一、简介

UARTE 是带有 EasyDMA 的通用异步接收器/发送器 UART。提供快速、全双工、异步的串口通信，内置流量控制（CTS，RTS）支持硬件，速率高达 1 Mbps。

以下是 UARTE 的主要功能：

• 全双工操作
• 自动硬件流控制
• 生成9位数据带奇偶校验
• EasyDMA
• 波特率高达 1 Mbps
• 在支持的事务之间返回 IDLE（使用HW流控制时）
• 一个停止位
• 最低有效位（LSB）优先

用于每个 UART 接口的 GPIO 可以从设备上的任何 GPIO 来选择并且独立地为可配置的。这使得能够在器件的引脚和有效地利用电路板空间和信号路有很大的灵活性。

二、硬件连接

三、修改文件

3.1 app_uart.h

app_uart.h 位于 SDK\components\libraries\uart，将原文件备份，将以下内容替换到原文件

#ifndef APP_UART_H__
#define APP_UART_H__

#include <stdint.h>
#include <stdbool.h>
#include "app_util_platform.h"
#include "nrf_drv_uart.h"
#include "app_fifo.h"


#ifdef __cplusplus
extern "C" { 
#endif

#define UART_PIN_DISCONNECTED 0xFFFFFFFF 


typedef enum
{ 
    APP_UART_FLOW_CONTROL_DISABLED, 
    APP_UART_FLOW_CONTROL_ENABLED,  
} app_uart_flow_control_t;


typedef struct
{ 
    uint32_t                rx_pin_no;    
    uint32_t                tx_pin_no;    
    uint32_t                rts_pin_no;   
    uint32_t                cts_pin_no;   
    app_uart_flow_control_t flow_control; 
    bool                    use_parity;   
    uint32_t                baud_rate;    
} app_uart_comm_params_t;


typedef struct
{ 
    uint8_t * rx_buf;      
    uint32_t  rx_buf_size; 
    uint8_t * tx_buf;      
    uint32_t  tx_buf_size; 
} app_uart_buffers_t;


typedef enum
{ 
    APP_UART_DATA_READY,          
    APP_UART_FIFO_ERROR,          
    APP_UART_COMMUNICATION_ERROR, 
    APP_UART_TX_EMPTY,            
    APP_UART_DATA,                
} app_uart_evt_type_t;


typedef struct
{ 
    app_uart_evt_type_t evt_type; 
    union
    { 
        uint32_t error_communication; 
        uint32_t error_code;          
        uint8_t  value;               
    } data;
} app_uart_evt_t;


typedef void (* app_uart_event_handler_t) (app_uart_evt_t * p_app_uart_event);

struct nrf_uart_obj{ 
	nrf_drv_uart_t		instance;
	bool rx_done;
	bool rx_ovf;
	app_uart_event_handler_t   event_handler;
	uint8_t tx_buffer[1];
	uint8_t rx_buffer[1];
	app_fifo_t rx_fifo;    
	app_fifo_t tx_fifo;
	app_uart_comm_params_t const* comm_params;
};
typedef struct nrf_uart_obj nrf_uart_obj_t;

#define APP_UART_DEF(_name, _instance, _buf_size, _event_handler) \ static uint8_t _name##_rx_buf[_buf_size]; \ static uint8_t _name##_tx_buf[_buf_size]; \ static app_uart_buffers_t _name##_buffers = { \ .rx_buf = _name##_rx_buf, \ .rx_buf_size = sizeof (_name##_rx_buf), \ .tx_buf = _name##_tx_buf, \ .tx_buf_size = sizeof (_name##_tx_buf), \ }; \ nrf_uart_obj_t _name = {\ .instance = NRF_DRV_UART_INSTANCE(_instance),\ .rx_done = false,\ .rx_ovf = false,\ .event_handler = _event_handler,\ }


