Arduino program structure

Soure: https://github.com/arduino/ArduinoCore-avr/blob/master/cores/arduino/main.cpp

#include <Arduino.h>

// Declared weak in Arduino.h to allow user redefinitions.

int atexit(void (* /*func*/ )()) { return 0; }

// Weak empty variant initialization function.

// May be redefined by variant files.

void initVariant() __attribute__((weak));

void initVariant() { }

void setupUSB() __attribute__((weak));

void setupUSB() { }

int main(void)

{

init();

initVariant();

#if defined(USBCON)

USBDevice.attach();

#endif

setup();

for (;;) {

loop();

if (serialEventRun) serialEventRun();

}

return 0;

}