How to make Arduino runs continuous routines even inside a "switch case loop".

Projects Programming
10

Program structure is easier to follow if you indent it like this

void loop()
{
  if(Serial.available()){
    ch=Serial.read();
  }

or

void loop()
{
  if(Serial.available())
  {
    ch=Serial.read();
  }

The compiler doesn't care, but my first reading of your revised code was that nothing had changed.