#define APP_UART_FIFO_INIT(P_COMM_PARAMS, RX_BUF_SIZE, TX_BUF_SIZE, EVT_HANDLER, IRQ_PRIO, ERR_CODE) \ do \ { \ app_uart_buffers_t buffers; \ static uint8_t rx_buf[RX_BUF_SIZE]; \ static uint8_t tx_buf[TX_BUF_SIZE]; \ \ buffers.rx_buf = rx_buf; \ buffers.rx_buf_size = sizeof (rx_buf); \ buffers.tx_buf = tx_buf; \ buffers.tx_buf_size = sizeof (tx_buf); \ ERR_CODE = app_uart_init(P_COMM_PARAMS, &buffers, EVT_HANDLER, IRQ_PRIO); \ } while (0)


#define APP_UART_INIT(P_COMM_PARAMS, EVT_HANDLER, IRQ_PRIO, ERR_CODE) \ do \ { \ ERR_CODE = app_uart_init(P_COMM_PARAMS, NULL, EVT_HANDLER, IRQ_PRIO); \ } while (0)


uint32_t app_uart_init(nrf_uart_obj_t * uart_obj,
                             app_uart_buffers_t *     p_buffers,
                             app_irq_priority_t       irq_priority);


uint32_t app_uart_get(nrf_uart_obj_t * uart_obj, uint8_t * p_byte);


uint32_t app_uart_put(nrf_uart_obj_t * uart_obj, uint8_t byte);


uint32_t app_uart_flush(nrf_uart_obj_t * uart_obj);


uint32_t app_uart_close(nrf_uart_obj_t * uart_obj);


#ifdef __cplusplus
}
#endif

#endif //APP_UART_H__

3.2 app_uart_fifo.c

app_uart_fifo.c 位于 SDK\components\libraries\uart，将原文件备份，将以下内容替换到原文件

#include "sdk_common.h"
#if NRF_MODULE_ENABLED(APP_UART)
#include "app_uart.h"

#include "nrf_drv_uart.h"
#include "nrf_assert.h"

//static nrf_drv_uart_t app_uart_inst = NRF_DRV_UART_INSTANCE(APP_UART_DRIVER_INSTANCE);

static __INLINE uint32_t fifo_length(app_fifo_t * const fifo)
{ 
  uint32_t tmp = fifo->read_pos;
  return fifo->write_pos - tmp;
}

#define FIFO_LENGTH(F) fifo_length(&F) 


//static app_uart_event_handler_t m_event_handler; 
//static uint8_t tx_buffer[1];
//static uint8_t rx_buffer[1];
//static bool m_rx_ovf;

//static app_fifo_t m_rx_fifo; 
//static app_fifo_t m_tx_fifo; 

static void uart_event_handler(nrf_drv_uart_event_t * p_event, void* p_context)
{ 
    app_uart_evt_t app_uart_event;
    uint32_t err_code;

    nrf_uart_obj_t * uart_obj = (nrf_uart_obj_t *)p_context;

    switch (p_event->type)
    { 
        case NRF_DRV_UART_EVT_RX_DONE:
            // If 0, then this is a RXTO event with no new bytes.
            if(p_event->data.rxtx.bytes == 0)
            { 
               // A new start RX is needed to continue to receive data
               (void)nrf_drv_uart_rx(&uart_obj->instance, uart_obj->rx_buffer, 1);
               break;
            }

            // Write received byte to FIFO.
            err_code = app_fifo_put(&uart_obj->rx_fifo, p_event->data.rxtx.p_data[0]);
            if (err_code != NRF_SUCCESS)
            { 
                app_uart_event.evt_type          = APP_UART_FIFO_ERROR;
                app_uart_event.data.error_code   = err_code;
                uart_obj->event_handler(&app_uart_event);
            }
            // Notify that there are data available.
            else if (FIFO_LENGTH(uart_obj->rx_fifo) != 0)
            { 
                app_uart_event.evt_type = APP_UART_DATA_READY;
                uart_obj->event_handler(&app_uart_event);
            }

