int main(void){
RCC->IOPENR |= RCC_IOPENR_GPIOAEN; // Enable clock for GPIO Port A
GPIOA->MODER &= ~(0b11 << (2*1)); //set pin2 as input
GPIOA->PUPDR |= (0b10 << (2*1)); //select pull down for pin 2
// ***** pin 1 config *******
GPIOA->MODER &= ~(0b11 << (2*0));
GPIOA->MODER |= (0b01 << (2*0));
GPIOA->OTYPER &= ~0b1;
while(1){
// if(GPIOA->IDR & ~(0b10))
if(GPIOA->IDR & 1 << 1){
GPIOA->ODR ^= 1;
}
}
return 0;
}