STM32F0 Komparator

[Matthias H. (streno)]

Hallo,

ich versuche mich gerade an einem PWM Komparator Modul mit einem STM32F0 
Discovery.

Dazu habe ich das Komerator-Bsp. von CooCox genommen.

Laut Text läuft der Timer im PWM-Modus, sobald aber der 
Nichtinvertierende Eingang(PA3) größer als der Invertierende 
Eingang(PA2) wird, geht der Ausgang von PA8(PWM-Timer) auf 0. Bei mir 
wird der Ausgang aber 1. Ich habe mich wirklich intensiv mit dem 
Beispiel beschäftigt, alle möglichen Parameter geändert, aber finde 
nicht den Fehler.

Hat sich jemand schonmal damit beschäftigt?

Ich poste mal den Code.

Vielleicht hat jemand eine Idee?

void PWMSignalControl(void)
{

  /* TIM1 channels Configuration in PWM mode */
  TIM_Config();

  /* COMP2 Configuration */
  COMP_Config();

  /* Infinite loop */
  while (1)
  {
  }
}
void TIM_Config(void)
{
 
  TIM_BDTRInitTypeDef     TIM_BDTRInitStructure;
  TIM_OCInitTypeDef       TIM_OCInitStructure;
  TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
  GPIO_InitTypeDef        GPIO_InitStructure;

  /* GPIOA clock enable */
  RCC_AHBPeriphClockCmd(RCC_AHBPeriph_GPIOA, ENABLE);

  /* TIM1 channels pin configuration:
       TIM1_CH1 -> PA8
  */
  GPIO_StructInit(&GPIO_InitStructure);
  GPIO_InitStructure.GPIO_Mode  = GPIO_Mode_AF;
  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
  GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
  GPIO_InitStructure.GPIO_PuPd  = GPIO_PuPd_UP;
  GPIO_InitStructure.GPIO_Pin   = GPIO_Pin_8;
  GPIO_Init(GPIOA, &GPIO_InitStructure);

  /* Enable Alternate function on PA8 to be controlled by TIM1 */
  GPIO_PinAFConfig(GPIOA, GPIO_PinSource8, GPIO_AF_2);

  /* TIM1 clock enable */
  RCC_APB2PeriphClockCmd(RCC_APB2Periph_TIM1, ENABLE);

  /* Time Base configuration */
  TIM_TimeBaseStructInit(&TIM_TimeBaseStructure);
  TIM_TimeBaseStructure.TIM_Prescaler = 0;
  TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
  TIM_TimeBaseStructure.TIM_Period = 480;
  TIM_TimeBaseStructure.TIM_ClockDivision = 0;
  TIM_TimeBaseStructure.TIM_RepetitionCounter = 0;
  TIM_TimeBaseInit(TIM1, &TIM_TimeBaseStructure);

  /* Channel 1 Configuration in PWM mode */
  TIM_OCStructInit(&TIM_OCInitStructure);
  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 = 240;
  TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_Low;
  TIM_OCInitStructure.TIM_OCNPolarity = TIM_OCNPolarity_Low;
  TIM_OCInitStructure.TIM_OCIdleState = TIM_OCIdleState_Set;
  TIM_OCInitStructure.TIM_OCNIdleState = TIM_OCIdleState_Reset;
  TIM_OC1Init(TIM1, &TIM_OCInitStructure);

  /* Automatic Output enable, Break, dead time and lock configuration*/
  TIM_BDTRStructInit(&TIM_BDTRInitStructure);
  TIM_BDTRInitStructure.TIM_OSSRState = TIM_OSSRState_Enable;
  TIM_BDTRInitStructure.TIM_OSSIState = TIM_OSSIState_Enable;
  TIM_BDTRInitStructure.TIM_LOCKLevel = TIM_LOCKLevel_1;
  TIM_BDTRInitStructure.TIM_DeadTime = 11;
  TIM_BDTRInitStructure.TIM_Break = TIM_Break_Enable;
  TIM_BDTRInitStructure.TIM_BreakPolarity = TIM_BreakPolarity_High;
  TIM_BDTRInitStructure.TIM_AutomaticOutput = TIM_AutomaticOutput_Enable;
  TIM_BDTRConfig(TIM1, &TIM_BDTRInitStructure);