            // Start new RX if size in buffer.
            if (FIFO_LENGTH(uart_obj->rx_fifo) <= uart_obj->rx_fifo.buf_size_mask)
            { 
                (void)nrf_drv_uart_rx(&uart_obj->instance, uart_obj->rx_buffer, 1);
            }
            else
            { 
                // Overflow in RX FIFO.
                uart_obj->rx_ovf = true;
            }

            break;

        case NRF_DRV_UART_EVT_ERROR:
            app_uart_event.evt_type                 = APP_UART_COMMUNICATION_ERROR;
            app_uart_event.data.error_communication = p_event->data.error.error_mask;
            (void)nrf_drv_uart_rx(&uart_obj->instance, uart_obj->rx_buffer, 1);
            uart_obj->event_handler(&app_uart_event);
            break;

        case NRF_DRV_UART_EVT_TX_DONE:
            // Get next byte from FIFO.
            if (app_fifo_get(&uart_obj->tx_fifo, uart_obj->tx_buffer) == NRF_SUCCESS)
            { 
                (void)nrf_drv_uart_tx(&uart_obj->instance, uart_obj->tx_buffer, 1);
            }
            else
            { 
                // Last byte from FIFO transmitted, notify the application.
                app_uart_event.evt_type = APP_UART_TX_EMPTY;
                uart_obj->event_handler(&app_uart_event);
            }
            break;

        default:
            break;
    }
}


uint32_t app_uart_init(nrf_uart_obj_t * uart_obj,
                             app_uart_buffers_t *     p_buffers,
                             app_irq_priority_t       irq_priority)
{ 
    uint32_t err_code;

// m_event_handler = event_handler;

    if (p_buffers == NULL)
    { 
        return NRF_ERROR_INVALID_PARAM;
    }

    // Configure buffer RX buffer.
    err_code = app_fifo_init(&uart_obj->rx_fifo, p_buffers->rx_buf, p_buffers->rx_buf_size);
    VERIFY_SUCCESS(err_code);

    // Configure buffer TX buffer.
    err_code = app_fifo_init(&uart_obj->tx_fifo, p_buffers->tx_buf, p_buffers->tx_buf_size);
    VERIFY_SUCCESS(err_code);

    nrf_drv_uart_config_t config = NRF_DRV_UART_DEFAULT_CONFIG;
    config.baudrate = (nrf_uart_baudrate_t)uart_obj->comm_params->baud_rate;
    config.hwfc = (uart_obj->comm_params->flow_control == APP_UART_FLOW_CONTROL_DISABLED) ?
            NRF_UART_HWFC_DISABLED : NRF_UART_HWFC_ENABLED;
    config.interrupt_priority = irq_priority;
    config.parity = uart_obj->comm_params->use_parity ? NRF_UART_PARITY_INCLUDED : NRF_UART_PARITY_EXCLUDED;
    config.pselcts = uart_obj->comm_params->cts_pin_no;
    config.pselrts = uart_obj->comm_params->rts_pin_no;
    config.pselrxd = uart_obj->comm_params->rx_pin_no;
    config.pseltxd = uart_obj->comm_params->tx_pin_no;
    config.p_context = uart_obj;

    err_code = nrf_drv_uart_init(&uart_obj->instance, &config, uart_event_handler);
    VERIFY_SUCCESS(err_code);
    uart_obj->rx_ovf = false; 

    // Turn on receiver if RX pin is connected
    if (uart_obj->comm_params->rx_pin_no != UART_PIN_DISCONNECTED)
    { 
        return nrf_drv_uart_rx(&uart_obj->instance, uart_obj->rx_buffer,1);
    }
    else
    { 
        return NRF_SUCCESS;
    }
}


uint32_t app_uart_flush(nrf_uart_obj_t * uart_obj)
{ 
    uint32_t err_code;

    err_code = app_fifo_flush(&uart_obj->rx_fifo);
    VERIFY_SUCCESS(err_code);

    err_code = app_fifo_flush(&uart_obj->tx_fifo);
    VERIFY_SUCCESS(err_code);

    return NRF_SUCCESS;
}


uint32_t app_uart_get(nrf_uart_obj_t * uart_obj, uint8_t * p_byte)
{ 
    ASSERT(p_byte);
    bool rx_ovf = uart_obj->rx_ovf;

    ret_code_t err_code =  app_fifo_get(&uart_obj->rx_fifo, p_byte);

    // If FIFO was full new request to receive one byte was not scheduled. Must be done here.
    if (rx_ovf)
    { 
        uart_obj->rx_ovf = false;
        uint32_t uart_err_code = nrf_drv_uart_rx(&uart_obj->instance, uart_obj->rx_buffer, 1);

