ESP8266 and Arduino serial communication

1. The wiring is as follows:

CH340 ESP8266 Arduino DataPin
TXD -> URXD　　　　13
RXD -> UTXD　　　　12
3.3V -> 3.3V　　　　br> 3.3V -> CH_PD　　　 3.3V
GND -> GND　　　　 GND

2. Write code

#include 

SoftwareSerial mySerial(13, 12); // RX, TX

void setup () {
 Serial.begin(115200); 
 Serial.println("Hello, serial!");

 // set the data rate for the SoftwareSerial port
 mySerial.begin(115200);
 mySerial.println("AT< span style="color: #800000">");
}

void loop() {// run over and over
 if (mySerial.available()) {
 Serial.write(mySerial. read());
 }
 if (Serial.available( )) {
 mySerial.write(Serial.read());
 }
} Set the terminator to NL and CR, the baud rate is 115200, and you will receive it when you send AT Reply OK

#include 

 SoftwareSerial mySerial(13, 12); // RX, TX

void setup() {
 Serial.begin(115200); < span style="color: #000000">
 Serial.println("Hello ,serial!");

 // set the data rate for the SoftwareSerial port
 mySerial.begin(115200);
 mySerial.println("< /span>AT");
}

< span style="color: #0000ff">void loop() {// run over and over
 if (mySerial.available()) {
 Serial. write(mySerial.read());
 }
 if ( Serial.available()) {
 mySerial.write(Serial.read());
 }
} Set the terminator to NL and CR, set the baud rate to 115200 Send AT You will receive a reply OK