STM32F4 input output PWM program

[louis23]

Posted on August 14, 2014 at 23:58

Hi

I'm programming this code. It should read a PWM input then ouputs 4 different PWM after calculation based on the input. I've successfully programmed 2 different code: one for the input and one for the output. They worked fine. But when I try to combine them, the program goes into infinite loop or it gives 0 as PWM input reading. Does this code have some kind of conflict between the input and output configuration ?/* Includes */&sharpinclude <stdio.h>&sharpinclude ''stm32f4xx.h''&sharpinclude ''stm32f4_discovery.h''/* Private typedef *//* Private macro *//* Private variables */TIM_TimeBaseInitTypeDef  TIM_TimeBaseStructure;GPIO_InitTypeDef  GPIO_InitStructure;USART_InitTypeDef USART_InitStructure;TIM_OCInitTypeDef  TIM_OCInitStructure;TIM_ICInitTypeDef  TIM_ICInitStructure;uint16_t CCR1_Val = 333;uint16_t CCR2_Val = 249;uint16_t CCR3_Val = 166;uint16_t CCR4_Val = 83;uint16_t PrescalerValue = 0;/* Private function prototypes */void TIM_Config(void);void PWM_Config(int period);void PWM_SetDC(uint16_t channel,uint16_t dutycycle);/* Private functions */int main(void){ TIM_Config(); LED_Config(); PWM_Config(800); while(1) { uint32_t freq = TIM4->CCR2; uint32_t duty = TIM4->CCR1; uint32_t ratio = duty/freq; printf(''freq : %u duty : %u\n'', (unsigned int)freq, (unsigned int)duty); PWM_SetDC(1,ratio*0.25); //TIM3 PC0 PWM_SetDC(2,ratio*0.5); //TIM3 PC1 PWM_SetDC(3,ratio*0.75); //TIM3 PC2 PWM_SetDC(4,ratio*0.99); //TIM3 PC3 }}void TIM_Config(void){ GPIO_InitTypeDef GPIO_InitStructure; NVIC_InitTypeDef NVIC_InitStructure; // OUTPUT CONFIGURATION /* TIM3 clock enable */ RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM3, ENABLE); /* GPIOC clock enable */ RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOC, ENABLE); // OUPUT TIM3 CONFIGURATION /* GPIO Configuration: TIM3 CH1 (PC0) and TIM3 CH2 (PC1) (PC2) (PC3) */ GPIO_InitStructure.GPIO_Pin = GPIO_Pin_6 | GPIO_Pin_7 | GPIO_Pin_8 | GPIO_Pin_9; GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF; GPIO_InitStructure.GPIO_Speed = GPIO_Speed_100MHz; GPIO_InitStructure.GPIO_OType = GPIO_OType_PP; GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP ; GPIO_Init(GPIOC, &GPIO_InitStructure); /* Connect TIM3 pins to AF2 */ GPIO_PinAFConfig(GPIOC, GPIO_PinSource6, GPIO_AF_TIM3); GPIO_PinAFConfig(GPIOC, GPIO_PinSource7, GPIO_AF_TIM3); GPIO_PinAFConfig(GPIOC, GPIO_PinSource8, GPIO_AF_TIM3); GPIO_PinAFConfig(GPIOC, GPIO_PinSource9, GPIO_AF_TIM3); // INPUT CONFIGURATION /* TIM4 clock enable */ RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM4, ENABLE); /* GPIOB clock enable */ RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOB, ENABLE); /* TIM4 chennel2 configuration : PB.07 */ GPIO_InitStructure.GPIO_Pin   = GPIO_Pin_7; GPIO_InitStructure.GPIO_Mode  = GPIO_Mode_AF; GPIO_InitStructure.GPIO_Speed = GPIO_Speed_100MHz; GPIO_InitStructure.GPIO_OType = GPIO_OType_PP; GPIO_InitStructure.GPIO_PuPd  = GPIO_PuPd_UP ; GPIO_Init(GPIOB, &GPIO_InitStructure); /* Connect TIM pin to AF2 */ GPIO_PinAFConfig(GPIOB, GPIO_PinSource7, GPIO_AF_TIM4); /* Enable