PS, after upon testing, I found there is a Library update, there was a 32F303CB.fcdx update package inside.
I have tried it, still not work. So I replace it with the one you put in you message.
Just let you know:
What you have posted --- OK!
The one in Library update --- NG!

Br, Deqiang

Hi, I've bought an STM32F303 development board to play with. I've not had any issues with the timer interrupt. However, my testing has thrown up an issue with the 32F303CB FCD, the config section is missing the HSE source divider parameter. This means it would be easy to accidentally overclock the ...

I'm not using anything at the moment :roll: Despite retirement, I don't seem to have much spare time. I've used 205/405 in the past, but don't have any of that hardware now. So I wouldn't let that sway you. btw. Did you do any tests at a lower APB1 timer clock speed? I did wonder if you are getting...

Hello, Yes it looks like the timed interval component has a problem on STM32 we will investigate. For now is it possible for you to just use the timer interrupt instead. I have attached a modified version of your program as an example for you. You will probably need to go into the properties of the...

medelec35 wrote: ↑

Tue Aug 12, 2025 12:54 pm

Thank you for reporting this.
I have replicated this issue and I will investigate.

Hello,

Is there some improvement?

Br, Deqiang

Thanks for the feedback. Although I can't see what the problem might be, especially if the main loop LED flash is correct in all cases, which implies that the system clock is setup OK and running as expected. Why the timer interrupt should differ between using HSE and HSI as a source is eluding me ...

Hello,

Is it possible to add STM32F1xx series chips into the support list?
They are so much popular for common use.
Especially STM32F103xx series

https://www.st.com/en/microcontrollers- ... eries.html


Br, Deqiang

Thanks. So, just to confirm what I think you are reporting, with your latest program... running on HSE... The main loop flash (1 second on, 1 second off) runs OK, even when the hardware is power cycled. But the timer interrupt flash often runs much slower when power cycled, but runs OK following pr...

LeighM wrote: ↑

Tue Aug 12, 2025 12:57 pm

Thanks for the info, interesting.

What was the result of the main loop LED flash when running on HSE (crystal)?

The main loop LED flash running ok with HSE.

Br, Deqiang

Could you try a test running on HSI? (To see if it's a problem with the crystal) Might also be worth changing the main loop to give another (LED) output toggle 500ms off and on, to check what the system clock is doing. Hello, Thank you for your suggestion. I agree with you, and I have tested, the H...