char inData[64];
char inChar=-1;

void setup(){
   Serial.begin(9600);
   Serial.begin("Waiting for Raspberry Pi to send a signal...n");
}


void loop(){
    byte numBytesAvailable= Serial.available();

    // if there is something to read
    if (numBytesAvailable > 0){
        // store everything into "inData"
        int i;
        for (i=0;i<numBytesAvailable;i++){
            inChar= Serial.read();
            inData[i] = inChar;
        }

        inData[i] = '';


        Serial.print("Arduino Received: ");
        Serial.println(inData);
    }
}

import serial
ser = serial.Serial('/dev/ttyACM1',9600)
ser.write("MOVE")

Arduino Received: M
Arduino Received: O
Arduino Received: V
Arduino Received: E

Arduino Received: MOVE

import serial
ser = serial.Serial('/dev/ttyACM1',9600)
ser.write("MOVEn")

// Buffer to store incoming commands from serial port
String inData;

void setup() {
    Serial.begin(9600);
    Serial.println("Waiting for Raspberry Pi to send a signal...n");
}

void loop() {
    while (Serial.available() > 0)
    {
        char recieved = Serial.read();

        // Process message when new line character is recieved
        if (recieved == 'n')
        {
            Serial.print("Arduino Received: ");
            Serial.print(inData);

            inData = ""; // Clear recieved buffer
        }else{
            inData += recieved;
        }
    }
}

ser.write("MOVE")

ser.write("MO")
ser.write("VE")

if(Serial.available() > 0) {
     str = Serial.readStringUntil('n');
     Serial.println(str);

`String readString;

void setup() {
 Serial.begin(9600); // initialization

}

  void loop() {
  char incomingByte;
  while (Serial.available()>0) {
  delay(10);  // if the data came

   incomingByte = Serial.read(); // read byte
 //Serial.println(incomingByte);

   readString +=incomingByte;

  }
  if(readString != "")
   {
     Serial.print("arduino recived this : ");
     Serial.println(readString);

   }
   readString = "";

  }`