        // RX resume should never fail.
        APP_ERROR_CHECK(uart_err_code);
    }

    return err_code;
}


uint32_t app_uart_put(nrf_uart_obj_t * uart_obj, uint8_t byte)
{ 
    uint32_t err_code;
    err_code = app_fifo_put(&uart_obj->tx_fifo, byte);
    if (err_code == NRF_SUCCESS)
    { 
        // The new byte has been added to FIFO. It will be picked up from there
        // (in 'uart_event_handler') when all preceding bytes are transmitted.
        // But if UART is not transmitting anything at the moment, we must start
        // a new transmission here.
        if (!nrf_drv_uart_tx_in_progress(&uart_obj->instance))
        { 
            // This operation should be almost always successful, since we've
            // just added a byte to FIFO, but if some bigger delay occurred
            // (some heavy interrupt handler routine has been executed) since
            // that time, FIFO might be empty already.
            if (app_fifo_get(&uart_obj->tx_fifo, uart_obj->tx_buffer) == NRF_SUCCESS)
            { 
                err_code = nrf_drv_uart_tx(&uart_obj->instance, uart_obj->tx_buffer, 1);
            }
        }
    }
    return err_code;
}


uint32_t app_uart_close(nrf_uart_obj_t * uart_obj)
{ 
    nrf_drv_uart_uninit(&uart_obj->instance);
    return NRF_SUCCESS;
}

#endif //NRF_MODULE_ENABLED(APP_UART)

3.3 retarget.c

retarget.c 位于 SDK\components\libraries\uart，将原文件备份，将以下内容替换到原文件

#include "sdk_common.h"

#if NRF_MODULE_ENABLED(RETARGET)
#if !defined(NRF_LOG_USES_RTT) || NRF_LOG_USES_RTT != 1
#if !defined(HAS_SIMPLE_UART_RETARGET)


#include <stdio.h>
#include <stdint.h>
#include "app_uart.h"
#include "nrf_error.h"


#if defined(__CC_ARM)

// This part is taken from MDK-ARM template file and is required here to prevent
// linker from selecting libraries functions that use semihosting and failing
// because of multiple definitions of fgetc() and fputc().
// Refer to: http://www.keil.com/support/man/docs/gsac/gsac_retargetcortex.htm
// -- BEGIN --
struct __FILE {  int handle;  };
FILE __stdout;
FILE __stdin;
// --- END ---

extern uint32_t _app_uart_get(uint8_t * p_byte);
extern uint32_t _app_uart_put(uint8_t byte);

int fgetc(FILE * p_file)
{ 
    uint8_t input;
    while (_app_uart_get(&input) == NRF_ERROR_NOT_FOUND)
    { 
        // No implementation needed.
    }
    return input;
}

int fputc(int ch, FILE * p_file)
{ 
    UNUSED_PARAMETER(p_file);

    UNUSED_VARIABLE(_app_uart_put((uint8_t)ch));
    return ch;
}

#elif defined(__GNUC__) && defined(__SES_ARM)

int __getchar(FILE * p_file)
{ 
    uint8_t input;
    while (app_uart_get(&input) == NRF_ERROR_NOT_FOUND)
    { 
        // No implementation needed.
    }
    return input;
}

#if defined(__SES_VERSION) && (__SES_VERSION >= 34000)
int __putchar(int ch, __printf_tag_ptr tag_ptr)
{ 
    UNUSED_PARAMETER(tag_ptr);

    UNUSED_VARIABLE(app_uart_put((uint8_t)ch));
    return ch;
}
#else
int __putchar(int ch, FILE * p_file)
{ 
    UNUSED_PARAMETER(p_file);

    UNUSED_VARIABLE(app_uart_put((uint8_t)ch));
    return ch;
}
#endif

#elif defined(__GNUC__) && !defined(__SES_ARM)

int _write(int file, const char * p_char, int len)
{ 
    int i;

