myserial.available() returns zero byte
The SoftwareSerial example code 
https://www.arduino.cc/en/Reference/SoftwareSerialAvailable
shows that the pins used as tx and rx for SoftwareSerial need to be defined using pinMode() as digital input and output.


  Example


// include the SoftwareSerial library so you can use its functions:
#include &lt;SoftwareSerial.h&gt;

#define rxPin 10
#define txPin 11

// set up a new serial port
SoftwareSerial mySerial =  SoftwareSerial(rxPin, txPin);

void setup()  {
  // define pin modes for tx, rx:
  pinMode(rxPin, INPUT);
  pinMode(txPin, OUTPUT);
  // set the data rate for the SoftwareSerial port
  mySerial.begin(9600);
}

void loop() {
  if (mySerial.available()&gt;0){
    mySerial.read();
  }
}