因為需要使用串列埠傳送資料，而又決定自己寫韌體，所以就需要完成一項功能：

• ESP接收串列埠傳來的資料，並判斷
• 將接收的串列埠資料轉發出去

 ESP8266給串列埠傳送資料很容易

uart_sendString("串列埠傳送資料");

usrt0_sendStr("\r\n Hello World\r\n");

os_printf("傳送資料成功！！\r\n");

 這些語句都可以使用串列埠傳送資料，但是串列埠接收資料就不容易了。
 有時候，需要ESP8266接收資料並作出判斷。於是就搞出來這個程式了。

————————————————————

user_main.c

#include "ets_sys.h"
#include "osapi.h"
#include "user_interface.h"
#include "driver/uart.h"
#include "driver/pwm.h"
void delay_ms(uint16 x)
{
    for(;x>0;x--)
    {
    os_delay_us(1000);
    }
}

void user_init(void)
{
    uart_init(BIT_RATE_115200,BIT_RATE_115200);
    uart_sendString("串列埠傳送程式");
    //接收程式在uart.c uart0_rx_intr_handler(void *para)函式裡面
 

}

uart.c

#include "ets_sys.h"
#include "osapi.h"
#include "driver/uart.h"

#define UART0   0
#define UART1   1

// UartDev is defined and initialized in rom code.
extern UartDevice UartDev;

LOCAL void uart0_rx_intr_handler(void *para);//串列埠接收資料中斷函式

LOCAL void ICACHE_FLASH_ATTR
uart_config(uint8 uart_no)
{
    if
 
 (uart_no == UART1) {
        PIN_FUNC_SELECT(PERIPHS_IO_MUX_GPIO2_U, FUNC_U1TXD_BK);
    } else {
        /* rcv_buff size if 0x100 */
        ETS_UART_INTR_ATTACH(uart0_rx_intr_handler,  &(UartDev.rcv_buff));
        PIN_PULLUP_DIS(PERIPHS_IO_MUX_U0TXD_U);
        PIN_FUNC_SELECT(PERIPHS_IO_MUX_U0TXD_U, FUNC_U0TXD);
    }

    uart_div_modify(uart_no, UART_CLK_FREQ / (UartDev.baut_rate));

    WRITE_PERI_REG(UART_CONF0(uart_no),    UartDev.exist_parity
                   | UartDev.parity
                   | (UartDev.stop_bits << UART_STOP_BIT_NUM_S)
                   | (UartDev.data_bits << UART_BIT_NUM_S));


    //clear rx and tx fifo,not ready
    SET_PERI_REG_MASK(UART_CONF0(uart_no), UART_RXFIFO_RST | UART_TXFIFO_RST);
    CLEAR_PERI_REG_MASK(UART_CONF0(uart_no), UART_RXFIFO_RST | UART_TXFIFO_RST);

    //set rx fifo trigger
    WRITE_PERI_REG(UART_CONF1(uart_no), (UartDev.rcv_buff.TrigLvl & UART_RXFIFO_FULL_THRHD) << UART_RXFIFO_FULL_THRHD_S);

    //clear all interrupt
    WRITE_PERI_REG(UART_INT_CLR(uart_no), 0xffff);
    //enable rx_interrupt
    SET_PERI_REG_MASK(UART_INT_ENA(uart_no), UART_RXFIFO_FULL_INT_ENA);
}
/*************/
/*傳送一個字元*/
/*************/
LOCAL STATUS ICACHE_FLASH_ATTR
uart1_tx_one_char(uint8 TxChar)
{
    while (true)
    {
        uint32 fifo_cnt = READ_PERI_REG(UART_STATUS(UART1)) & (UART_TXFIFO_CNT<<UART_TXFIFO_CNT_S);
        if ((fifo_cnt >> UART_TXFIFO_CNT_S & UART_TXFIFO_CNT) < 126) {
            break;
        }
    }

    WRITE_PERI_REG(UART_FIFO(UART1) , TxChar);
    return OK;
}

LOCAL void ICACHE_FLASH_ATTR
uart1_write_char(char c)
{
    if (c == '\n') {
        uart1_tx_one_char('\r');
        uart1_tx_one_char('\n');
    } else if (c == '\r') {
    } else {
        uart1_tx_one_char(c);
    }
}
/*************************/
/**串列埠接收資料中斷處理函式**/
/************************/
LOCAL void
uart0_rx_intr_handler(void *para)
{
    /* uart0 and uart1 intr combine togther, when interrupt occur, see reg 0x3ff20020, bit2, bit0 represents
     * uart1 and uart0 respectively
     */
    RcvMsgBuff *pRxBuff = (RcvMsgBuff *)para;
    uint8 RcvChar;
    if (UART_RXFIFO_FULL_INT_ST != (READ_PERI_REG(UART_INT_ST(UART0)) & UART_RXFIFO_FULL_INT_ST)) {
        return;
    }
    WRITE_PERI_REG(UART_INT_CLR(UART0), UART_RXFIFO_FULL_INT_CLR);
    while (READ_PERI_REG(UART_STATUS(UART0)) & (UART_RXFIFO_CNT << UART_RXFIFO_CNT_S)) {
        RcvChar = READ_PERI_REG(UART_FIFO(UART0)) & 0xFF;
        uart_tx_one_char(RcvChar);
     //   uart0_tx_buffer(RcvChar,1);
        if (pRxBuff->pWritePos == (pRxBuff->pRcvMsgBuff + RX_BUFF_SIZE)) {
            // overflow ...we may need more error handle here.
            pRxBuff->pWritePos = pRxBuff->pRcvMsgBuff ;
        }
    }
}

void ICACHE_FLASH_ATTR
uart0_tx_buffer(uint8 *buf, uint16 len)
{
    uint16 i;

    for (i = 0; i < len; i++) {
        uart_tx_one_char(buf[i]);
    }
}
/*********************************/
/****串列埠初始化函式****/
/*********************************/
void ICACHE_FLASH_ATTR
uart_init(UartBautRate uart0_br, UartBautRate uart1_br)
{
    // rom use 74880 baut_rate, here reinitialize
    UartDev.baut_rate = uart0_br;
    uart_config(UART0);
    UartDev.baut_rate = uart1_br;
    uart_config(UART1);
    ETS_UART_INTR_ENABLE();

    // install uart1 putc callback
    os_install_putc1((void *)uart1_write_char);
}
void ICACHE_FLASH_ATTR
uart_sendString(uint8 *st)
{
    uint8 x;
    for(x=0;x<os_strlen(st);x++)
    {
        uart_tx_one_char(st[x]);
    }
}