Posted on November 16, 2015 at 02:01
Please don't delete threads, it damages the integrity of the forum.
From: clive1
Posted: Sunday, November 15, 2015 10:59 PM
Subject: Fixed.
Looks like hours of fun, not sure I'm up for digging through register issues with you.
Your IRQ Handler will need to clear the interrupt, with a TIM1->SR = mask otherwise it will never leave the interrupt state.
From: bush.john
Posted: Sunday, November 15, 2015 9:35 PM
Subject: Stmf407 pwm input capture problem
Hello all, first post on this forum, somewhat of a total newbie, as im sure will become clear on reading my code :).
I'm currently attempting to learn my way around the stm32f407 discovery board. At the moment I'm trying to figure out the PWM capture.
In the code below I have tried to put together a very simple program, to capture some information about pulse width of an incoming signal (using the steps defined in the reference manual) and trigger an interrupt when a sample is received, which dumps any count data to output. Of course, the code runs, but no data timing data is received, and I don't have much of an idea why at this point, though I continue to work at it. I would very muchappreciate any advice offered!
cheers.
#include ''stm32f4xx.h''
#include ''stdio.h''
#include ''usart.c''
#define TIM1_EN 0x01
#define PORTC_CLOCK_EN 2
#define PIN5 5
/*
Goal of project is to sample the high pulse width of a square wave input,
the sample will then be ouputted via UART for confirmation
*/
int placeholder;
void TIM1_CC_IRQHandler(void)
{
placeholder = TIM1->CCR2;
}
int main(void)
{
/*
Setup PORTC PIN5 to capture the pulse width of incomming signal using TIM1 PWM input capture.
On capture, interrupt is triggered and displays contents of TIM1_CCR2 as output via UART
*/
RCC->AHB1ENR |=(1<<
PORTC_CLOCK_EN
); //Enable PORTC clock
RCC->APB2ENR |=(TIM1_EN); //Enable TIM1 clock
GPIOC->AFR[0] |=(1<<
20
); //Assign PORTC Pin5 to TIM1
TIM1->CR1 |=0x01; //Enable count on TIM1
TIM1->CCMR1 |=(0x01); //Set CC1S bits to 01
TIM1->CCER &=~(0x0A); //Set CC1P and CC1NP bits to 0
TIM1->CCMR1 |=(1<<
9
); //Set CC2S bits to 10
TIM1->CCER |=(0x0A0); //Set CC2P and CC2NP bits to 1
TIM1->SMCR |=(0x54); //Set SMS bits to 100 & TS bits to 101
TIM1->CCER |=(0x011); //Enable captures
TIM1->DIER |=(1<<
1
); //Enable capture compare interrupt 1
NVIC->ISER[0] |=(1<<27); //Enable interrupt for TIM1_CC
config_UART2(); //Enable USART output
placeholder =0;
while(1)
{
printf(''value recieved %d
'', placeholder);
}
}
