Getting private bool property from method in Arduino library

Question

I'm creating my own library in arduino to controlling a pump. The library is very simple:

---

Pump.h

#ifndef Pump_h
#define Pump_h

#include "Arduino.h"

class Pump
{
  public:
    Pump(int pin);
    void Open(void);
    void Close(void);
    boolean IsOpen(void);
  private:
    int _pin;
    bool _status;
};

#endif

---

Pump.cpp

---

#include "Arduino.h"
#include "Pump.h"

Pump::Pump(int pin)
{
  pinMode(pin, OUTPUT);
  digitalWrite(pin,HIGH);
  _pin = pin;
  _status = false;
}

void Pump::Open(void)
{
  digitalWrite(_pin, LOW);
  _status = true;
}

void Pump::Close(void)
{
  digitalWrite(_pin, HIGH);
  _status = false;
}

boolean Pump::IsOpen(void)
{
  return _status;
}

---

loop()

---

#include <Pump.h>
#define PUMP1 Pump(9)

void loop() {
  BridgeClient client = server.accept(); // Get clients coming from server
  if (client) {  // There is a new request from client?
    Console.println("Client connected");
    process(client);  // Process request
    client.stop();    // Close connection and free resources.
  }
  Console.println(PUMP1.IsOpen());
  delay(50); // Poll every 50ms
}

The problem is that when I call the function IsOpen inside the loop() function of Arduino I get always false and the Pump is immediately turned off. What's wrong with my code?

Answer 1

Your PUMP1.IsOpen() simply creates a temporary object of Pump class that is immediately destroyed.

You need to create an object of Pump that live throughout the execution of program. I am not familiar with Arduino call flow, but you could achieve this with some initialization/setup method or use singleton design or for this simple use case create a global object of Pump (which I normally don't educate people and is against using such design)