STM32F4 Timer External Pulse counting

[piotrek700]

Posted on May 18, 2013 at 00:23

Since 4 day I'm trying write code which will be able to count external pulses. I tried to use encoder mode but i supposed that this work only with 2 quadrature encoders. I have only one pulse signal and i have no idea how to do it. Could you help me or show examples how to count external pulses using timer?

#counter #timer #off-topic #pulce

[Tesla DeLorean]

Posted on September 04, 2013 at 16:51

Probably acting in input capture mode, or whatever the default settings are.

/* External input pulse on CH1 */ TIM1->CCR1 = TIM1->CNT; TIM1->CNT++; Like I said, I don't think it plays any functional role related to the external count input routing.

[denis]

Posted on September 05, 2013 at 09:42

Ok clive1 :)

[Tesla DeLorean]

Posted on March 25, 2014 at 00:57

Quick port for F1 series parts

void TIM3_Configuration(void) // STM32F1xx
{
GPIO_InitTypeDef GPIO_InitStructure;
TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
/* GPIOC clock enable */
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOC | RCC_APB2Periph_AFIO, ENABLE);
/* TIM3 clock enable */
RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM3, ENABLE);
/* GPIO Configuration: TIM3 CH1 (PC6) */
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_6;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;
GPIO_Init(GPIOC, &GPIO_InitStructure);
GPIO_PinRemapConfig(GPIO_FullRemap_TIM3, ENABLE); // Get TIM3 to PC6
TIM_TimeBaseStructure.TIM_Period = 65535;
TIM_TimeBaseStructure.TIM_Prescaler = 0;
TIM_TimeBaseStructure.TIM_ClockDivision = 0;
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
TIM_TimeBaseInit(TIM3, &TIM_TimeBaseStructure);
TIM_TIxExternalClockConfig(TIM3, TIM_TIxExternalCLK1Source_TI1, TIM_ICPolarity_Rising, 0);
TIM_Cmd(TIM3, ENABLE);
} // sourcer32@gmail.com

[fireon89]

Posted on August 07, 2014 at 20:55

/* pulse_counter.phr */

#include ''main.h'' int cnt; void TIM3_Configuration(void); void TIM3_Configuration(void) { GPIO_InitTypeDef GPIO_InitStructure; TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure; /* GPIOC clock enable */ RCC_AHBPeriphClockCmd(RCC_AHBPeriph_GPIOC, ENABLE); /* TIM3 clock enable */ RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM3, ENABLE); /* GPIOA Configuration: TIM3 CH1 (PC6) */ GPIO_InitStructure.GPIO_Pin = GPIO_Pin_6; GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF; // Input/Output controlled by peripheral GPIO_InitStructure.GPIO_Speed = GPIO_Speed_2MHz; GPIO_InitStructure.GPIO_OType = GPIO_OType_PP; GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP; // Button to ground expectation GPIO_Init(GPIOC, &GPIO_InitStructure); /* Connect TIM3 pins to AF */ GPIO_PinAFConfig(GPIOC, GPIO_PinSource6, GPIO_AF_0); TIM_TimeBaseStructure.TIM_Period = 65535; TIM_TimeBaseStructure.TIM_Prescaler = 0; TIM_TimeBaseStructure.TIM_ClockDivision = 0; TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up; TIM_TimeBaseInit(TIM3, &TIM_TimeBaseStructure); TIM_TIxExternalClockConfig(TIM3, TIM_TIxExternalCLK1Source_TI2, TIM_ICPolarity_Rising, 0); TIM_Cmd(TIM3, ENABLE); } int main(void) { while(1) { TIM3_Configuration(); cnt=TIM3->CNT ; } } i used this code to count the external pulse , but the counter is not counting . is there any mistakes in the code??