the TIM4 global Interrupt */ NVIC_InitStructure.NVIC_IRQChannel = TIM4_IRQn; NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0; NVIC_InitStructure.NVIC_IRQChannelSubPriority = 1; NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE; NVIC_Init(&NVIC_InitStructure);}void PWM_Config(int period){ // OUPUT CONFIGURATION -> TIM3 uint16_t PrescalerValue = 0; /* Compute the prescaler value */ PrescalerValue = (uint16_t) ((SystemCoreClock/2)/28000000)-1; /* Time base configuration */ TIM_TimeBaseStructure.TIM_Period = period; TIM_TimeBaseStructure.TIM_Prescaler = PrescalerValue; TIM_TimeBaseStructure.TIM_ClockDivision = 0; TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up; TIM_TimeBaseInit(TIM3, &TIM_TimeBaseStructure); /* PWM1 Mode configuration: Channel 1 */ TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1; TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable; TIM_OCInitStructure.TIM_Pulse = CCR1_Val; TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High; TIM_OC1Init(TIM3, &TIM_OCInitStructure); TIM_OC1PreloadConfig(TIM3, TIM_OCPreload_Enable); /*PWM1 mode configuration : Channel 2 */ TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable; TIM_OCInitStructure.TIM_Pulse = CCR2_Val; TIM_OC2Init(TIM3, &TIM_OCInitStructure); TIM_OC2PreloadConfig(TIM3, TIM_OCPreload_Enable); /* PWM1 Mode configuration: Channel3 */ TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable; TIM_OCInitStructure.TIM_Pulse = CCR3_Val; TIM_OC3Init(TIM3, &TIM_OCInitStructure); TIM_OC3PreloadConfig(TIM3,TIM_OCPreload_Enable); /* PWM1 Mode configuration : Channel4*/ TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable; TIM_OCInitStructure.TIM_Pulse = CCR4_Val; TIM_OC4Init(TIM3, &TIM_OCInitStructure); TIM_OC4PreloadConfig(TIM3,TIM_OCPreload_Enable); TIM_ARRPreloadConfig(TIM3,ENABLE); /* TIM3 ENABLE COUNTER */ TIM_Cmd(TIM3, ENABLE); // INPUT CONFIGURATION TIM_ICInitStructure.TIM_Channel = TIM_Channel_2; TIM_ICInitStructure.TIM_ICPolarity = TIM_ICPolarity_Rising; TIM_ICInitStructure.TIM_ICSelection = TIM_ICSelection_DirectTI; TIM_ICInitStructure.TIM_ICPrescaler = TIM_ICPSC_DIV1; TIM_ICInitStructure.TIM_ICFilter = 0x0; TIM_PWMIConfig(TIM4, &TIM_ICInitStructure); /* Select the TIM4 Input Trigger: TI2FP2 */ TIM_SelectInputTrigger(TIM4, TIM_TS_TI2FP2); /* Select the slave Mode: Reset Mode */ TIM_SelectSlaveMode(TIM4, TIM_SlaveMode_Reset); TIM_SelectMasterSlaveMode(TIM4, TIM_MasterSlaveMode_Enable); /* TIM enable counter */ TIM_Cmd(TIM4, ENABLE); /* Enable the CC2 Interrupt Request */ TIM_ITConfig(TIM4, TIM_IT_CC2, ENABLE);}void PWM_SetDC(uint16_t channel, uint16_t dutycycle){ switch(channel) { case 1: TIM3->CCR1 = dutycycle; break; case 2: TIM3->CCR2 = dutycycle; break; case 3: TIM3->CCR3 = dutycycle; break; case 4: TIM3->CCR4 = dutycycle; break; default: break; }}Thank you. LAL.  #stm32

[Tesla DeLorean]

Posted on August 15, 2014 at 01:18

Explain the significance of 28 MHz and 35 KHz. Have you picked a suitable processor frequency to achieve 28 MHz?

Explain your understanding of integer and floating point numbers, math using them and casting. What is your interrupt code doing?