Sorry ,After Toggling pin i am not finding any difference after/begore disabling TIM3->EGR for below.
Toggle a GPIO output pin when entering the TIM interrupt and observe on oscilloscope. You'll probably be surprised.
The timeStamp1 value is getting updated after the Disabling Event Generation Register
> TIM3->EGR = 1<<1;
#include<NEW.h>
#include<stdio.h>
#include<stdarg.h>
void Ultra_setting();
void delay();
void Tim3_Capture();
void Uart1_config();
void delay1();
void Gpio_Init();
void uart_printf(const char *fmt, ...);
uint32_t timeStamp1 = 0,timeStamp2=0,width=0,Distance=0;
unsigned int flag=0;
void TIM3_IRQHandler()
{
flag++;
GPIOC->ODR =~(1<<8);/*Toggling PC8 pin */
if (flag==1)
{
timeStamp1=TIM3->CCR1;
TIM3->CCER|=1<<1;/*Change to Falling Edge */
}
else
{
timeStamp2=TIM3->CCR1;
TIM3->CNT = 0;
if(timeStamp2>timeStamp1)
{
width= timeStamp2-timeStamp1;
// uart_printf("The distance is %d %d %d %d\n", Distance, timeStamp1,timeStamp2,width);
}
else if(timeStamp2<timeStamp1)
{
width= (0xffff - timeStamp1) + timeStamp2;
}
Distance =width * 0.34/2;
flag=0;
TIM3->CCER =1;//*Change to Rising Edge */
WRITE(NVIC_ISER0 ,(0<<29));/*Disabling TIM3 Interrupt */
TIM3->CR1=0;/*Disable Counter */
uart_printf("The distance is %d %d %d %d\n", Distance, timeStamp1,timeStamp2,width);
}
}
int main()
{
//GPIO A configuration
TIM3->CNT-0;
SystemInit();
Ultra_setting();
Gpio_Init();
Uart1_config();
// while (1)
GPIOA->ODR =1<<8;/* Turning ON PA8pin */
delay();/* 10 microseconds ON*/
GPIOA->ODR =0<<8;/* Turning ON PA8 pin */
Tim3_Capture();
while(1);
}
char buf[512];
void uart_printf(const char *fmt, ...)
{
int ret;
va_list args;
va_start(args, fmt);
ret = vsnprintf(buf, 512, fmt, args);
va_end(args);
if (ret > 0)
{
for (int i =0; i < ret; i++)
{
USART1->SR = 0;
USART1->DR = buf[i];
while(!(USART1->SR & (1<<6)) );
}
}
}
void delay1()
{
RCC->APB1ENR |=1<<0; /* TIM2 clock enabled*/
TIM2->ARR=10000;
TIM2->PSC=1999;
TIM2->CR1 |=1;
while((!TIM2->SR & 1<<0));
TIM2->SR=0;
}
void Gpio_Init()
{
RCC->AHB1ENR |=1; /* Enabling clock for GPIOA port*/
RCC->AHB1ENR |=4; /* Enabling clock for GPIOC port*/
GPIOA->MODER |=2<<12;/*Alternative function in PA6 pORT*/
GPIOA->AFR[0]|=2<<24; /* Alternate function low register is AF1 is TIM3_CH1 */
GPIOC->MODER |=1<<16;/* Enabling general purpose output in PC8 Pin */
}
void Uart1_config()
{
RCC->APB2ENR |=USART1_CLK;
RCC->AHB1ENR |=1;
GPIOA->MODER |=2<<18;/* Enabling Mode of PA9 */
GPIOA->MODER |=2<<20;/*Enabling Mode of PA9 */
GPIOA->OSPEEDR |=3<<18;/* Enabling High speed of PA9*/
GPIOA->OSPEEDR |=3<<20;/* Enabling High speed of PA10*/
GPIOA->AFR[1] |=7<<4;/*Enabling AFR7 of PA9 */
GPIOA->AFR[1] |=7<<8;/*Enabling AFR8 of PA10 */
USART1->CR1 |=USART1_EN;
USART1->BRR =((3<<0) | (0x68<<4)); /*9600 Baud Rate*/
// USART1->CR1 |=USART1_PE;
// USART1->CR1 |=USART1_ODD;
USART1->CR1 |=USART1_RE;
USART1->CR1 |=USART1_TE;
}
void Tim3_Capture()
{
//input capture mode
RCC->APB1ENR |= 2; //ENABLE TIMER 3
TIM3->PSC = 16; //divide by 16
//TIM3->CCMR1 |= (0b01<<0)|(0b0100<<4);
TIM3->CCMR1 |= (0b01<<0)|(0b0100<<4);
// TIM3->CCMR1|=TIM2_CCIS;
TIM3->CCER = 1; //enable CH1 input capture
WRITE(NVIC_ISER0 ,(1<<29));
TIM3->DIER =1<<1;
// TIM3->EGR=1<<1;
TIM3->CR1=1;
TIM3->CNT=0;
}
void Ultra_setting()
{
RCC->AHB1ENR |=1; /* Enabling clock for GPIOA port*/
GPIOA->MODER |=1<<16;/*General Purpose output function in PA9 Port*/
GPIOA->OSPEEDR|=1<<16;/*Medium speed */
}
void delay()
{
RCC->APB1ENR |=1<<0; /* TIM2 clock enabled*/
TIM2->CNT=0;
TIM2->ARR=98;
TIM2->PSC=1;
TIM2->CR1 |=1;
while((!TIM2->SR & 1<<0));
TIM2->SR=0;
}
