stm32 counter up/down and reset on change direction

Question

how to add in this code reset on change direction? counter is tested with signal for stepper motor and working well, counting is up and down but limit is 32767 after -32766 -32765 ..

for reset on change direction i think to add this lines:

TIM_SlaveConfigTypeDef SlaveModeselect
TIM_MasterConfigTypeDef MasterConfig

SlaveModeselect.SlaveMode = ....
SlaveModeselect.InputTrigger = TIM_TS_TI1FP1 

MasterConfig.MasterSlaveMode = TIM_MASTERSLAVEMODE_......
MasterConfig.MasterOutputTrigger = .....

HAL_TIM_SlaveConfigSynchronization(&timer, &SlaveModeselect)
HAL_TIMEx_MasterConfigSynchronization(&timer, &MasterConfig)

Current code:

#include "mbed.h"
#include "stm32f4xx.h"
#include "stm32f4xx_hal_tim_ex.h"

TIM_HandleTypeDef timer;
TIM_Encoder_InitTypeDef encoder;

//direction to PA_9 -- step pulse to PA_8

int main(){
     GPIO_InitTypeDef GPIO_InitStruct;
        __TIM1_CLK_ENABLE();
        __GPIOA_CLK_ENABLE();
        GPIO_InitStruct.Pin = GPIO_PIN_8 | GPIO_PIN_9;
        GPIO_InitStruct.Mode = GPIO_MODE_AF_PP;
        GPIO_InitStruct.Pull = GPIO_PULLDOWN;
        GPIO_InitStruct.Speed = GPIO_SPEED_HIGH;
        GPIO_InitStruct.Alternate = GPIO_AF1_TIM1;
        HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);

    timer.Instance = TIM1;
    timer.Init.Period = 0xffff;
    timer.Init.Prescaler = 1;
    timer.Init.ClockDivision = TIM_CLOCKDIVISION_DIV1;
    timer.Init.CounterMode = TIM_COUNTERMODE_UP;

    encoder.EncoderMode = TIM_ENCODERMODE_TI1; 
    encoder.IC1Filter = 0x0f;
    encoder.IC1Polarity = TIM_INPUTCHANNELPOLARITY_RISING; 
    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_INDIRECTTI;

    HAL_TIM_Encoder_Init(&timer, &encoder);
    HAL_TIM_Encoder_Start(&timer,TIM_CHANNEL_1);   


    TIM1->EGR = 1;           // Generate an update event
    TIM1->CR1 = 1;           // Enable the counter


 while (1) {
        int16_t count1;
        count1=TIM1->CNT; 

        printf("%d\r\n", count1);
        wait(1.0);

 };
}

How does this code count down? To my understanding you only count up, i.e. TIM1->CNT only increases. So then is my understanding correct that after reaching 32767 you want to go to 0 instead of -32766? — jayant, Oct 17 '15 at 08:18

score 1 · Answer 1 · answered Oct 16 '15 at 22:00

1

use uint16_t count1 instead of int16_t to have your counter count up to 65535 then reset to 0 when there is an overflow.

answered Oct 16 '15 at 22:00

jayant

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this is correct but i need reset counter every direction change interrupt not is good solution because step/direction signal is very fast >200 kHz – paolo della vedova Oct 17 '15 at 01:53
i make new program and with same problem! – paolo della vedova Oct 18 '15 at 12:45
I'm not sure what you changed in your new program. Would you be able to update your question to reflect your changes and what you expect the results to be? – jayant Oct 18 '15 at 17:57

stm32 counter up/down and reset on change direction

1 Answers1