Curious as always, I thought I'd spend some time playing with C++ on my current project. This has an xMega chip.
I found "Jax Coder's" page at http://jaxcoder.com/Projects.asp... and blinking an LED seemed an appropriate first task for making a class.
I had to adapt his class to xMega by adapting the class:
CBlink.h
/*
* CBlink.h
*
* Created: 7/20/2014 2:41:00 PM
* Author: Tom
*/
#ifndef CBLINK_H_
#define CBLINK_H_
class CBlink
{
public:
//Constructor with the last parameter set to false as default.
CBlink(volatile PORT_t * port, uint8_t pin, bool initiallyLit=false);
bool IsLedLit() { return m_isLedLit; }
void SetLitState(bool state);
void ToggleLitState();
private:
bool m_isLedLit;
volatile PORT_t * m_port;
uint8_t m_pin;
};
#endif /* CBLINK_H_ */
(Curiously, the clipboard has been working of late. Perhaps fixed by an MS update?)
CBlink.c
/* * CBlink.cpp * * Created: 7/20/2014 2:41:16 PM * Author: Tom */ #include#include "CBlink.h" CBlink::CBlink(volatile PORT_t * port, uint8_t pin, bool initiallyLit/* =false */) { //Set the port addresses for the DDR and PORT values m_port = port; //Set the DDRn.pin as output m_port->DIRSET = _BV(pin); m_pin = pin; m_isLedLit = initiallyLit; //Set initial state of the LED SetLitState(m_isLedLit); } void CBlink::SetLitState(bool state) { m_isLedLit = state; if (m_isLedLit) m_port->OUTCLR = _BV(m_pin); else m_port->OUTSET = _BV(m_pin); } void CBlink::ToggleLitState() { SetLitState(!m_isLedLit); }
Things went haywire when I tried to build the app, because there wasn't any _cplusplus.h Not knowing what else to do about it, I deleted the include statement, and my app builds and... egad, the led blinks!
/* * LearnC__01.cpp * * Created: 7/20/2014 2:37:23 PM * Author: Tom */ #define F_CPU 2000000 #include#include //#include "_cplusplus.h" #include "CBlink.h" int main(void) { CBlink blink(&PORTA,3); while(1) { blink.ToggleLitState(); _delay_ms(2000); } }
He includes what looks like the _cplusplus.h file, so I added that:
/*
* _cplusplus.h
*
* Created: 7/20/2014 3:22:50 PM
* Author: Tom
*/
#ifndef _CPLUSPLUS_H_
#define _CPLUSPLUS_H_
/*
This is applicable if using virtual inheritance.
*/
__extension__ typedef int __guard __attribute__((mode (__DI__)));
extern "C" int __cxa_guard_acquire(__guard *);
extern "C" void __cxa_guard_release (__guard *);
extern "C" void __cxa_guard_abort (__guard *);
int __cxa_guard_acquire(__guard *g) {return !*(char *)(g);};
void __cxa_guard_release (__guard *g) {*(char *)g = 1;};
void __cxa_guard_abort (__guard *) {};
/*
This is applicable if using pure virtual inheritance.
*/
extern "C" void __cxa_pure_virtual(void);
void __cxa_pure_virtual(void) {};
/*
Operators required for C++
*/
void* operator new(size_t size);
void operator delete(void* size);
void * operator new(size_t size)
{
return malloc(size);
}
void operator delete(void* ptr)
{
free(ptr);
}
#endif /* _CPLUSPLUS_H_ */
But when I try to include this code I don't understand, I get errors I don't understand. Strange, how that works, uMM?
Under Operators required for C++
/*
Operators required for C++
*/
void* operator new(size_t size);
The error points to size_t and says two things:
"size_t was not declared in this scope" which is pretty obvious that it doesn't know what a size_t is.
Um, so is there something more I need to know about using C++ in studio 6.2?
I believe it's now time for a Sunday Afternoon walk.
