cancel
Showing results for 
Search instead for 
Did you mean: 

I am having trouble with timers on STM32F1xx series specifically. I can get PWM to work but no matter how the TIM_TimeBaseInitTypeDef structure is defined, the frequency is 1.1KHz. It appears that the prescaler is divide by 64k. What's happening?

WSchi
Associate

SYS_RC TIMER_setup(void)

{

   TIM_TimeBaseInitTypeDef      TIMER_BaseInitStruct;

   TIM_OCInitTypeDef         TIMER_OCInitStruct = {0, };

   GPIO_InitTypeDef         GPIO_InitStruct;

   RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOB, ENABLE);

   RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM4, ENABLE);

   GPIO_InitStruct.GPIO_Pin = GPIO_Pin_6 | GPIO_Pin_7;

   GPIO_InitStruct.GPIO_Mode = GPIO_Mode_AF_PP;

   GPIO_InitStruct.GPIO_Speed = GPIO_Speed_50MHz;

   GPIO_Init(GPIOB, &GPIO_InitStruct);

   TIMER_BaseInitStruct.TIM_Prescaler = 19;

   TIMER_BaseInitStruct.TIM_Period = 10;

   TIMER_BaseInitStruct.TIM_ClockDivision = TIM_CKD_DIV1;

   TIMER_BaseInitStruct.TIM_CounterMode = TIM_CounterMode_Up;

   TIMER_BaseInitStruct.TIM_RepetitionCounter = 0;

   TIM_TimeBaseInit(TIM1, &TIMER_BaseInitStruct);

   TIM_Cmd(TIM4, ENABLE);

   TIMER_OCInitStruct.TIM_OCMode = TIM_OCMode_PWM1;

   TIMER_OCInitStruct.TIM_Pulse = 285;

   TIMER_OCInitStruct.TIM_OutputState = TIM_OutputState_Enable;

   TIM_OC1Init(TIM4, &TIMER_OCInitStruct);

   TIM_OC1PreloadConfig(TIM4, TIM_OCPreload_Enable);

   TIMER_OCInitStruct.TIM_OCMode = TIM_OCMode_PWM1;

   TIMER_OCInitStruct.TIM_Pulse = 570;

   TIMER_OCInitStruct.TIM_OutputState = TIM_OutputState_Enable;

   TIM_OC2Init(TIM4, &TIMER_OCInitStruct);

   TIM_OC2PreloadConfig(TIM4, TIM_OCPreload_Enable);

   return (RC_OKAY);

}

0 REPLIES 0