int motorPin = 9;   //For PWM signal
int mspeed = 0;    // initializing motor speed
int mStep = 15;    //Steps for increasing speed from 0 to 255


void setup()
{
  pinMode(motorPin,OUTPUT);
  Serial.begin(9600);
  Serial.println("Vacuum pump pressure testing using code");
}


void loop()
{ 
   analogWrite(motorPin, mspeed);   // Writing At pin 9 ( Speed initially 0)


   Serial.print("Speed : ");
   Serial.println(mspeed);
   mspeed = mspeed+mStep;
   if(mspeed <=0 || mspeed >=255)
{ 
  mStep = -mStep;
}
delay(500);
}