Menu on Serial Monitor

Question

I'm trying to make a menu through serial monitor, but it always on a infinite loop... My question is where i call this function? On Setup or on Loop?

The menu:

 int controle_opera = 0;
 void menu() {
 int i = -1;
 do {
 char opcao = '0円';
 Serial.println("\nQual operação deseja realizar?");
 Serial.println("\n1 - Cadastro");
 Serial.println("\n2 - Validação");
 Serial.println("\n3 - Deletar");
 Serial.println("\n4 - Apagar database");
 if (Serial.available()) {opcao = Serial.read();}
 switch (opcao) {
 case '1': controle_opera++;
 i++;
 break;
 case '2': controle_opera += 2;
 i++;
 break;
 case '3': controle_opera += 3;
 i++;
 break;
 case '4': controle_opera += 4;
 i++;
 break;
 default: Serial.println("Opção desconhecida, tente novamente!");
 delay(100);
 break;
 }
 } while(i != 0);
}

• Majenko: You would run your menu from loop() - but not that menu since it is fundamentally flawed in many many ways.
• Zoey: Even when there're many others functions that need, for example, the value of "controle_opera"? There's any easy way to correct this menu?
• Majenko: Learn how to write a proper finite state machine.
• ElectronSurf: @Mdsp take a look at this link for a correct format of switch case example.
• neu-rah: github.com/neu-rah/ArduinoMenu works over serial