    UNUSED_PARAMETER(file);

    for (i = 0; i < len; i++)
    { 
        UNUSED_VARIABLE(app_uart_put(*p_char++));
    }

    return len;
}

int _read(int file, char * p_char, int len)
{ 
    UNUSED_PARAMETER(file);
    while (app_uart_get((uint8_t *)p_char) == NRF_ERROR_NOT_FOUND)
    { 
        // No implementation needed.
    }

    return 1;
}
#elif defined(__ICCARM__)

size_t __write(int handle, const unsigned char * buffer, size_t size)
{ 
    int i;
    UNUSED_PARAMETER(handle);
    for (i = 0; i < size; i++)
    { 
        UNUSED_VARIABLE(app_uart_put(*buffer++));
    }
    return size;
}

size_t __read(int handle, unsigned char * buffer, size_t size)
{ 
    UNUSED_PARAMETER(handle);
    UNUSED_PARAMETER(size);
    while (app_uart_get((uint8_t *)buffer) == NRF_ERROR_NOT_FOUND)
    { 
        // No implementation needed.
    }

    return 1;
}

long __lseek(int handle, long offset, int whence)
{ 
    return -1;
}
int __close(int handle)
{ 
    return 0;
}
int remove(const char * filename)
{ 
    return 0;
}

#endif

#endif // !defined(HAS_SIMPLE_UART_RETARGET)
#endif // NRF_LOG_USES_RTT != 1
#endif //NRF_MODULE_ENABLED(RETARGET)

四、移植文件

链接：https://pan.baidu.com/s/1eyT7_gK1MBkvk9PNVT_u3g 提取码：h664
将 board_uart.c 和 board_uart.h 两个文件加入工程的Application文件夹下

4.1 board_uart.c

#include "nrf_uart.h"
#include "app_uart.h"
#include "nrf_log.h"

#include "board_uart.h"

static void uart0_handleEvent(app_uart_evt_t *pEvent);
static void uart1_handleEvent(app_uart_evt_t *pEvent);




APP_UART_DEF(uart0, 0, UART_RX_BUF_SIZE, uart0_handleEvent);
APP_UART_DEF(uart1, 1, UART_RX_BUF_SIZE, uart1_handleEvent);
static uint8_t s_uart0ReadDataBuffer[UART_RX_BUF_SIZE] = { 0};
static uint8_t s_index = 0;
static bool s_begin = false;
static uint8_t s_uart1ReadDataBuffer[UART_RX_BUF_SIZE] = { 0};
static uint8_t s_index2 = 0;
static bool s_begin2 = false;



void UART_Init(void)
{ 
    uint32_t errCode;
    
    
    app_uart_comm_params_t const commParams_0 =
    { 
        .rx_pin_no    = BOARD_UART0_RX_IO,
        .tx_pin_no    = BOARD_UART0_TX_IO,
        .rts_pin_no   = NRF_UART_PSEL_DISCONNECTED,
        .cts_pin_no   = NRF_UART_PSEL_DISCONNECTED,                    
        .flow_control = APP_UART_FLOW_CONTROL_DISABLED,             // 关掉流控
        .use_parity   = false,
#if defined (UART_PRESENT)
        .baud_rate    = NRF_UART_BAUDRATE_115200                    // 波特率
#else
        .baud_rate    = NRF_UARTE_BAUDRATE_115200
#endif
    };
    uart0.comm_params = &commParams_0;
    errCode = app_uart_init(&uart0, &uart0_buffers, APP_IRQ_PRIORITY_LOWEST);
    APP_ERROR_CHECK(errCode);
    
    
    app_uart_comm_params_t const commParams_1 =
    { 
        .rx_pin_no    = BOARD_UART1_RX_IO,
        .tx_pin_no    = BOARD_UART1_TX_IO,
        .rts_pin_no   = NRF_UART_PSEL_DISCONNECTED,
        .cts_pin_no   = NRF_UART_PSEL_DISCONNECTED,                    
        .flow_control = APP_UART_FLOW_CONTROL_DISABLED,             // 关掉流控
        .use_parity   = false,
#if defined (UART_PRESENT)
        .baud_rate    = NRF_UART_BAUDRATE_115200                    // 波特率
#else
        .baud_rate    = NRF_UART_BAUDRATE_115200
#endif
    };
    uart1.comm_params = &commParams_1;
    errCode = app_uart_init(&uart1, &uart1_buffers, APP_IRQ_PRIORITY_LOWEST);
    APP_ERROR_CHECK(errCode);
}


