參考部落格：ESP8266(NODEMCU)Arduino環境下實現多個軟串列埠通訊

接線方式：

D5——D8
D6——D7

實驗原理與步驟

通過向硬串列埠傳送Show time 字串啟用微控制器去更新網路時間，然後通過軟串列埠一發出，然後硬串列埠會打出串列埠二接收到的資料。模擬了兩個微控制器實現串列埠通訊的過程。

程式碼

#include <NTPClient.h>
#include <ESP8266WiFi.h>
#include <WiFiUdp.h>
#include <SoftwareSerial.h>

SoftwareSerial uart1(14,12);//RX=d5,TX=d6
SoftwareSerial uart2(13,15);//RX=d7,TX=d8

//ESP8266 NODEMCU
const char *ssid     = "your wifi name ";
const char *password = "your wifi password";
WiFiUDP ntpUDP;
NTPClient timeClient(ntpUDP, "ntp1.aliyun.com",60*60*8, 30*60*1000);
void setup()
{
   Serial.begin(9600);
   uart1.begin(9600);
   uart2.begin(9600);
   uart1.listen();
   uart2.listen();
   pinMode(LED_BUILTIN, OUTPUT);     // Initialize the LED_BUILTIN pin as an output
   WiFi.begin(ssid, password);
   while ( WiFi.status() != WL_CONNECTED ) {
     delay ( 500 );
     Serial.print ( "." );
     digitalWrite(LED_BUILTIN, HIGH);
  }
  timeClient.begin();
}
String time1="";
bool dian=false;
int h,m,s,d;
String uart1string="";
String uart2string="";
void loop()
{
  
  if(Serial.available()>0){
    if(Serial.peek()!='\n'){
      uart1string+=(char)Serial.read();
    }
    else{
      Serial.read();
      if(uart1string=="Show time"){
        timeClient.update();
        time1=timeClient.getFormattedTime();
        uart1.println(time1);
      }
      uart1string="";
    }
  }
  if(uart2.available()>0){
    if(uart2.peek()!='\n'){
      uart2string+=(char)uart2.read();
    }
    else{
      uart2.read();
      Serial.print("UART2 DATA:");
      Serial.println(uart2string);
      uart2.println(uart2string);
    }
  }
    /*Serial.println("ok");
    timeClient.update();
    time1=timeClient.getFormattedTime();
    d=timeClient.getDay();
    h=timeClient.getHours();
    m=timeClient.getMinutes();
    s=timeClient.getSeconds();
    Serial.print(d);Serial.print("   ");Serial.print(h);Serial.print(":");Serial.print(m);Serial.print(":");Serial.println(s);
    delay(1000);*/ 
}