For C++ you'd need to use a file extension suitable for C++, i.e. *.cpp or *.cc.
In addition, i'd use the C++ headers, e.g. <stdlib.h> becomes <cstdlib>, <stdio.h> becomes <cstdio> and so on.
What's the exact error message?
For C++ you'd need to use a file extension suitable for C++, i.e. *.cpp or *.cc.
What's the exact error message?
arne-mertz.de
embeddedartistry.com
#include <stdlib.h>
#include <stdio.h>
#include <unistd.h>
#include <libgpio.h>
int main(int argc, char **argv)
{
gpio_handle_t handle;
handle = gpio_open(0);
gpio_config_t cfg;
cfg.g_pin=31;
gpio_pin_config(handle, &cfg);
printf("Pin %d: \"%u\"\n", cfg.g_pin, cfg.g_flags);
};gpio_close(handle); after your're done. See gpio_close(3).
github.com
Mo is also active on the FLTK mailing list.Thanks for the assistance. I have researched wrappers and bindings and wondered about the cfltk project:
cfltk/examples/counter.c at main · MoAlyousef/cfltk
C Bindings for FLTK. Contribute to MoAlyousef/cfltk development by creating an account on GitHub.
That was over my head. Because of it I started on the W3C C++ tutorial but got bored quick.
You could use an own C++ wrapper class and wrap the C API of libGPIO to simplify things or just use it directly.
#include <sys/types.h>
#include <err.h>
#include <libgpio.h>
class GPIOWrapper
{
public:
// constructor opens the handle
GPIOWrapper()
{
this->handle = gpio_open(0);
}
// destructor closes the handle
~GPIOWrapper()
{
gpio_close(this->handle);
}
// an example wrapper method
gpio_config_t getConfig(int pin)
{
gpio_config_t cfg;
cfg.g_pin = pin;
gpio_pin_config(this->handle, &cfg);
return cfg;
}
private:
// the handle
gpio_handle_t handle;
};void fltkButtonCallback()
{
// instance of wrapper class
GPIOWrapper gpio;
// use wrapper method
gpio_config_t config = gpio.getConfig(32);
}I think the easiest path at this point is for you to push your code to some public place where we can all look at it and provide suggestions.
lib/crtend.o /usr/lib/crtn.o
ld: error: undefined symbol: mainIn my head I cant help wondering if this is not just a matter of choice.
I did not provide a main function which of course is neccessary for every C/C++ program.
The main function should be in a C++ source file since you want to write a C++ program.
Depends on if you have a translation unit for the wrapper or not.
I appreciate that. I was thinking more along the lines of a text box but button would be better for refreshing. Maybe more work than simple text box.
c++ -v -o gpiowrap gpiowrap.cpp -I/usr/local/include -I/user/include -L/usr/local/libIn C++, 'this' pointer is an implicit pointer available inside all non-static member methods of a class, and it always points to the current object that called the method. You can omit it, but for me it feel cleaner to have it. This way, I can immediately see that the variable belongs to the class.
This is what i would do. Having a reusable wrapper for each C library.
Yes.
