STM32 Timer Problem

[semmoor]

Hello ,

I have a problem in timer , how can i calculate the time in seconds from the timer register?

for example this is my program:

Code: Select all

if(first_rising_edge == 1)
{
  start_timer_3;
}
if(second_rising_edge == 1)
{
  stop_timer_3;
 time_elapsed = ?

 frequency = 1/ time_elapsed;
}

the idea is to start timer 3 if first rising edge is detected and stop it if second rising edge is detected then
calculate the period in seconds from the value in timer 3.

i tried many times but i keep getting wrong values.

this is the configurations of my MCU MINI-M4 for STM32 :

MCU: STM32F415RG

MCU running: 60Mhz
timer_3 prescalar is : 1
timer_3 generates an interrupt every : 65535

Best,
Sameer

[filip]

Hi,

Have you tried using Timer Calculator for the correct timer calculations ?
https://www.mikroe.com/timer-calculator

Regards,
Filip.

[semmoor]

I used timer calculator but the result is not correct it takes longer time than
What i need for the toggling an LED.

I'm using mikroprogrmmer for stm32. What is the correct scheme for editing the settings?
Because i think the problem is in configurations of the mcu.

[filip]

Hi,

Please find the config scheme in the attachment.

Regards,
Filip.

[semmoor]

Thank ,

So how can i get the time from the 16bit register?

Best,
Sameer

[filip]

Hi,

you can set up a timer that will be triggered upon desired amount of time (e.g. 1 second) and then increment a variable so you know that 1 second has passed.

Regards,
Filip.