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STM32F103 PWM outputs wrong signal to mosfets

Question asked by karakaya.mehmet on Jul 2, 2014
hello dear forum

I drive an H bridge with STM32F103
I want that until I enable the H bridge the PWM outputs to be low
( I run below reset_motor() function until motor enabled )  
however the Upper mosfets are driven with logic 1 until I enable the motor

here is my code
please which lines to be changed how ?
thank you

void PWMinit2(void){
  
  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_6|GPIO_Pin_7;
  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_2MHz;
  GPIO_Init(GPIOC, &GPIO_InitStructure);
  
  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_7;
  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_2MHz;
  GPIO_Init(GPIOA, &GPIO_InitStructure);
  
  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0;
  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_2MHz;
  GPIO_Init(GPIOB, &GPIO_InitStructure);
  
  
/* Time Base configuration */
  TIM_TimeBaseStructure.TIM_Prescaler = 99;
  TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
  TIM_TimeBaseStructure.TIM_Period = 7200;
  TIM_TimeBaseStructure.TIM_ClockDivision = 0;
  TIM_TimeBaseStructure.TIM_RepetitionCounter = 0;
  
  TIM_TimeBaseInit(TIM8, &TIM_TimeBaseStructure);
  
  TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM2;
  TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
  TIM_OCInitStructure.TIM_OutputNState = TIM_OutputNState_Enable;
  TIM_OCInitStructure.TIM_Pulse = 6000;
  TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High;
  TIM_OCInitStructure.TIM_OCNPolarity = TIM_OCNPolarity_High;
  TIM_OCInitStructure.TIM_OCIdleState = TIM_OCIdleState_Reset;
  TIM_OCInitStructure.TIM_OCNIdleState = TIM_OCNIdleState_Reset;
  
  TIM_OC1Init(TIM8, &TIM_OCInitStructure);
  TIM_OC2Init(TIM8, &TIM_OCInitStructure);
    
  reset_motor();
    
  /* Automatic Output enable, Break, dead time and lock configuration*/
  TIM_BDTRInitStructure.TIM_OSSRState = TIM_OSSRState_Enable;
  TIM_BDTRInitStructure.TIM_OSSIState = TIM_OSSIState_Enable;
  TIM_BDTRInitStructure.TIM_LOCKLevel = TIM_LOCKLevel_OFF;
  TIM_BDTRInitStructure.TIM_DeadTime = 120;
  TIM_BDTRInitStructure.TIM_Break = TIM_Break_Disable;
  TIM_BDTRInitStructure.TIM_BreakPolarity = TIM_BreakPolarity_Low;
  TIM_BDTRInitStructure.TIM_AutomaticOutput = TIM_AutomaticOutput_Disable;
  
  TIM_BDTRConfig(TIM8, &TIM_BDTRInitStructure);
  
  TIM_CCPreloadControl(TIM8, DISABLE);
  TIM_ARRPreloadConfig(TIM8, ENABLE);
  
  TIM_ITConfig(TIM8, TIM_IT_Update , ENABLE);
  
  /* TIM1 counter enable */
  TIM_Cmd(TIM8, ENABLE);
  /* Main Output Enable */
  TIM_CtrlPWMOutputs(TIM8, ENABLE);
  reset_motor();
}
  
void reset_motor(void){ 
    TIM_CCxCmd(TIM8, TIM_Channel_1, TIM_CCx_Disable);
    TIM_CCxNCmd(TIM8, TIM_Channel_1, TIM_CCxN_Disable);
  
    TIM_CCxCmd(TIM8, TIM_Channel_2, TIM_CCx_Disable);
    TIM_CCxNCmd(TIM8, TIM_Channel_2, TIM_CCxN_Disable);
  
}

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