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STM32f4 different timers

fiulala
Associate II

‎2015-10-08 08:35 AM

Posted on October 08, 2015 at 17:35

Hi,

I'm working with stm32f4-disco. I made a code that works well: the micro waits for an external interrupt, and when receives the interrupt it makes pulses of 40kHz with a duration of 1 ms. Now, I wanted to configure another timer so that it makes an output of 100Hz in a pin. In this case I try to configure TIM1 in PA8 but I tried also TIM14 in PA7. The problem is that the pin doesn't make output. Here's the code: 

// Assumptions per system_stm32f4xx.c CPU @ 168 MHz, APB2 @ 84 MHz (/2), APB1 @ 42 MHz (/4)
int modulatingcount=0;
/**************************************************************************/
void RCC_Configuration(void)
{
/* GPIO's clock enable */
RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOA, ENABLE);
/* Enable SYSCFG clock */
RCC_APB2PeriphClockCmd(RCC_APB2Periph_SYSCFG, ENABLE);
/* TIM's clock enable */
RCC_APB2PeriphClockCmd(RCC_APB2Periph_TIM1, ENABLE);
RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM13, ENABLE);
}
/**************************************************************************/
void GPIO_Configuration(void)
{
GPIO_InitTypeDef GPIO_InitStructure;
/* GPIOA Configuration: TIM13 CH1 (PA6) */
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_6;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_100MHz;
GPIO_InitStructure.GPIO_OType = GPIO_OType_OD;
GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL;
GPIO_Init(GPIOA, &GPIO_InitStructure);
/*GPIOA Configuration: TIM1 CH1 (PA8)*/
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_8;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;
GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_Init(GPIOA, &GPIO_InitStructure);
/* Connect TIM1 pins to AF */
GPIO_PinAFConfig(GPIOA, GPIO_PinSource8, GPIO_AF_TIM1);
/* Connect TIM13 pins to AF */
GPIO_PinAFConfig(GPIOA, GPIO_PinSource6, GPIO_AF_TIM13);
/* Configure PA0 pin as input floating (EXTI, arduino)*/
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN;
GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL;
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0;
GPIO_Init(GPIOA, &GPIO_InitStructure);
}
/**************************************************************************/
void NVIC_Configuration(void)
{
NVIC_InitTypeDef NVIC_InitStructure;
/* Enable the TIM13 global Interrupt */
NVIC_InitStructure.NVIC_IRQChannel = TIM8_UP_TIM13_IRQn;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 1;
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStructure);
}
/**************************************************************************/
uint32_t Period;
void TIM13_Configuration(void)
{
TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
TIM_OCInitTypeDef TIM_OCInitStructure;
//Periode en ticks, (168Mhz/2)/40kHz
Period = (SystemCoreClock / 2) / 40000; // 40 KHz, from APB1 clock *2, nominally 84 MHz
/* Time base configuration */
TIM_TimeBaseStructure.TIM_Prescaler = 0;
TIM_TimeBaseStructure.TIM_Period = Period - 1;
TIM_TimeBaseStructure.TIM_ClockDivision = 0;
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
TIM_TimeBaseInit(TIM13, &TIM_TimeBaseStructure);
/* PWM1 Mode configuration: Channel1 */
TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1;
TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
TIM_OCInitStructure.TIM_Pulse = Period / 2; // 50/50 duty
TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High;
TIM_OC1Init(TIM13, &TIM_OCInitStructure);
TIM_OC1PreloadConfig(TIM13, TIM_OCPreload_Enable);
/* TIM Interrupts enable */
TIM_ITConfig(TIM13, TIM_IT_Update, ENABLE);
}
/**************************************************************************/
#define TimerON 40
void TIM8_UP_TIM13_IRQHandler(void) // 40KHz
{
if (TIM_GetITStatus(TIM13, TIM_IT_Update) != RESET) // Validate source
{
TIM_ClearITPendingBit(TIM13, TIM_IT_Update); // Clear source
modulatingcount++;
if (modulatingcount > TimerON){
TIM_Cmd(TIM13, DISABLE);
}
}
}
void TIM1_Configuration(void)
{
TIM_OCInitTypeDef TIM_OCInitStructure;
TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
uint16_t Period;
Period = 1000000 / 100; // 100 Hz for 1MHz prescaled
/* Time base configuration */
TIM_TimeBaseStructure.TIM_Prescaler = (SystemCoreClock / 1000000) - 1;
TIM_TimeBaseStructure.TIM_Period = Period - 1;
TIM_TimeBaseStructure.TIM_ClockDivision = 0;
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
TIM_TimeBaseInit(TIM1, &TIM_TimeBaseStructure);
/* Enable TIM1 Preload register on ARR */
TIM_ARRPreloadConfig(TIM1, ENABLE);
/* TIM PWM1 Mode configuration */
TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1;
TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
TIM_OCInitStructure.TIM_Pulse = Period / 2; // 50%
TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High;
/* Output Compare PWM1 Mode configuration: Channel1 PA.08 */
TIM_OC1Init(TIM1, &TIM_OCInitStructure);
TIM_OC1PreloadConfig(TIM1, TIM_OCPreload_Enable);
/* TIM1 Main Output Enable */
TIM_CtrlPWMOutputs(TIM1, ENABLE);
/* TIM1 enable counter */
TIM_Cmd(TIM1, ENABLE);
}
/**************************************************************************************/
static void EXTILine0_Config(void);
void GPIO_Initialize(void);
GPIO_InitTypeDef GPIO_InitStructure;
NVIC_InitTypeDef NVIC_InitStructure;
static void EXTILine0_Config(void)
{
EXTI_InitTypeDef EXTI_InitStructure;
// Connect EXTI Line0 to PA0 pin
SYSCFG_EXTILineConfig(EXTI_PortSourceGPIOA, EXTI_PinSource0);
// Configure EXTI Line0
EXTI_InitStructure.EXTI_Line = EXTI_Line0;
EXTI_InitStructure.EXTI_Mode = EXTI_Mode_Interrupt;
EXTI_InitStructure.EXTI_Trigger = EXTI_Trigger_Rising;
EXTI_InitStructure.EXTI_LineCmd = ENABLE;
EXTI_Init(&EXTI_InitStructure);
// Enable and set EXTI Line0 Interrupt to the lowest priority
NVIC_InitStructure.NVIC_IRQChannel = EXTI0_IRQn;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0x0F;
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 2;
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStructure);
}
void EXTI0_IRQHandler(void)
{
if(EXTI_GetITStatus(EXTI_Line0) != RESET)
{
//Toggle LED
STM_EVAL_LEDToggle(LED4);
modulatingcount=0;
TIM_Cmd(TIM13, ENABLE);
// Clear the EXTI line 0 pending bit
EXTI_ClearITPendingBit(EXTI_Line0);
}
}
/**************************************************************************************/
int main(void)
{
RCC_Configuration();
NVIC_Configuration();
GPIO_Configuration();
TIM1_Configuration();
TIM13_Configuration();
EXTILine0_Config();
STM_EVAL_LEDInit(LED4);
STM_EVAL_LEDOn(LED4);
while(1){
}
}

