Simple Arduino Serial comunication, with echo of entire line received and calculation of time elapsed to read entire line.

SerialEchoLineWithTime.ino

/**
 *
 * Author: Domenico Monaco
 *
 * Description: 
 *   Simple Arduino Serial comunication, with echo of entire line received
 *   and calculation of time elapsed to read entire line. This example is
 *   extension of  https://gist.github.com/kiuz/d59519e0de7677df42c3/
 *
 * Source: https://gist.github.com/kiuz/9d151fcc568201cd8297
 *
 * License: GNU v2 2014
 **/

int incomingByte = 0;    // for incoming serial data

long int timeStartCom = 0;
long int timeEndCom = 0;

long int charsIN = 0;
bool waiting = false;

String line="";

void setup() {
    Serial.begin(115200);
}

void loop() {
  
  readLine();
  
  handeShake(line);
  
  
}

void handeShake(String message){

  if(message.length!=0){
  Swerial.println("Leggo messaggio");
  }
}


void readLine(){

  // send data only when you receive data:
  if (Serial.available() > 0) {
    
    if(charsIN==(long int)0){
      
      timeStartCom = millis();
      timeEndCom = 0;
      
      waiting = false;
    }
    charsIN++;
    
    incomingByte = Serial.read();
    line = line + (char)incomingByte;
    
    delay(1); //Delay of Serial transfer
  }else{
    
    if(waiting==false){
      waiting = true;

      timeEndCom = millis();
      
      ///PRINT PREVUOUS MESSAGE 
      Serial.print("Message: ");
      Serial.println(line);
      
      Serial.print("Recived ");
      Serial.print(charsIN);
      Serial.print("chars in ");
      Serial.print(timeEndCom-timeStartCom);
      Serial.print("millis; ");
      Serial.print((float)(timeEndCom-timeStartCom)/charsIN);
      Serial.print(" mills for chars;");
      Serial.print(" ");
      Serial.print((float)charsIN/(timeEndCom-timeStartCom));
      Serial.println("char/millis;");
      Serial.println("---------------------");

      line = "";
      timeStartCom = 0;
      charsIN = (long int)0;

      Serial.println("");
      Serial.println("Waiting for message...");
      Serial.println(""); 
    }
  }
}