Difference between revisions of "STM32F107VC/timer2"

Revision as of 10:18, 11 October 2016

This sourrce code enables timer2 and initializes it for 10 interrupts pr. second. <source lang=c> /*----------------------------------------------------------------------------*

* Name:    timer.c /HeTh@mercantec.dk                                                           *
* Purpose: Initialize TIM2 and enable IRQHandler for TIM2                    *
* Alias:   Driver for TIM2                                                   *
* Function to be called to initialize TIM2:  timer_init()                    *
*----------------------------------------------------------------------------*/

1. include "stm32f10x.h"
2. include "Board_LED.h"

/*

* TIM_DIER_UIE   == 1
* TIM_CR1_CEN   == 1
*/

/*----------------------------------------------------------------------------

* TIM2 initializer 'timer_init': used to initialize TIM2
*---------------------------------------------------------------------------*/

void timer_init() {

  // Enable "timer 2" clock   (RCC->APB1ENR bit 0 = 1)
  RCC->APB1ENR |= 1;

  // Setting prescale value (72.000.000 / 7200 = 10000 Hz) (Side 403 Ref Manual)
  TIM2->PSC = 7200 - 1;
  
  // Autoload Register 10000 Hz - 1 (it starts at 0) (Side 354 Ref Manual)
  TIM2->ARR = 1000 - 1;
  
  // Enable IRQ interrupt for TIM2
  NVIC_EnableIRQ(TIM2_IRQn);
  
  // Enable interrupt on update
  TIM2->DIER |= TIM_DIER_UIE; // TIM_DIER_UIE = 1
  
  // Enable Counter     (TIM2_CR1 bit 0 = 1)
  TIM2->CR1 |= TIM_CR1_CEN; // TIM_CR1_CEN = 1
  

}

/*----------------------------------------------------------------------------

* TIM2 IRQHANDLER 'TIM2_IRQHandler': run when timer interrupts.
*---------------------------------------------------------------------------*/

void TIM2_IRQHandler(void) __irq{

 // Resets the IRQ Handler

static uint8_t ledState=0;

 TIM2->SR = 0;

if ( ledState == 0 ) { LED_On(1); ledState=1; } else { LED_Off(1); ledState=0; } } </lang>