KED/libraries/examples/interrupt/main.c

#include "main.h"
#include "delay.h"
#include "deviceSetup.h"
#include "usart.h"
#include "ascii.h"
#include "timer.h"
#include "i2c.h"
#include "pin.h"

#include "stm32f042x6.h"
#include "hardwareDescription.h"

volatile uint8_t led_on;

void setup();
#if 0
void EXTI0_1_IRQHandler(void)
{
	if(EXTI->PR & EXTI_PR_PIF1) {
		// clear flag
		EXTI->PR |= EXTI_PR_PIF1;
		led_on = !led_on;
	}
}

void risingEdgeInterruptPinA1()
{

	// https://controllerstech.com/external-interrupt-using-registers/
		
	pinConfig(pinA1, input, def_stage, pullDown, def_speed);

	// Connect
	RCC->APB2ENR |= RCC_APB2ENR_SYSCFGEN;
	SYSCFG->EXTICR[1] &= ~SYSCFG_EXTICR1_EXTI1_Msk;
	SYSCFG->EXTICR[1] |= SYSCFG_EXTICR1_EXTI1_PA;

	// Interrupt mask register
	EXTI->IMR |= EXTI_IMR_IM1;
	
	// rising trigger selection
	EXTI->RTSR |= EXTI_RTSR_RT1;
	
	NVIC_SetPriority (EXTI0_1_IRQn, 0);	
	NVIC_EnableIRQ(EXTI0_1_IRQn);	

	while(1)
	{
		if(led_on){
			pinWrite(pinB3,1);
		} else{
			pinWrite(pinB3,0);
		}
	}
}
#endif

void TIM2_IRQHandler(){
    /* Check what type of event occurred */
    if (TIM2->SR & TIM_SR_UIF)
    {
        /* Clear the interrupt even flag. CPU will only respond to new flags thereafter */
        TIM2->SR &= ~TIM_SR_UIF;
		pinToggle(pinB3);
	}
}


void LEDtoggleOnTimer2underflow()
{
	/*
	//timerInitCounter(timer_2, 0xFFFF, 0, upCounting);
	
	// reset timer 2 periperal
	RCC->APB1RSTR |= RCC_APB1RSTR_TIM2RST;
	
	//while(RCC->APB1RSTR & RCC_APB1RSTR_TIM2RST);

	// enable timer 2 peripheral
	RCC->APB1ENR |= RCC_APB1ENR_TIM2EN;

	// only allow under-/overflow interrupts
	TIM2->CR1 |= TIM_CR1_URS;

	// set to count down mode
	TIM2->CR1 |= TIM_CR1_DIR;

	// set clock prescaler	
	TIM2->PSC = 0xFFFF;

	// set outo reload value	
	TIM2->ARR = 0xFFFFFFFF;
	
	//TIM2->EGR |= TIM_EGR_UG;

	// Enable Update Interrupt
	TIM2->DIER |= TIM_DIER_UIE;	

	// reset status register
	TIM2->SR = 0;

	//NVIC_SetVector(TIM2_IRQn, (uint32_t)&TIM2_IRQHandler);
	NVIC_SetPriority(TIM2_IRQn,3);
	NVIC_EnableIRQ(TIM2_IRQn);

	// timer enable	
	TIM2->CR1 |= TIM_CR1_CEN;

	//timerSart(timer_2);

	while(1)
	{
		if(TIM2->CNT > 0xFFFF) {
			pinWrite(pinB3,1);
		} else {
			pinWrite(pinB3,0);
		}
		
		if(led_on){
			pinWrite(pinB3,1);
		} else{
			pinWrite(pinB3,0);
		}
		
	}
	*/
#if 0
	// example based on
	// https://alsaibie.github.io/me319/prelabsextra/lab4extra/
	/* Enable Timer 2 peripheral */
	RCC->APB1ENR |= RCC_APB1ENR_TIM2EN;
	/* Default APB1 speed is 16MHz. Scale Timer 2 to 20kHz */
	//TIM2->PSC = (uint32_t)(16E6 / 20E3) - 1;
	TIM2->PSC = (8E6 / 20E3) - 1 ;
	/* Disable Timer*/
	TIM2->CR1 = 0;
	/* Reinitialize counter and update registers */
	TIM2->EGR = TIM_EGR_UG;
	/* 1000 Counts at 20kHz => 20Hz IRQ */
	//TIM2->ARR = 1000 - 1;
	TIM2->ARR = 10000-1;
	/* Enable hardware interrupts */
	TIM2->DIER |= TIM_DIER_UIE;
	/* Start Timer */
	TIM2->CR1 |= TIM_CR1_CEN;
#endif

	timerInitCounter(timer_2,(8E6/20E3)-1,10000-1,upCounting);

	//TIM2->EGR = TIM_EGR_UG;
	TIM2->DIER = TIM_DIER_UIE;

	timerSart(timer_2);
	
	NVIC_SetPriority(TIM2_IRQn, 2);
	NVIC_EnableIRQ(TIM2_IRQn);
	
	while(1)
	{
	}
}

int main(int argc, char *argv[])
{
	setup();

	LEDtoggleOnTimer2underflow();
	while(1);

	return 1;
}

void setup()
{
	uint8_t i = 0;

	delayInitMs(8000000, 1000); // Clock Freq and Divider for ARM library 
	
	pinConfig(pinB3, output, pushPull, def_res, def_speed);
	pinConfig(pinA0, input, def_stage, pullDown, def_speed);	
	
	setupInit(); // This is the sescond call of System init the assebly start code is calling it before the main.	
	
	usartInit(	usart2, 
				pinA2, 
				pinA15,
				115200,
				eight, 
				NO_PARITY_CTRL,
				noFlowControl); 

	//clears screen and send the wellcome messgae
	print_Usart(usart2, ASCII_clear); 
	print_Usart(usart2, "Hello to our KED project\n\r"); 
	

	//blinks 10 times to indicate the sicsessfull init if the device
	for(i = 0 ; i < 10 ; i++) {
		delayMs(100); 
		pinToggle(pinB3);
		delayMs(100); 
	}

	pinWrite(pinB3,0);
}