int inChar;
char sData[50]; //we make a 50 byte character array to hold incoming data
String sMessage = ""; // String that will hold the complete message
boolean msg_complete = false; // Flag that when true the message is complete
int bytes_received = 0; // Character counter of received bytes

void setup() {
  Serial.begin (115200);
  Serial.println("MATRICULA MRDP22230");
}

void loop(){
  // put your main code here, to run repeatedly:
  if(Serial.available()){ // Something in the Serial input buffer?
    while (Serial.available() > 0){ // While there's somethig
      inChar = Serial.read(); // Read each character in the buffer
      if (inChar == '\n') { // '\n' en of line "Carriage Return"
        sData[bytes_received] = 0; // Null character ends the String
        msg_complete = true; // Message is complete
        bytes_received = 0; // re-initialice character
      } else { // Message NOT complete
        sData[bytes_received] = inChar; // Append character
        bytes_received++; // increase char count
      }  
    }
    if (msg_complete){ // Only if message is complete
      sMessage = String(sData); // Convert to String
      Serial.print ("MATRICULA MRDP22230");
      Serial.println (sMessage) ; // Show it
      if (sMessage == "one"){ // compare to first known mssg
         Serial.println("Process #1");
     } else if (sMessage == "two") { // compare to second known mssg
         Serial.println("Process #2");
     } else if (sMessage == "three"){ // compare to third known mssg
         Serial.println("Process #3");
     } else {
        Serial.println("Dont understand the message!");
     }
     msg_complete = false; // Ready to read next message
  }
 }
}