nRF52840 UART libraries

RE: nRF52840 UART libraries

masterLee — Tue, 30 Oct 2018 15:02:50 GMT

Thank you Martin!

RE: nRF52840 UART libraries

masterLee — Tue, 30 Oct 2018 14:31:45 GMT

Thanks a lot Martin!

RE: nRF52840 UART libraries

MartinBL — Tue, 30 Oct 2018 14:08:48 GMT

Yes, that is correct. And instead of :

nrf_uart_task_trigger(NRF_UART0, NRF_UART0->TASKS_STARTTX);

you should use:

nrf_uart_task_trigger(NRF_UART0, NRF_UART_TASK_STARTTX);

RE: nRF52840 UART libraries

masterLee — Tue, 30 Oct 2018 13:38:29 GMT

So,if I understand right I can put NRF_UART_EVENT_TXDRDY directly inside the function without pointer? Or create an nrf_uart_event_t instance and point to it with the dot operator?

Thank you for your help

RE: nRF52840 UART libraries

MartinBL — Tue, 30 Oct 2018 13:31:19 GMT

The parameters you use may point to the task and event address in the UART peripheral, but that is not what the function wants. Look at the function definition of nrf_uart_event_check() f.eks.:

__STATIC_INLINE bool nrf_uart_event_check(NRF_UART_Type * p_reg, nrf_uart_event_t event)
{
    return (bool)*(volatile uint32_t *)((uint8_t *)p_reg + (uint32_t)event);
}

nrf_uart_task_t and event_t are enums with offset values relative to the UART base address:

/**
 * @enum nrf_uart_task_t
 * @brief UART tasks.
 */
typedef enum
{
    /*lint -save -e30 -esym(628,__INTADDR__)*/
    NRF_UART_TASK_STARTRX = offsetof(NRF_UART_Type, TASKS_STARTRX), /**< Task for starting reception. */
    NRF_UART_TASK_STOPRX  = offsetof(NRF_UART_Type, TASKS_STOPRX),  /**< Task for stopping reception. */
    NRF_UART_TASK_STARTTX = offsetof(NRF_UART_Type, TASKS_STARTTX), /**< Task for starting transmission. */
    NRF_UART_TASK_STOPTX  = offsetof(NRF_UART_Type, TASKS_STOPTX),  /**< Task for stopping transmission. */
    NRF_UART_TASK_SUSPEND = offsetof(NRF_UART_Type, TASKS_SUSPEND), /**< Task for suspending UART. */
    /*lint -restore*/
} nrf_uart_task_t;

/**
 * @enum nrf_uart_event_t
 * @brief UART events.
 */
typedef enum
{
    /*lint -save -e30*/
    NRF_UART_EVENT_CTS    = offsetof(NRF_UART_Type, EVENTS_CTS),   /**< Event from CTS line activation. */
    NRF_UART_EVENT_NCTS   = offsetof(NRF_UART_Type, EVENTS_NCTS),  /**< Event from CTS line deactivation. */
    NRF_UART_EVENT_RXDRDY = offsetof(NRF_UART_Type, EVENTS_RXDRDY),/**< Event from data ready in RXD. */
    NRF_UART_EVENT_TXDRDY = offsetof(NRF_UART_Type, EVENTS_TXDRDY),/**< Event from data sent from TXD. */
    NRF_UART_EVENT_ERROR  = offsetof(NRF_UART_Type, EVENTS_ERROR), /**< Event from error detection. */
    NRF_UART_EVENT_RXTO   = offsetof(NRF_UART_Type, EVENTS_RXTO)   /**< Event from receiver timeout. */
    /*lint -restore*/
} nrf_uart_event_t;

RE: nRF52840 UART libraries

masterLee — Tue, 30 Oct 2018 13:09:37 GMT

One last question though,

in the nrf_uart_task_trigger() and nrf_uart_event_check() of my code, the parameters are nrf_uart_task_t and event_t. At least that is were UART0 is pointing in both cases. Should I put this without a pointer?

Thank you

RE: nRF52840 UART libraries

MartinBL — Tue, 30 Oct 2018 12:58:51 GMT

Happy to help!

RE: nRF52840 UART libraries

masterLee — Tue, 30 Oct 2018 12:52:33 GMT

Thank you for your help Martin.

RE: nRF52840 UART libraries

MartinBL — Tue, 30 Oct 2018 12:37:19 GMT

Hi,

In addition to what ipshiv said, you can read more about the UART HAL and driver here, and about the difference between app_uart and nrf_serial here.

As for your code; you are passing invalid parameters into nrf_uart_task_trigger() and nrf_uart_event_check(). You need to pass parameters of types nrf_uart_task_t and nrf_uarte_event_t respectively.

Anyway I suggest that you use the drivers anda libraries instead of the HAL directly. Then you can rely on the driver documentation and examples.

RE: nRF52840 UART libraries

masterLee — Tue, 30 Oct 2018 07:45:53 GMT

Hi, thank you for your reply.

Interesting tip. The library you refer is located in nRF5_SDK_15.2.0_9412b96\components\libraries\serial. Correct?

Do you know if there are hardware abstraction libraries like the one for uart, for other onboard peripherals like I2C, SPI, ADC etc?

Thanks

RE: nRF52840 UART libraries

ipshiv — Tue, 30 Oct 2018 05:23:55 GMT

Good day!

I've just started to work with new versions of SDK and NRF52, but NRF51 and older version used drivers to work with specified peripheral and app is a hardware abstraction, which means that functions doesn't depend of board you are using. Also you can use app libraries with softdevice, driver libraries may cause a problem.