When you create a new Renesas project for an RX device, you can choose C++. Let's try it out with an object oriented blinky.
For simplicity, I'm creating one class: an output pin class called io::O. It can drive a pin high and low. You assign a pin at creation time. You can drive it by assigning true or false to it:
#include "O.h"
int main(void) {
bool state = true;
io::O led(GPIO_PORT_H_PIN_2); // initialise the output pin for the LED.
while(1) {
led = !led;
// silly wait
for (int i = 0; i < 10000000; i++) {};
led != led;
// silly wait
for (int i = 0; i < 10000000; i++) {};
}
return 0;
}
Class O
header: O.h
#ifndef O_H_
#define O_H_
extern "C" {
#include "r_gpio_rx_if.h"
}
namespace io {
typedef gpio_port_pin_t pin_t;
class O {
public:
O(pin_t pin);
virtual ~O();
O &operator= (O &rhs);
O &operator!= (O &rhs);
O &operator= (bool high);
operator bool() const;
protected:
pin_t pin;
};
} // namespace io
#endif /* O_H_ */
implementation: O.cpp
#include <O.h>
using namespace io;
O::O(pin_t pin): pin(pin) {
}
O::~O() {
}
O &O::operator= (bool high) {
R_GPIO_PinWrite(this->pin, (gpio_level_t)high);
return *this;
}
O &O::operator!= (O &rhs) {
R_GPIO_PinWrite(this->pin, (gpio_level_t)!((bool)rhs));
return *this;
}
O::operator bool() const {
gpio_level_t l = R_GPIO_PinRead(this->pin);
return (bool) l;
}
When you run this, you have your usual blinky. I tried to make the code very simple, with just a little bit of OO encapsulation. A proof that it can be done.
mbed fans may see similarities to the DigitalXXX classes. It was definitely an inspiration, although I didn't port their code. (I've done that in the past for another controller family).
The attached e² studio project is precompiled, using GCC and the rx23e-a starter kit board. It can be used with CC-RX and any RX controller.
FIT objects used: r_bsp (board startup), Config_PORT (pin setup) and r_gpio_rx (gpio API).
rx23ea_thermocouple_cpp_gcc_20230721.zip
