问题：
1、串口引脚的切换的，一组引脚（A）切换到另一组引脚(B)上，开始发送数据时发现有部分数据仍然发送到了A组引脚上
2、串口发送大量数据（500字节以上），连续发送，通过串口工具检测发现没有完全发送出去，如何判断每次数据发送完毕

谢谢大家抽空看看源码

#include "uart.h"
#include "nrf_uart.h"
#include "app_uart.h"
#include "nrf_drv_uart.h"
#include "nrf_error.h"

u8 UART_RX_BUF[UART_REC_LEN]; //接收缓冲,最大UART_REC_LEN个字节
u16 UART_RX_LEN = 0; //接收数据长度

void UartEventHandler(app_uart_evt_t * p_event)
{
UBaseType_t uxSavedInterruptStatus;

uxSavedInterruptStatus = taskENTER_CRITICAL_FROM_ISR();
switch (p_event->evt_type)
{
    case APP_UART_DATA_READY:
            UNUSED_VARIABLE(app_uart_get(&UART_RX_BUF[UART_RX_LEN]));
            UART_RX_LEN++;
            if(UART_RX_LEN >=UART_REC_LEN )UART_RX_LEN = 0;
            break;
    default:
        break;
}
taskEXIT_CRITICAL_FROM_ISR(uxSavedInterruptStatus);

}

void UART0_Deinit(void)
{
app_uart_close();
memset((u8*)UART_RX_BUF,0,sizeof(UART_RX_BUF));
UART_RX_LEN=0;
}

void UART0_Init(uint8_t UART_PIN)
{
uint32_t err_code;
uint8_t uart_tx_pin_num = 0;
uint8_t uart_rx_pin_num = 0;

UART0_Deinit();
switch(UART_PIN)
{
    case 0:
        uart_tx_pin_num = 11;
        uart_rx_pin_num = 12;
        break;
    case 1:
        uart_tx_pin_num = 22;
        uart_rx_pin_num = 23;
        break;
    case 2:
        uart_tx_pin_num = 29;
        uart_rx_pin_num = 30;
        break;
}
const app_uart_comm_params_t comm_params =
{
    .rx_pin_no    = uart_rx_pin_num,    //设置接收引脚
    .tx_pin_no    = uart_tx_pin_num,    //设置发送引脚
    .rts_pin_no   = NRF_UART_PSEL_DISCONNECTED,
    .cts_pin_no   = NRF_UART_PSEL_DISCONNECTED,
    .flow_control = APP_UART_FLOW_CONTROL_DISABLED,
    .use_parity   = false,
    .baud_rate    = NRF_UART_BAUDRATE_115200
};

APP_UART_FIFO_INIT(&comm_params
                   , 1024
                   , 1024
                   , UartEventHandler
                   , APP_IRQ_PRIORITY_HIGHEST//APP_IRQ_PRIORITY_LOWEST
                   , err_code
                  );

APP_ERROR_CHECK(err_code);

}

void UART_SendData(uint8_t *data, uint16_t size)
{
taskENTER_CRITICAL();
for(uint16_t i = 0; i < size; i++)
{
UNUSED_VARIABLE(app_uart_put((uint8_t)data));//串口发送数据
}
taskEXIT_CRITICAL();
}