have:

#define NRF_LOG_BACKEND_SERIAL_USES_UART 0

#define NRF_LOG_BACKEND_SERIAL_USES_RTT 1

#define NRF_LOG_ENABLED 1

RE: Using custom RX/TX UART pins on nrf51822

Ricardo Rodrigues — Thu, 27 Aug 2020 10:45:36 GMT

void uart_init(on_uart_message_handler_t incoming_message_callback)
{
    uint32_t err_code;

    on_uart_incoming_message_handler = incoming_message_callback;

    const app_uart_comm_params_t comm_params = {
        //RX_PIN_NUMBER, TX_PIN_NUMBER,
        18,17,
        RTS_PIN_NUMBER, CTS_PIN_NUMBER,
        APP_UART_FLOW_CONTROL_DISABLED,
        false,
        MACRO_CONCAT_2(UART_BAUDRATE_BAUDRATE_Baud9600)
    };

    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: Using custom RX/TX UART pins on nrf51822

Jørgen Holmefjord — Thu, 27 Aug 2020 10:29:32 GMT

Hi,

Simply changing the pins and make sure no other peripheral is controlling the pins should be enough.

Can you share the code you used for configuring and initializing the UART peripheral/library?

Best regards,
Jørgen