class GUI
{
    HardwareInterface hrdwr;
    GUI(int iHardwareEnum)
    {
        hrdwr = new HardwareInterface(iHardwareEnum);
    }
    void HardwareConnect()
    {
        hrdwr.Connect();
    }
}

public class HardwareInterface
{
    public HardwareInterface(int iHardwareSelect)
    {
        //if iHardwareSelect == Peak-CAN implement XCPApiPeak else == Serial-COM implement Serial-COM API
    }

    public void Connect()
    {
        
    }
}

public static class XCPApiPeak
{
    public static void Connect(void);

}

public static class SerialCOM
{
    public static void Connect(void);
}

namespace MyNamespace
{
    public interface IMyHardwareInterface
    {
        void Connect();
    }

    public class XCPApiPeakInterface : IMyHardwareInterface
    {
        public void Connect() => throw new System.NotImplementedException();
    }

    public class SerialCOM : IMyHardwareInterface
    {
        public void Connect() => throw new System.NotImplementedException();
    }

    public enum MyHardwareInterfaceType
    {
        XCPApi,
        SerialCOM
    }

    public class MyHardwareInterfaceFactory
    {
        public IMyHardwareInterface GetInstance(MyHardwareInterfaceType type) // oder enum oder whatever
        {
            switch (type)
            {
                case MyHardwareInterfaceType.XCPApi:
                    return new XCPApiPeakInterface();
                case MyHardwareInterfaceType.SerialCOM:
                    return new SerialCOM();
            }

            throw new ArgumentOutOfRangeException($"Unknown type {type}");
        }
    }
    public class MyApp
    {
        public void Sample(MyHardwareInterfaceFactory factory)
        {
            IMyHardwareInterface instance = factory.GetInstance(MyHardwareInterfaceType.XCPApi);

            instance.Connect();
        }
    }
}