nrf51822 button Bluetooth notification routine is added to serial port to print log

Connect the board and the PC with a miniUSB cable, install the cp2102 win7 64-bit driver, and
modify the code 1 of "Part 3: BLE Bluetooth Experiment\BLE Experiment 3: Button Bluetooth Notification\" Code
1, add a file

The file is located at:

Part 3: BLE Bluetooth Experiment\BLE Experiment 3: Button Bluetooth Notification\Source\simple_uart\simple_uart.c

Then add the following code to main.c:

#include "simple_uart.h"

/**@brief  Function for initializing the UART module.
 */
static void uart_init(void)
{
    /**@snippet [UART Initialization] */
    simple_uart_config(RTS_PIN_NUMBER, TX_PIN_NUMBER, CTS_PIN_NUMBER, RX_PIN_NUMBER, HWFC);

    NRF_UART0->INTENSET = UART_INTENSET_RXDRDY_Enabled << UART_INTENSET_RXDRDY_Pos;

    NVIC_SetPriority(UART0_IRQn, APP_IRQ_PRIORITY_LOW);
    NVIC_EnableIRQ(UART0_IRQn);
    /**@snippet [UART Initialization] */
}


/**@brief   Function for handling UART interrupts.
 *
 * @details This function will receive a single character from the UART and append it to a string.
 *          The string will be be sent over BLE when the last character received was a 'new line'
 *          i.e '\n' (hex 0x0D) or if the string has reached a length of @ref NUS_MAX_DATA_LENGTH.
 */
void UART0_IRQHandler(void)
{
    static uint8_t data_array[23];
    static uint8_t index = 0;
    uint32_t err_code;

    /**@snippet [Handling the data received over UART] */

    data_array[index] = simple_uart_get();
    index++;

    if ((data_array[index - 1] == '\n') || (index >= (23 - 1)))
    {
        #if 0
        err_code = ble_nus_send_string(&m_nus, data_array, index + 1);
        if (err_code != NRF_ERROR_INVALID_STATE)
        {
            APP_ERROR_CHECK(err_code);
        }
        #endif

        index = 0;
    }

    /**@snippet [Handling the data received over UART] */
}

The main function is as follows:

int main(void)
{
    // Initialize
    leds_init();
    timers_init();
    gpiote_init();
    buttons_init();
    uart_init();//外设初始化

    ble_stack_init();
    scheduler_init();    
    gap_params_init();
    services_init();
    advertising_init();
    conn_params_init();
    sec_params_init();

    simple_uart_putstring("ble_app_led");  
  // Start execution
    timers_start();

    advertising_start();

    // Enter main loop
    for (;;)
    {
        app_sched_execute();
        power_manage();
    }
}

Now it is only able to print strings, if it prints numbers, or how to use printf, further research is needed

In the experiment, a miniUSB cable is used on the j2 of the board to connect to the USB port of
the PC. In the win7 64-bit system of the PC, install the driver of cp2102, and then
set the correct serial port number and baud rate through UartAssist.exe 38400, you can see the correct data.