Posted on June 19, 2018 at 18:29
I am trying to configure the TIM2 to act as an up/down counter as describe in Encoder mode 1 or 2. I have the circuit set up to connect PB8 to a count signal and PB9 as a direction signal. I have am having an issue where randomly after an NVIC_Reset the count direction is different dispite the value on PB9 being the same. The itnitialization code is below:
void initializeStepDir()
{
TIM_HandleTypeDef timer;
TIM_Encoder_InitTypeDef encoder;
// Enable syscfg clock
RCC->APB2ENR |= (RCC_APB2ENR_SYSCFGEN);
// Reset the TIM2 block
RCC->APB1RSTR |= (RCC_APB1RSTR_TIM2RST);
RCC->APB1RSTR &= ~(RCC_APB1RSTR_TIM2RST);
// Enable the TIM2 block
RCC->APB1ENR |= (RCC_APB1ENR_TIM2EN);
timer.Instance = TIM2;
timer.Init.Period = 0xffffffff;
timer.Init.Prescaler = 1;
timer.Init.ClockDivision = TIM_CLOCKDIVISION_DIV1;
timer.Init.CounterMode = TIM_COUNTERMODE_UP;
constexpr uint32_t FILTER_NUMBER = 3;
encoder.EncoderMode = TIM_ENCODERMODE_TI1;
encoder.IC1Filter = FILTER_NUMBER;
encoder.IC1Polarity = TIM_INPUTCHANNELPOLARITY_RISING; //step signal
encoder.IC1Prescaler = TIM_ICPSC_DIV1;
encoder.IC1Selection = TIM_ICSELECTION_DIRECTTI;
encoder.IC2Filter = FILTER_NUMBER;
encoder.IC2Polarity = TIM_INPUTCHANNELPOLARITY_BOTHEDGE; //check direction
encoder.IC2Prescaler = TIM_ICPSC_DIV1;
encoder.IC2Selection = TIM_ICSELECTION_INDIRECTTI;
HAL_TIM_Encoder_Init(&timer, &encoder);
HAL_TIM_Encoder_Start(&timer, TIM_CHANNEL_ALL);
// NOTE: TI1 -> PB8 TI2 -> PB9
// https://community.st.com/external-link.jspa?url=https%3A%2F%2Fstackoverflow.com%2Fquestions%2F32947972%2Fstm32-how-to-make-pulse-count-up-down-with-timer
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What could cause the system to behave differently given the same inputs? Is this the correct configuration? The stack overflow link in the code suggests that it is for some configuration.