  /* Main Output Enable */
  TIM_CtrlPWMOutputs(TIM1, ENABLE);

  /* TIM1 counter enable */
  TIM_Cmd(TIM1, ENABLE);
}

/**
  * @brief  Configures COMP2: PA3 as COMP2 non inverting input
  *                           VREFINT as COMP2 inverting input
  *                           and COMP2 output to TIM2 BKIN.
  * @param  None
  * @retval None
  */
void COMP_Config(void)
{
  
  COMP_InitTypeDef        COMP_InitStructure;
  GPIO_InitTypeDef        GPIO_InitStructure;
  /* GPIOA Peripheral clock enable */
  RCC_AHBPeriphClockCmd(RCC_AHBPeriph_GPIOA, ENABLE);

  /* Configure PA3 in analog mode: PA3 is connected to COMP2 non inverting input */
  GPIO_StructInit(&GPIO_InitStructure);
  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_3;
  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AN;
  GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL;
  GPIO_Init(GPIOA, &GPIO_InitStructure);

  /* COMP Peripheral clock enable */
  RCC_APB2PeriphClockCmd(RCC_APB2Periph_SYSCFG, ENABLE);

  /* COMP2 config */
  COMP_StructInit(&COMP_InitStructure);
  COMP_InitStructure.COMP_InvertingInput = COMP_InvertingInput_VREFINT;
  COMP_InitStructure.COMP_Output = COMP_Output_TIM1BKIN;
  COMP_InitStructure.COMP_Hysteresis = COMP_Hysteresis_No;
  COMP_InitStructure.COMP_Mode = COMP_Mode_HighSpeed;
  COMP_InitStructure.COMP_OutputPol =  COMP_OutputPol_NonInverted;
  COMP_Init(COMP_Selection_COMP2, &COMP_InitStructure);

  /* Enable COMP2 */
  COMP_Cmd(COMP_Selection_COMP2, ENABLE);

[Ingo Less (Gast)]

Matthias H. schrieb:
> TIM_OCInitStructure.TIM_OCIdleState = TIM_OCIdleState_Set;
>   TIM_OCInitStructure.TIM_OCNIdleState = TIM_OCIdleState_Reset;
Hier legst du die Pegel fest, die beim Braek anliegen sollen. Somit ist 
einer der Ausgänge high und der andere low.

[Matthias H. (streno)]

Ingo Less schrieb:
> Matthias H. schrieb:
>> TIM_OCInitStructure.TIM_OCIdleState = TIM_OCIdleState_Set;
>>   TIM_OCInitStructure.TIM_OCNIdleState = TIM_OCIdleState_Reset;
> Hier legst du die Pegel fest, die beim Braek anliegen sollen. Somit ist
> einer der Ausgänge high und der andere low.

Okay ich habe es.
Falls es jemanden interessiert, der richtige Code für die Timer 
Initialisierung lautet:

  /* Channel 1 Configuration in PWM mode */
  TIM_OCStructInit(&TIM_OCInitStructure);
  TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1;
  TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
  TIM_OCInitStructure.TIM_OutputNState = TIM_OutputNState_Enable;
  TIM_OCInitStructure.TIM_Pulse = 240;
  TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High;
  TIM_OCInitStructure.TIM_OCNPolarity = TIM_OCNPolarity_Low;
  TIM_OCInitStructure.TIM_OCIdleState = TIM_OCIdleState_Set;
  TIM_OCInitStructure.TIM_OCNIdleState = TIM_OCNIdleState_Reset;
  TIM_OC1Init(TIM1, &TIM_OCInitStructure);