void UART_WriteData(uint8_t uartNum, uint8_t *pData, uint8_t dataLen)
{ 
    uint8_t i;
    if(uartNum == 0)
    { 
        for(i = 0; i < dataLen; i++)
        { 
            app_uart_put(&uart0, pData[i]);
        }
    }
    else if(uartNum == 1)
    { 
        for(i = 0; i < dataLen; i++)
        { 
            app_uart_put(&uart0, pData[i]);
        }
    }
}

uint32_t _app_uart_get(uint8_t * p_byte)
{ 
    return app_uart_get(&uart1, p_byte);
}
uint32_t _app_uart_put(uint8_t byte)
{ 
    return app_uart_put(&uart1, byte);
}




static void uart0_handleEvent(app_uart_evt_t *pEvent)
{ 
    uint8_t dataChar = 0;

    switch(pEvent->evt_type)
    { 
        // 已接收到UART数据
        case APP_UART_DATA_READY:
        { 
            UNUSED_VARIABLE(app_uart_get(&uart0, &dataChar));
            
            // 不是回车符或换行符则开始 
            if(dataChar != '\n' && dataChar != '\r')
            { 
                s_begin = true;
            }
            if(s_begin)
            { 
                s_uart0ReadDataBuffer[s_index] = dataChar;
                s_index++;
            }

            // 遇到回车符或换行符结束 
            if((s_uart0ReadDataBuffer[s_index - 1] == '\n') ||
               (s_uart0ReadDataBuffer[s_index - 1] == '\r') ||
               (s_index >= MAX_RECV_BUF_SIZE))
            { 
				NRF_LOG_HEXDUMP_INFO(s_uart0ReadDataBuffer, s_index);   

                memset(s_uart0ReadDataBuffer, 0, s_index); 
                s_index = 0;
                s_begin = false;                
            }
        } break;

        // 接收过程中发生通信错误
        case APP_UART_COMMUNICATION_ERROR:
// APP_ERROR_HANDLER(pEvent->data.error_communication);
            break;

        // app_uart模块使用的FIFO模块中出现错误
        case APP_UART_FIFO_ERROR:
// APP_ERROR_HANDLER(pEvent->data.error_code);
            break;

        default:
            break;
    }
}


static void uart1_handleEvent(app_uart_evt_t *pEvent)
{ 
    uint8_t dataChar = 0;

    switch(pEvent->evt_type)
    { 
        // 已接收到UART数据
        case APP_UART_DATA_READY:
        { 
            UNUSED_VARIABLE(app_uart_get(&uart1, &dataChar));

            // 不是回车符或换行符则开始 
            if(dataChar != '\n' && dataChar != '\r')
            { 
                s_begin2 = true;
            }
            if(s_begin2)
            { 
                s_uart1ReadDataBuffer[s_index2] = dataChar;
                s_index2++;
            }

            // 遇到回车符或换行符结束 
            if((s_uart1ReadDataBuffer[s_index2 - 1] == '\n') ||
               (s_uart1ReadDataBuffer[s_index2 - 1] == '\r') ||
               (s_index2 >= MAX_RECV_BUF_SIZE))
            { 
				NRF_LOG_HEXDUMP_INFO(s_uart1ReadDataBuffer, s_index2);   

                memset(s_uart1ReadDataBuffer, 0, s_index2); 
                s_index2 = 0;
                s_begin2 = false;                
            }
        } break;

        // 接收过程中发生通信错误
        case APP_UART_COMMUNICATION_ERROR:
// APP_ERROR_HANDLER(pEvent->data.error_communication);
            break;

        // app_uart模块使用的FIFO模块中出现错误
        case APP_UART_FIFO_ERROR:
// APP_ERROR_HANDLER(pEvent->data.error_code);
            break;

        default:
            break;
    }
}

4.2 board_uart.h

#ifndef _BOARD_UART_H_
#define _BOARD_UART_H_


#include "nrf_gpio.h"