[Tesla DeLorean]

Posted on August 07, 2014 at 21:19

You must copy-n-paste better,

TIM_TIxExternalClockConfig(TIM3, TIM_TIxExternalCLK1Source_TI2, TIM_ICPolarity_Rising, 0); // NOT TI2 And don't keep reconfiguring the timer in the while() loop

[fireon89]

Posted on August 08, 2014 at 06:28

Thanks for the guidance Clive1

I moved the timer config statement out of the while loop and replaced TI2 with TI1 but still the counter is not working I am using STM32f051 eval board 

[fireon89]

Posted on August 08, 2014 at 21:46

Hi clive1 ,

I did try using different timer (TIM1) this one showed some response to the external pulse but it counted randomly. I tried to my best to make it count but didn't workout . can I learn how to make it work from you. thanks

#include ''main.h''
int count=0;
void main()
{ 
// INTI CLOCK FOR TIM AND GPIO
GPIO_InitTypeDef GPIO_InitStructure;
TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
/* GPIOC clock enable */
RCC_AHBPeriphClockCmd(RCC_AHBPeriph_GPIOA, ENABLE);
/* TIM1 clock enable */
RCC_APB2PeriphClockCmd(RCC_APB2Periph_TIM1, ENABLE);
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_9;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_2MHz;
GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_DOWN; 
GPIO_Init(GPIOA, &GPIO_InitStructure);
GPIO_PinAFConfig(GPIOA, GPIO_PinSource9, GPIO_AF_2);
TIM_TimeBaseStructure.TIM_Period = 1000;
TIM_TimeBaseStructure.TIM_Prescaler = 0;
TIM_TimeBaseStructure.TIM_ClockDivision = 0;
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
TIM_TimeBaseInit(TIM3, &TIM_TimeBaseStructure);
TIM_TIxExternalClockConfig(TIM1, TIM_TIxExternalCLK1Source_TI2, TIM_ICPolarity_Rising, 0);
TIM_Cmd(TIM1, ENABLE);
while(1)
{
count = TIM1->CNT;
}
}

[Tesla DeLorean]

Posted on August 09, 2014 at 06:24

As I don't have a board, try this blind modification

#include ''main.h''
int count=0;
void main()
{
// INTI CLOCK FOR TIM AND GPIO
GPIO_InitTypeDef GPIO_InitStructure;
TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
/* GPIOC clock enable */
RCC_AHBPeriphClockCmd(RCC_AHBPeriph_GPIOA, ENABLE);
/* TIM1 clock enable */
RCC_APB2PeriphClockCmd(RCC_APB2Periph_TIM1, ENABLE);
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_9;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_2MHz;
GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_DOWN;
GPIO_Init(GPIOA, &GPIO_InitStructure);
GPIO_PinAFConfig(GPIOA, GPIO_PinSource9, GPIO_AF_2); // TIM1_CH2
TIM_TimeBaseStructure.TIM_Period = 1000 - 1;
TIM_TimeBaseStructure.TIM_Prescaler = 0;
TIM_TimeBaseStructure.TIM_ClockDivision = 0;
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
TIM_TimeBaseStructure.TIM_RepetitionCounter = 0;
TIM_TimeBaseInit(TIM1, &TIM_TimeBaseStructure);
TIM_TIxExternalClockConfig(TIM1, TIM_TIxExternalCLK1Source_TI2, TIM_ICPolarity_Rising, 0);
TIM_CtrlPWMOutputs(TIM1, ENABLE);
TIM_Cmd(TIM1, ENABLE);
while(1)
{
count = TIM1->CNT;
}
}

[fireon89]

Posted on August 09, 2014 at 17:48

Hi Clive ,

I got some example code form the reference manual, and it was working but i was not able to understand these lines.where can I learn to code like this.

GPIOA->MODER = (GPIOA->MODER & ~(GPIO_MODER_MODER9))| (GPIO_MODER_MODER9_1); /* (3) */
//GPIOA->PUPDR = 0x24000000;
GPIOA->PUPDR = 0x1 <<
17
;
GPIOA->AFR[1] |= 0x2 << ((9-8)*4); /* (4) */

[Tesla DeLorean]

Posted on August 09, 2014 at 18:41

If you want to learn register level minutia, then you'll need to absorb all the detail in the Reference Manual, and the bits and functions, and pin level associations. Hours of fun, not a style of programming I would recommend.