PWM Frequency generated

[Jess32]

Hi,

i am working on STM32F302R8Tx and i would like to have a  490 Hz PWM on Timer15 Channel2, 

attached are my configuration and my code, when i measure it , i become 491,13..Hz. what can I do to get the exact 490Hz? 

Any  Suggestions?? 

thank you!!!

 

 

[AScha.3]

Hi,

you clock at 64MHz , 

so -> 64M / 130 = 492,3kHz

divide by counter (arr) : (1005-1) -> 489,9Hz (closest you can get here)

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If you set 64M / 131  , arr (997-1) , then 490,02 Hz is possible.

[waclawek.jan]

Also, HSI is not a precise primary clock source (see datasheet for HSI specification), so there will always be some error introduced by that fact.

JW

[Jess32]

okay, thank you for your answers!!!!!