Electrical – STM32F103 – CubeMX – Timer and Interrupt

I have a program which sets the TIMER1 on the STM32F103 as Output Compare no Output.

In the main.c I have a simple variable, which I set to 1, and in the interrupt handler of TIM1 I have set it up so that variable is 2. In main, I also send the value of the said variable every one second.

All I get on UART is "1111", so the interrupt is never called. Why is that?

main.c:

uint16_t testPixel = 1;
uint8_t myChar[5];
[...]
HAL_TIM_OC_MspInit(&htim1);
[...]
 while (1)
  {
    itoa(testPixel, myChar, 10);
    HAL_UART_Transmit(&huart1,myChar,sizeof(myChar),10);
    HAL_Delay(1000);
  }

TIM1 set-up generated by CubeMX

static void MX_TIM1_Init(void)
{

  TIM_MasterConfigTypeDef sMasterConfig;
  TIM_OC_InitTypeDef sConfigOC;
  TIM_BreakDeadTimeConfigTypeDef sBreakDeadTimeConfig;

  htim1.Instance = TIM1;
  htim1.Init.Prescaler = 0;
  htim1.Init.CounterMode = TIM_COUNTERMODE_UP;
  htim1.Init.Period = 80-1;
  htim1.Init.ClockDivision = TIM_CLOCKDIVISION_DIV1;
  htim1.Init.RepetitionCounter = 0;
  if (HAL_TIM_OC_Init(&htim1) != HAL_OK)
  {
    Error_Handler();
  }

  sMasterConfig.MasterOutputTrigger = TIM_TRGO_RESET;
  sMasterConfig.MasterSlaveMode = TIM_MASTERSLAVEMODE_DISABLE;
  if (HAL_TIMEx_MasterConfigSynchronization(&htim1, &sMasterConfig) != HAL_OK)
  {
    Error_Handler();
  }

  sConfigOC.OCMode = TIM_OCMODE_TIMING;
  sConfigOC.Pulse = 10;
  sConfigOC.OCPolarity = TIM_OCPOLARITY_HIGH;
  sConfigOC.OCNPolarity = TIM_OCNPOLARITY_HIGH;
  sConfigOC.OCFastMode = TIM_OCFAST_DISABLE;
  sConfigOC.OCIdleState = TIM_OCIDLESTATE_RESET;
  sConfigOC.OCNIdleState = TIM_OCNIDLESTATE_RESET;
  if (HAL_TIM_OC_ConfigChannel(&htim1, &sConfigOC, TIM_CHANNEL_1) != HAL_OK)
  {
    Error_Handler();
  }

  sBreakDeadTimeConfig.OffStateRunMode = TIM_OSSR_DISABLE;
  sBreakDeadTimeConfig.OffStateIDLEMode = TIM_OSSI_DISABLE;
  sBreakDeadTimeConfig.LockLevel = TIM_LOCKLEVEL_OFF;
  sBreakDeadTimeConfig.DeadTime = 0;
  sBreakDeadTimeConfig.BreakState = TIM_BREAK_DISABLE;
  sBreakDeadTimeConfig.BreakPolarity = TIM_BREAKPOLARITY_HIGH;
  sBreakDeadTimeConfig.AutomaticOutput = TIM_AUTOMATICOUTPUT_DISABLE;
  if (HAL_TIMEx_ConfigBreakDeadTime(&htim1, &sBreakDeadTimeConfig) != HAL_OK)
  {
    Error_Handler();
  }

}

stm32f1xx_it.c:

extern testPixel;
[...]
void TIM1_UP_IRQHandler(void)
{
  testPixel = 2;
  HAL_TIM_IRQHandler(&htim1);

}

Thank you!