void TIM_Config(void) {

  TIM_TimeBaseInitTypeDef  TIM_TimeBaseStructure;
  TIM_OCInitTypeDef  TIM_OCInitStructure;

  // Konfiguracja TIM4
  TIM_TimeBaseStructure.TIM_Prescaler = 0;
  TIM_TimeBaseStructure.TIM_Period = 24000ul;      //czestotliwosc PWM = 3kHZ
  TIM_TimeBaseStructure.TIM_ClockDivision = TIM_CKD_DIV1;
  TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;

  TIM_TimeBaseInit(TIM4, &TIM_TimeBaseStructure);

  // Konfiguracja kanalu 3
  TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1;
  TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
  TIM_OCInitStructure.TIM_Pulse = 9600ul;          //wypelnienie = 40%
  TIM_OCInitStructure.TIM_OCPolarity=TIM_OCPolarity_High;
  TIM_OC3Init(TIM4, &TIM_OCInitStructure);

  TIM_OC3PreloadConfig(TIM4, TIM_OCPreload_Enable);

  // Konfiguracja kanalu 4
  TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1;
  TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
  TIM_OCInitStructure.TIM_Pulse = 14400ul;        //wypelnienie = 60%
  TIM_OCInitStructure.TIM_OCPolarity=TIM_OCPolarity_High;
  TIM_OC4Init(TIM4, &TIM_OCInitStructure);

  TIM_OC4PreloadConfig(TIM4, TIM_OCPreload_Enable);

  TIM_ARRPreloadConfig(TIM4, ENABLE);
  TIM_Cmd(TIM4, ENABLE);
}