Output/blinky_pca10056 Release/Obj/main.o: in function `uart_init'

Question

Hi, I try to combine example Blinky with Uart. but i have problem error as link below

Output/blinky_pca10056 Release/Obj/main.o: in function `uart_init':

undefined reference to `app_uart_init'

please check my code

my code


#include <stdbool.h>
#include <stdint.h>
#include <stdio.h>
#include "nrf_delay.h"
#include "boards.h"


#include "app_uart.h"
#include "app_error.h"
#include "nrf.h"
#include "bsp.h"


#if defined (UART_PRESENT)
#include "nrf_uart.h"
#endif
#if defined (UARTE_PRESENT)
#include "nrf_uarte.h"
#endif

 
#define LED1          NRF_GPIO_PIN_MAP(0,7)
#define LED2          NRF_GPIO_PIN_MAP(0,17)
#define LED3          NRF_GPIO_PIN_MAP(1,0)
#define LED4          NRF_GPIO_PIN_MAP(0,10)

#define BT1           NRF_GPIO_PIN_MAP(0,15)
#define BT2           NRF_GPIO_PIN_MAP(0,20)
#define BT3           NRF_GPIO_PIN_MAP(0,22)
#define BT4           NRF_GPIO_PIN_MAP(0,9)
/**
 * @brief Function for application main entry.
 */

// const uint32_t UICR_ADDR_0x20C    __attribute__((at(0x1000120C))) __attribute__((used)) = 0xFFFFFFFE;


//#define ENABLE_LOOPBACK_TEST  /**< if defined, then this example will be a loopback test, which means that TX should be connected to RX to get data loopback. */

#define MAX_TEST_DATA_BYTES     (15U)                /**< max number of test bytes to be used for tx and rx. */
#define UART_TX_BUF_SIZE 256                         /**< UART TX buffer size. */
#define UART_RX_BUF_SIZE 256                         /**< UART RX buffer size. */


void uart_error_handle(app_uart_evt_t * p_event)
{
    if (p_event->evt_type == APP_UART_COMMUNICATION_ERROR)
    {
        APP_ERROR_HANDLER(p_event->data.error_communication);
    }
    else if (p_event->evt_type == APP_UART_FIFO_ERROR)
    {
        APP_ERROR_HANDLER(p_event->data.error_code);
    }
}










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

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

            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;
    }
}



/**@brief  Function for initializing the UART module.
 */
/**@snippet [UART Initialization] */
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_115200
#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);
}
/**@snippet [UART Initialization] */

 




int main(void)
{
    /* Configure board. */
    //bsp_board_init(BSP_INIT_LEDS);
     uint32_t err_code;
     uart_init();


     nrf_gpio_cfg_output(LED1);
     nrf_gpio_cfg_output(LED2);
     nrf_gpio_cfg_output(LED3);
     nrf_gpio_cfg_output(LED4);

     nrf_gpio_cfg_input(BT1, NRF_GPIO_PIN_PULLUP);
     nrf_gpio_cfg_input(BT2, NRF_GPIO_PIN_PULLUP);
     nrf_gpio_cfg_input(BT3, NRF_GPIO_PIN_PULLUP);
     nrf_gpio_cfg_input(BT4, NRF_GPIO_PIN_PULLUP);
 

    while (true)
    {

//      nrf_delay_ms(100);
//      nrf_gpio_pin_toggle(LED1);
//      nrf_gpio_pin_toggle(LED2);
//      nrf_gpio_pin_toggle(LED3);
//      nrf_gpio_pin_toggle(LED4);
       uint32_t sb1 = nrf_gpio_pin_read(BT1);
       uint32_t sb2 = nrf_gpio_pin_read(BT2);
       uint32_t sb3 = nrf_gpio_pin_read(BT3);
       uint32_t sb4 = nrf_gpio_pin_read(BT4);

       nrf_gpio_pin_write(LED1, sb1);
       nrf_gpio_pin_write(LED2, sb2);
       nrf_gpio_pin_write(LED3, sb3);
       nrf_gpio_pin_write(LED4, sb4);
    }
}

/**
 *@}
 **/