Posted on September 21, 2013 at 03:40 Hi all I have a project (@my uni) due in late November and i am really stretching all possible time to see something going.
Could Someone please help me as to why this below code ISR only happens once?
Thus the Orange LED on Pin 13 flashes One tenth of a sec but the Blue one on Pin 15 which is meant to be flashing every sec isn't (ie: Stay on) i have been carefully following the code and the problem seems to be in the ISR itself, ie: it only happens once even though
(
TIM2->
EGR
|= TIM_EGR_UG
) is meant to be updating the flag every time the Counter reaches ARR value. I really don't seems to see why it isn't working can someone help me?
Many Thanks again
Regards
Entropy
/*
Timer ISR running on STM32F407VG with COIDE
Please ignore the comments were meant for other development code. Thanks
*/
#include<stdint.h>
#include<stdlib.h>
#include <stdbool.h>
#include''stm32f4xx.h''
#include''stm32f4xx_rcc.h''
#include''stm32f4xx_tim.h''
#include''stm32f4xx_gpio.h''
#include''core_cm4.h''
volatile bool Process_Task = false;
void _delay_us(uint32_t us);
void _delay_ms(uint32_t ms);
void
TIM2_IRQHandler(
void
); int main()
{
SystemInit();
GPIO_InitTypeDef
GPIO_InitStructure; GPIO_InitStructure;
RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOD,
ENABLE
);
RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2 | RCC_APB1Periph_TIM3,
ENABLE
);
GPIO_InitStructure.
GPIO_Pin
= GPIO_Pin_12 | GPIO_Pin_13| GPIO_Pin_14| GPIO_Pin_15;
GPIO_InitStructure.
GPIO_Mode
=
GPIO_Mode_OUT
;
GPIO_InitStructure.
GPIO_OType
=
GPIO_OType_PP
;
GPIO_InitStructure.
GPIO_Speed
=
GPIO_Speed_100MHz
;
GPIO_InitStructure.
GPIO_PuPd
=
GPIO_PuPd_NOPULL
;
GPIO_Init(GPIOD, &GPIO_InitStructure);
NVIC_InitTypeDef
NVIC_InitStructure;
/* Enable the TIM2
gloabal
Interrupt */ NVIC_InitStructure.
NVIC_IRQChannel
=
TIM2_IRQn
;
NVIC_InitStructure.
NVIC_IRQChannelPreemptionPriority
= 0;
NVIC_InitStructure.
NVIC_IRQChannelSubPriority
= 1;
NVIC_InitStructure.
NVIC_IRQChannelCmd
=
ENABLE
;
NVIC_Init(&NVIC_InitStructure);
/* TIM2 clock enable */
TIM2->
PSC
= 41999;
TIM2->
ARR
= 3999;
TIM2->
CNT
= 0;
TIM2->
EGR
|= TIM_EGR_UG;
TIM2->
SR
&= ~ TIM_SR_UIF;
TIM2->
CR1
|= (TIM_CR1_OPM);
// Clear the update flag
TIM2->
DIER
|= TIM_DIER_UIE;
// Enable interrupt on update event
NVIC_EnableIRQ(
TIM2_IRQn
);
// Enable TIM6 IRQ
TIM2->
CR1
|= TIM_CR1_CEN; // Enable TIM6 counter
//while (!(TIM2->SR & TIM_SR_UIF));
while
(1)
{
GPIOD->
ODR
^= 1<<13;
_delay_ms(100);
}
}
void
TIM2_IRQHandler(
void
) {
if
(TIM2->
SR
& (TIM_SR_UIF))
// If update flag is set
{ {
GPIOD->
ODR
^= 1<<15; TIM2->
SR
&= ~TIM_SR_UIF;
//Clear it.
//Process_Task = true; // Set D15 high
// GPIOD->ODR |= 1<<15; // Interrupt has been handled
//_delay_ms(15);
}
//delay_ms(15);
}
void _delay_us(uint32_t us)
{
TIM3->
PSC
= 83 ;
TIM3->ARR
= us -1 TIM3->
CNT
= 0;
TIM3->
EGR
|= TIM_EGR_UG;
TIM3->
SR
&= ~ TIM_SR_UIF;
TIM3->
CR1
|= (TIM_CR1_OPM);
// Clear the update flag
TIM3->
CR1
|= TIM_CR1_CEN;
while
(!(TIM3->
SR
& TIM_SR_UIF));
}
void _delay_ms(uint32_t ms)
{
while
( ms -- > 0) {
_delay_us(1000);
}
}
