SPI is triggering PWM

[cpc]

Hi,

I am using STM32l072CZYx. I am generating the PWM using timer 3 channel 2. But PWM is getting trigger by SPI, PWM is resetting for some time. When I disabled the SPI, I am getting exact PWM.

What will be the reason?

What can be done to avoid such thing?

[cpc]

IS there any update?

void MX_TIM3_Init(void)
{
	__HAL_RCC_TIM3_CLK_ENABLE();
 
	 TIM_ClockConfigTypeDef sClockSourceConfig = {0};
 
	 htim3.Instance = TIM3;
	 htim3.Init.Prescaler = 320;
	 htim3.Init.CounterMode = TIM_COUNTERMODE_UP;
	 htim3.Init.Period = 100;
	 htim3.Init.ClockDivision = TIM_CLOCKDIVISION_DIV1;
	 htim3.Init.AutoReloadPreload = TIM_AUTORELOAD_PRELOAD_DISABLE;
	 HAL_TIMEx_RemapConfig(&htim3,TIM3_TI2_GPIOB5_AF4);
	 if (HAL_TIM_Base_Init(&htim3) != HAL_OK)
	 {
	 Error_Handler();
	 }
	 sClockSourceConfig.ClockSource = TIM_CLOCKSOURCE_INTERNAL;
	 if (HAL_TIM_ConfigClockSource(&htim3, &sClockSourceConfig) != HAL_OK)
	 {
	 Error_Handler();
	 }
	 if (HAL_TIM_PWM_Init(&htim3) != HAL_OK)
	 {
	 Error_Handler();
	 }
 
	 sConfigOC.OCMode = TIM_OCMODE_PWM1;
	 sConfigOC.Pulse = 50;
	 sConfigOC.OCPolarity = TIM_OCPOLARITY_HIGH;
	 sConfigOC.OCFastMode = TIM_OCFAST_ENABLE;
 
	 if (HAL_TIM_PWM_ConfigChannel(&htim3, &sConfigOC, TIM_CHANNEL_2) != HAL_OK)
	 {
	 Error_Handler();
	 }
}

this is timer initialization.

Any external event is affecting the PWM.

I am using LoRa as well.

what is missing in this?

[waclawek.jan]

Shorts between SPI and TIM pins?

Unstable power resetting MCU?

JW

[cpc]

No there is no short between timer and SPI pins. I have also tried using another timer on another pin but same issue.

Is my timer configuration correct?

Am I missing something?

[waclawek.jan]

I don't use Cube, but as long as you set a timer to generate PWM and then don't touch its registers, and unless it's in one-pulse mode, it should tick regularly to infinity.

JW