Posted on January 21, 2018 at 21:31
1
https://stackoverflow.com/questions/48361193/stm32-hal-nucleo-f446re-quadrature-encoder
i have a problem with the quadrature encoder mode on tim3.
1) tim3 counts on every rising edge on the first signal. the CNT register counts up and i read the value with 1hz and then i set the register to 0.
All looks good but...
When i look on the
oscilloscope
the frequency is half as big as the value from theCNT register output (1hz).
if i devide the CNT value by two the result is correct.
Why?
2) tim3 counts on both edges on the first signal. the CNT register output (1hz) is completely wrong.
my config is:
GPIO_InitTypeDef sInitEncoderPin1;
sInitEncoderPin1.Pin = pin1Encoder.pin; // A GPIO_PIN_6
sInitEncoderPin1.Mode = GPIO_MODE_AF_PP;
sInitEncoderPin1.Pull = GPIO_PULLUP;
sInitEncoderPin1.Speed = GPIO_SPEED_HIGH;
sInitEncoderPin1.Alternate = altFunctionEncoder; // GPIO_AF2_TIM3
GPIO_InitTypeDef sInitEncoderPin2;
sInitEncoderPin2.Pin = pin2Encoder.pin; // A GPIO_PIN_7
sInitEncoderPin2.Mode = GPIO_MODE_AF_PP;
sInitEncoderPin2.Pull = GPIO_PULLUP;
sInitEncoderPin2.Speed = GPIO_SPEED_HIGH;
sInitEncoderPin2.Alternate = altFunctionEncoder; // GPIO_AF2_TIM3
HAL_GPIO_Init(GPIOA, &sInitEncoderPin1);
HAL_GPIO_Init(GPIOA, &sInitEncoderPin2);
encoderTimer.Init.Period = 0xffff;
encoderTimer.Init.Prescaler = 0;
encoderTimer.Init.CounterMode = TIM_COUNTERMODE_UP;
encoderTimer.Init.ClockDivision = TIM_CLOCKDIVISION_DIV1;
encoderTimer.Init.RepetitionCounter = 0;
HAL_NVIC_SetPriorityGrouping(NVIC_PRIORITYGROUP_4);
HAL_NVIC_SetPriority(SysTick_IRQn, 0, 1);
encoder.EncoderMode = TIM_ENCODERMODE_TI1;
encoder.IC1Filter = 0x0f;
encoder.IC1Polarity = TIM_INPUTCHANNELPOLARITY_RISING; // TIM_INPUTCHANNELPOLARITY_BOTHEDGE
encoder.IC1Prescaler = TIM_ICPSC_DIV1;
encoder.IC1Selection = TIM_ICSELECTION_DIRECTTI;
encoder.IC2Filter = 0x0f;
encoder.IC2Polarity = TIM_INPUTCHANNELPOLARITY_RISING;
encoder.IC2Prescaler = TIM_ICPSC_DIV1;
encoder.IC2Selection = TIM_ICSELECTION_DIRECTTI;
HAL_TIM_Encoder_Init(&encoderTimer, &encoder);
HAL_TIM_Encoder_Start_IT(&encoderTimer, TIM_CHANNEL_ALL);
Posted on January 22, 2018 at 16:05
using one input, your 1s sample should be 2
x the
scope freq
using two inputs, your 1s sample should be 4 x the scope freq
