code for blink an led with systick timer

[AKhan.17]

i made this code to blink an led with systick time but it does not work can you please correct this. i am using stm32l152rc discovery board.

#include "stm32l1xx.h"

while {

  if (SysTick->CTRL |= SysTick_CTRL_COUNTFLAG == 0)

   {

   GPIOB->BSRRH |= GPIO_BSRR_BS_6; 

   }

  else {

   GPIOB->BSRR |= GPIO_BSRR_BR_6;

   }

}

 int main(void)

 {

 RCC->AHBENR |= RCC_AHBENR_GPIOBEN;

 GPIOB->MODER &= ~GPIO_MODER_MODER6;

 GPIOB->MODER |= GPIO_MODER_MODER6_0;

 GPIOB->OTYPER &= -(GPIO_OTYPER_OT_6);

 GPIOB->OSPEEDR &= ~GPIO_OSPEEDER_OSPEEDR6;

 GPIOB->PUPDR &= ~GPIO_PUPDR_PUPDR6;

 GPIOB->BSRRL = GPIO_BSRR_BR_6;

 SysTick->CTRL = 0;

 SysTick->LOAD = 1599999;

 SysTick->VAL = 0;

 SysTick->CTRL = 7;

 }

[Tesla DeLorean]

Your presentation style is confusing.

What's the while() loop floating above main()?

Why is the |= in the if statement?

You should just do an assignment for BSRRH/BSRR, not OR it

The main() routine should not exit

Try using a debugger

[AKhan.17]

thank you very much Mr Clive for your hints but this time can you please rewrit the above code and send it to me, i would greatly appreciate. I am just a beginner and you are an expert.

arif from canada

[e-mail]

[AKhan.17]

#include"stm32l1xx.h"

int main(void)

   {

 RCC->AHBENR |= RCC_AHBENR_GPIOBEN;

 GPIOB->MODER &= ~GPIO_MODER_MODER6;

 GPIOB->MODER |= GPIO_MODER_MODER6_0;

 GPIOB->OTYPER &= -(GPIO_OTYPER_OT_6);

 GPIOB->OSPEEDR &= ~GPIO_OSPEEDER_OSPEEDR6;

 GPIOB->PUPDR &= ~GPIO_PUPDR_PUPDR6;

 void delay_ticks(unsigned ticks)

 {

  SysTick->LOAD = 319999;

  SysTick->VAL = 0;

  SysTick->CTRL = 5;

   while(1)

   (( SysTick->CTRL &= SysTick_CTRL_COUNTFLAG) == 1);

    SysTick->CTRL = 0;

   }

    GPIOB -> BSRRL|= GPIO_BSRR_BS_6;// turn led on

    void delay_s(unsigned ms)

    {

      delay_ticks(1000 * (32000000 / 8) );

    }

    GPIOB ->BSRRH |= GPIO_BSRR_BR_6; // turn off delay

    void delay_s(unsigned ms)

    {

      delay_ticks(1000 * (32000000 / 8) );

    }

  }

i made this code for blinking an led with systick timer for a a delay of one second. can anyone make correction in it because led just lights up but does not turn off

[henry.dick]

"can you please correct this."

your code is too far from working and reflects a complete lack of understanding, both from a hardware and software perspective.

the flow would be something like this:

1. set the pin to output;
2. set the systick to overflow at a given interval;
3. while (1) {
4. if systick overflow, reset the flag and flip the led pin;
5. }

now you just need to implement the few blocks above.

[AKhan.17]

i am doing point ( suggestion ) no 4 like this. Sir, i am just a beginner not an expert like you.

Is this correct ?

if (( SysTick->CTRL &= SysTick_CTRL_COUNTFLAG) == 1);

 SysTick->CTRL = 0;

{ GPIOB -> BSRRL|= GPIO_BSRR_BS_6;// turn led on

}