#define UART_TX_BUF_SIZE 256 // UART TX buffer size
#define UART_RX_BUF_SIZE 256 // UART RX buffer size

// UART0
#define BOARD_UART0_TX_IO 6 // 发送引脚 
#define BOARD_UART0_RX_IO 8 // 接收引脚
// UART1
#define BOARD_UART1_TX_IO 5 // 发送引脚 
#define BOARD_UART1_RX_IO 7 // 接收引脚

#define UART0 0
#define UART1 1




void UART_Init(void);
void UART_WriteData(uint8_t uartNum, uint8_t *pData, uint8_t dataLen);

#endif 

五、API调用

需包含头文件 board_uart.h

UART_Init

UART_WriteData

六、SDK配置

点击 sdk_config.h 文件

选择 Configuration Wizard

nRF_Drivers 中勾选UART、UARTE、FIFO、STRERROR和RETARGET相关选项

有的工程 nRF_Libraries 没有 APP_FIFO_ENABLED、APP_UART_ENABLED、RETARGET_ENABLED，则在 sdk_config.h 6044行后加上

//==========================================================
// <q> APP_FIFO_ENABLED - app_fifo - Software FIFO implementation
#ifndef APP_FIFO_ENABLED
#define APP_FIFO_ENABLED 1
#endif

// <e> APP_UART_ENABLED - app_uart - UART driver
//==========================================================
#ifndef APP_UART_ENABLED
#define APP_UART_ENABLED 1
#endif
// <o> APP_UART_DRIVER_INSTANCE - UART instance used
 
// <0=> 0 

#ifndef APP_UART_DRIVER_INSTANCE
#define APP_UART_DRIVER_INSTANCE 0
#endif

// </e>

// <q> RETARGET_ENABLED - retarget - Retargeting stdio functions
#ifndef RETARGET_ENABLED
#define RETARGET_ENABLED 1
#endif

在 nRF_Drivers UART_ENABLED 上加上 UART1 使能

// <e> UART1_ENABLED - Enable UART1 instance
//==========================================================
#ifndef UART1_ENABLED
#define UART1_ENABLED 1
#endif
// <q> UART0_CONFIG_USE_EASY_DMA - Default setting for using EasyDMA
 

#ifndef UART1_CONFIG_USE_EASY_DMA
#define UART1_CONFIG_USE_EASY_DMA 1
#endif

// </e>

七、添加组件库

在 nRF_Drivers 文件夹和 nRF_Libraries 文件夹确认以下组件库是否存在，不存在则添加。

在主从一体的工程中后三个文件没有，需要添加：

1. 添加 app_uart_fifo.c 和 retarget.c
   
   
   
2. 添加 app_fifo.c
   
   
3. 添加上述编译文件路径
   
   

八、使用例子

1）添加头文件

#include "board_uart.h"

2）添加初始化代码
加入 UART_Init()

int main(void)
{ 
	bool erase_bonds;

    
	// Initialize.
    log_init();																	// 日志驱动初始化 
    timers_init();																// 定时器驱动初始化（在此加入自定义定时器）
	UART_Init();																// SI522驱动初始化（含SPI） 
	
	
    power_management_init();
    ble_stack_init();															// 协议栈初始化
    gap_params_init();
    gatt_init();
    advertising_init();															// 广播初始化
    services_init();															// 服务初始化
    conn_params_init();															// 连接参数初始化
    peer_manager_init();
	
	
	// Start execution.
    NRF_LOG_INFO("Template example started."); 
    advertising_start(erase_bonds);												// 开启广播 
	application_timers_start();													// 定时器应用开启（在此开启自定义定时器） 
	
    // Enter main loop.
    for(;;)
    { 
        idle_state_handle();
    }
}

3）写入串口数据

uint8_t temp[1] = { 0x01};
UART_WriteData(UART0, (uint8 *)&temp, 1);

UART_WriteData(UART1, (uint8 *)&temp, 1);

4）接收串口数据

• 由 Leung 写于 2020 年 12 月 17 日

• 参考：nrf52840的uart0与uart1双串口使用