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STMF100RB Encoder Interface

Question asked by Sean Mutlu on Jul 10, 2017

Hello,

I have set up an encoder interface using SPL stm32f10x_tim.h which blinks an LED every time the motor makes a revolution. I am wondering how I would go about getting direction data from a similar setup. 

 

#include "stm32f10x_rcc.h"
#include "stm32f10x_gpio.h"
#include "stm32f10x_tim.h"
#include "misc.h"

/* Private function prototypes -----------------------------------------------*/
static void TIM_Config(void);
void TIM3_IRQHandler (void);
/* Private functions ---------------------------------------------------------*/

/**
* @brief Main program.
* @param None
* @retval None
*/
int main(void)
{

/* TIM Configuration */
TIM_Config();

/* Infinite loop */
while (1)
{
int status = TIM_GetCounter(TIM3);
printf ("status = %d\r\n",status);
}
}

/**
* @brief Configure the TIM pins and the TIM IRQ Handler.
* @param None
* @retval None
*/
static void TIM_Config(void)
{
TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
NVIC_InitTypeDef NVIC_InitStructure;
GPIO_InitTypeDef GPIO_InitStructure;

/* TIM3 clock enable */
RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM3, ENABLE);

/* GPIOA clock enable */
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA|RCC_APB2Periph_GPIOC, ENABLE);

/* TIM1 channel 2 pin (PE.11) configuration */
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_6 | GPIO_Pin_7;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_Init(GPIOA, &GPIO_InitStructure);
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_9;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_PP;
GPIO_Init(GPIOC, &GPIO_InitStructure);

/* Time base configuration */
TIM_TimeBaseStructure.TIM_Prescaler = 0;
TIM_TimeBaseStructure.TIM_ClockDivision = 0;
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
// 48 counts per revolution of the motor shaft & gear ratio 34:1
TIM_TimeBaseStructure.TIM_Period = 1632;
// Initialize TIM3
TIM_TimeBaseInit(TIM3, &TIM_TimeBaseStructure);

/* Set TIM3 to Encoder mode */
TIM_EncoderInterfaceConfig(TIM3, TIM_EncoderMode_TI12, TIM_ICPolarity_Rising, TIM_ICPolarity_Rising);

/* TIM Interrupts enable */
TIM_ITConfig(TIM3, TIM_IT_Update, ENABLE);

/* TIM3 enable counter */
TIM_Cmd(TIM3, ENABLE);

/* Enable the TIM3 global Interrupt */
NVIC_InitStructure.NVIC_IRQChannel = TIM3_IRQn;
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStructure);
}

/*blink LED every revolution */
void TIM3_IRQHandler(void)
{
GPIO_WriteBit(GPIOC,GPIO_Pin_9,Bit_SET);
for (int i = 0; i <100; i++);
GPIO_WriteBit(GPIOC,GPIO_Pin_9,Bit_RESET);
TIM_ClearITPendingBit(TIM3,TIM_IT_Update);

}

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