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3 REPLIES 3
Tesla DeLorean
Guru

‎2015-10-08 08:46 AM

Posted on October 08, 2015 at 17:46

TIM1 will need more through initialization, the time base has a repetition field, and the channels have enables, and negated outputs.

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Tesla DeLorean
Guru

‎2015-10-08 08:54 AM

Posted on October 08, 2015 at 17:54 

void TIM1_Configuration(void)
{
TIM_OCInitTypeDef TIM_OCInitStructure;
TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
uint16_t Period;
Period = 1000000 / 100; // 100 Hz for 1MHz prescaled
/* Time base configuration */
TIM_TimeBaseStructure.TIM_Prescaler = (SystemCoreClock / 1000000) - 1;
TIM_TimeBaseStructure.TIM_Period = Period - 1;
TIM_TimeBaseStructure.TIM_ClockDivision = 0;
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
TIM_TimeBaseStructure.TIM_RepetitionCounter = 0;
TIM_TimeBaseInit(TIM1, &TIM_TimeBaseStructure);
/* Enable TIM1 Preload register on ARR */
TIM_ARRPreloadConfig(TIM1, ENABLE);
/* TIM PWM1 Mode configuration */
TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1;
TIM_OCInitStructure.TIM_Pulse = Period / 2; // 50%
TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High;
TIM_OCInitStructure.TIM_OCIdleState = TIM_OCIdleState_Reset;
TIM_OCInitStructure.TIM_OutputNState = TIM_OutputNState_Disable;
TIM_OCInitStructure.TIM_OCNPolarity = TIM_OCNPolarity_High;
TIM_OCInitStructure.TIM_OCNIdleState = TIM_OCIdleState_Reset;
/* Output Compare PWM1 Mode configuration: Channel1 PA.08 */
TIM_OC1Init(TIM1, &TIM_OCInitStructure);
TIM_OC1PreloadConfig(TIM1, TIM_OCPreload_Enable);
/* TIM1 Main Output Enable */
TIM_CtrlPWMOutputs(TIM1, ENABLE);
/* TIM1 enable counter */
TIM_Cmd(TIM1, ENABLE);
}

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fiulala
Associate II

‎2015-10-08 09:46 AM

Posted on October 08, 2015 at 18:46 

Totally right. I just tried changing TIM1 for TIM9 with same configuration and it works too. With your code works also. Thank you

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