Quadrature encoder on STM32F429 discovery?

vasilevskialeksandar · ‎2014-10-15

Posted on October 15, 2014 at 09:26

Hi,

I have working code on STM32F407 discovery board and would like to port it to discovery board based on STM32F429.

If I set GPIO_Mode_IN on STM32F429 I can see nice shaped signals from encoder on input pins PA1 and PA5. When I set GPIO_Mode_AF pins seems to be driven low from STM32F429 side.

AF is set to TIM2 with:

GPIO_PinAFConfig(GPIOA,GPIO_Pin_5,GPIO_AF_TIM2);

GPIO_PinAFConfig(GPIOA,GPIO_Pin_1,GPIO_AF_TIM2);

Code for timer setting is same for both STM32F407 and STM32F429:

TIM_TimeBaseStructure.TIM_Prescaler = 0x00;

TIM_TimeBaseStructure.TIM_Period = 65536; //max resolution

TIM_TimeBaseStructure.TIM_ClockDivision = TIM_CKD_DIV4;//divide by clock by one

TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;// count up

TIM_TimeBaseInit(TIM2, &TIM_TimeBaseStructure);

TIM_EncoderInterfaceConfig(TIM2, TIM_EncoderMode_TI12, TIM_ICPolarity_Falling, TIM_ICPolarity_Rising);

TIM_ICStructInit(&TIM_ICInitStructure);

TIM_ICInitStructure.TIM_ICFilter = 0;//ICx_FILTER;

TIM_ICInitStructure.TIM_Channel = TIM_Channel_2;

TIM_ICInit(TIM2, &TIM_ICInitStructure);

TIM2->CNT = 0;

TIM_Cmd(TIM2, ENABLE);//enable encoder

Any ideas what can be wrong or differences between 32F407 and 32F429 that can trigger this problem?

Regards,

Aleksandar

#quadrature-encoder-stm32f429

Amel NASRI · ‎2014-10-15

Posted on October 15, 2014 at 10:31

Hi Aleksander,

There are 2 axes for checks:

1- Hardware side: review differences between both boards that may impact your application.

2- Software side: if you are enabling alternate functions on pins PA1 & PA5 after enabling TIM2 clock please try to do the inverse & check again. I am interested to know results.

-Mayla-

To give better visibility on the answered topics, please click on Accept as Solution on the reply which solved your issue or answered your question.

Tesla DeLorean · ‎2014-10-15

Posted on October 15, 2014 at 12:29

GPIO_PinAFConfig(GPIOA,GPIO_PinSource5,GPIO_AF_TIM2);

GPIO_PinAFConfig(GPIOA,GPIO_PinSource1,GPIO_AF_TIM2);

Tips, Buy me a coffee, or three.. PayPal Venmo
Up vote any posts that you find helpful, it shows what's working..

vasilevskialeksandar · ‎2014-10-15

Posted on October 15, 2014 at 12:58

Thanks!

I made mistake during porting. After all both macros are really similar.

BR,

Aleksandar