Changing GPIO pin from PWM to Digital Output at run time

[GunkutA]

Hello, in STM32F10x, I need to use Stop mode. However, before going to stop mode, I need to stop PWM channels and leave them high (in output). How can I stop change some pins (A0 and A6) from timer PWM mode to normal output mode? I tried this method but it did not work:

HAL_TIM_PWM_Stop(&htim2,TIM_CHANNEL_1);
HAL_TIM_PWM_Stop(&htim3,TIM_CHANNEL_1);	
HAL_GPIO_DeInit(GPIOA,GPIO_PIN_0);
HAL_GPIO_DeInit(GPIOA,GPIO_PIN_6);
HAL_GPIO_Init(GPIOA,GPIO_PIN_0);
HAL_GPIO_Init(GPIOA,GPIO_PIN_6);
HAL_GPIO_WritePin(GPIOA, GPIO_PIN_0, GPIO_PIN_RESET);
HAL_GPIO_WritePin(GPIOA, GPIO_PIN_6, GPIO_PIN_RESET);
HAL_GPIO_WritePin(GPIOA,GPIO_PIN_0,1);
HAL_GPIO_WritePin(GPIOA,GPIO_PIN_6,1);

 This way also did not work:

	//Make PWM channels outputs:
	//Reset A port
	GPIOA->CRL |= (1<<9);
	//output mode General purpose output push/pull (PA0)
	GPIOA->CRL &= ~(0b0000<<0);
	GPIOA->CRL |=(0b0010<<0);
	//output mode General purpose output push/pull (PA6)
	GPIOA->CRL &= ~(0b0000<<24);
	GPIOA->CRL |=(0b0010<<24);
	//Set PA0 high
	GPIOA->ODR |= GPIO_ODR_ODR0;
	//Set PA6 high
	GPIOA->ODR |= GPIO_ODR_ODR6;

[TDK]

> HAL_GPIO_DeInit(GPIOA,GPIO_PIN_0);

> HAL_GPIO_DeInit(GPIOA,GPIO_PIN_6);

> HAL_GPIO_Init(GPIOA,GPIO_PIN_0);

> HAL_GPIO_Init(GPIOA,GPIO_PIN_6);

This should have given you error during compiling.

See the following example for how to initialize GPIO pins:

https://github.com/STMicroelectronics/STM32CubeF1/blob/441b2cbdc25aa50437a59c4bffe22b88e78942c9/Projects/STM3210C_EVAL/Examples/GPIO/GPIO_IOToggle/Src/main.c

[GunkutA]

Thank you. But why the second method does not work?

[TDK]

Not going to dig into it. Inspecting the registers should provide your answer. My guess is you're not properly clearing bits. These do nothing: *> GPIOA->CRL &= ~(0b0000<<0);* *> GPIOA->CRL &= ~(0b0000<<24);*

[GunkutA]

Wouldn't this clear the bits?

GPIOA->CRL &= ~(0b0000<<0);

Then how can I clear them?

[GunkutA]

ah yes GPIOA->CRL &= ~(0b0011<<0);

Would work I believe