STM32F4 einfache PWM

/* Includes */

#include "stm32f4xx.h"

/* Private macro */

/* Private variables */

/* Private function prototypes */

/* Private functions */

void delay()

{

  volatile uint32_t delayCount = 262143;

  while(delayCount > 0)

    delayCount--;

}

void initPWM_LED(void)

{

  TIM_OCInitTypeDef  TIM_OCInitStructure;

  GPIO_InitTypeDef  GPIO_InitStructureTimerPin;

  TIM_TimeBaseInitTypeDef    TIM_TimeBaseStructure;

  //timer and port clock enable

  RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM4, ENABLE);

  RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOD, ENABLE);

  //general port settings

  GPIO_InitStructureTimerPin.GPIO_Mode = GPIO_Mode_AF;

  GPIO_InitStructureTimerPin.GPIO_Speed = GPIO_Speed_100MHz;

  GPIO_InitStructureTimerPin.GPIO_OType = GPIO_OType_PP;

  GPIO_InitStructureTimerPin.GPIO_PuPd = GPIO_PuPd_UP ;

  //set pin 12 to output

  GPIO_InitStructureTimerPin.GPIO_Pin = GPIO_Pin_12;

  GPIO_Init(GPIOD, &GPIO_InitStructureTimerPin);

  //set pin 13 to output

  GPIO_InitStructureTimerPin.GPIO_Pin = GPIO_Pin_13;

  GPIO_Init(GPIOD, &GPIO_InitStructureTimerPin);

  //set pin 14 to output

  GPIO_InitStructureTimerPin.GPIO_Pin = GPIO_Pin_14;

  GPIO_Init(GPIOD, &GPIO_InitStructureTimerPin);

  //set pin 15 to output

  GPIO_InitStructureTimerPin.GPIO_Pin = GPIO_Pin_15;

  GPIO_Init(GPIOD, &GPIO_InitStructureTimerPin);

  //connect TIM4 CH1..5 to PD12..15

  GPIO_PinAFConfig(GPIOD, GPIO_PinSource12, GPIO_AF_TIM4);

  GPIO_PinAFConfig(GPIOD, GPIO_PinSource13, GPIO_AF_TIM4);

  GPIO_PinAFConfig(GPIOD, GPIO_PinSource14, GPIO_AF_TIM4);

  GPIO_PinAFConfig(GPIOD, GPIO_PinSource15, GPIO_AF_TIM4);

  //timer frequency 1kHz

  uint32_t timer_clk=1000000;

  uint32_t timer_out_clk=1000;

  //timer base configuration

  TIM_TimeBaseStructure.TIM_Prescaler = (uint16_t) ((SystemCoreClock/timer_clk)-1);

  TIM_TimeBaseStructure.TIM_Period = (timer_clk/timer_out_clk);

  TIM_TimeBaseStructure.TIM_ClockDivision = 0;

  TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;

  //timer init

  TIM_TimeBaseInit(TIM4, &TIM_TimeBaseStructure);

  //common PWM config

  TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1;

  TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High;

  //special PWM config CH1

  TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;

  TIM_OCInitStructure.TIM_Pulse = (timer_clk/timer_out_clk)/1;

  TIM_OC1Init(TIM4, &TIM_OCInitStructure);

  TIM_OC1PreloadConfig(TIM4, TIM_OCPreload_Enable);

  //special PWM config CH2

  TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;

  TIM_OCInitStructure.TIM_Pulse = (timer_clk/timer_out_clk)/1;

  TIM_OC2Init(TIM4, &TIM_OCInitStructure);

  TIM_OC2PreloadConfig(TIM4, TIM_OCPreload_Enable);

  //special PWM config CH3

  TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;

  TIM_OCInitStructure.TIM_Pulse = (timer_clk/timer_out_clk)/1;

  TIM_OC3Init(TIM4, &TIM_OCInitStructure);

  TIM_OC3PreloadConfig(TIM4, TIM_OCPreload_Enable);

  //special PWM config CH4

  TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;

  TIM_OCInitStructure.TIM_Pulse = (timer_clk/timer_out_clk)/1;

  TIM_OC4Init(TIM4, &TIM_OCInitStructure);

  TIM_OC4PreloadConfig(TIM4, TIM_OCPreload_Enable);

  // preload timer config

  TIM_ARRPreloadConfig(TIM4, ENABLE);

  // enable timer / counter

  TIM_Cmd(TIM4, ENABLE);

}

int main(void)

{

  initPWM_LED();

  TIM_OCInitTypeDef TIM_OCInitStructure;

  int i;

  //while(!GPIO_ReadInputDataBit(GPIOA,GPIO_Pin_0))

  //{;}

  while(1)

  {

    for(i=0;i<1000;i++)

    {

          TIM_Cmd(TIM4, DISABLE);

          TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1;

          TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;

          TIM_OCInitStructure.TIM_Pulse = i;

          TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High;

          TIM_OC4Init(TIM4, &TIM_OCInitStructure);

          TIM_OC4PreloadConfig(TIM4, TIM_OCPreload_Enable);

          TIM_ARRPreloadConfig(TIM4, ENABLE);

          delay();

    }

  }

}