#include "stm32f4xx.h"
#include "stm32f4xx_rcc.c"
#include "stm32f4xx_gpio.c"
#include "stm32f4xx_tim.c"
#include "LCD2x16.c"
#include "dd.h"

// Timer 3 init function - use as PWM
void TIM3init_PWM_CenterAligned (void)  {
TIM_TimeBaseInitTypeDef TIM_TimeBaseInitStructure;
TIM_OCInitTypeDef       TIM_OCInitStructure;
  //int PrescalerValue = (uint16_t) ((SystemCoreClock /2) / 21000000) - 1;

  RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM3, ENABLE);
  TIM_TimeBaseInitStructure.TIM_CounterMode = TIM_CounterMode_CenterAligned3;
  TIM_TimeBaseInitStructure.TIM_Period = 1024;
  TIM_TimeBaseInitStructure.TIM_Prescaler = 3; //PrescalerValue;
  TIM_TimeBaseInit(TIM3, &TIM_TimeBaseInitStructure);

  /* PWM1 Mode configuration: Channel1 */
  TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1;
  TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
  TIM_OCInitStructure.TIM_Pulse = 409;
  TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High;
  TIM_OC1Init(TIM3, &TIM_OCInitStructure);
  TIM_OC1PreloadConfig(TIM3, TIM_OCPreload_Enable);

  /* PWM1 Mode configuration: Channel2 */
  TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
  TIM_OCInitStructure.TIM_Pulse = 614;
  TIM_OC2Init(TIM3, &TIM_OCInitStructure);
  TIM_OC2PreloadConfig(TIM3, TIM_OCPreload_Enable);

  TIM_Cmd(TIM3, ENABLE);
}   

// initialize port C, motor control, Pin_6 to Pin_9 and Pin_11 as outputs
void GPIOCinit_TIM3_PWM (void)   {
GPIO_InitTypeDef        GPIO_InitStructure;
  RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOC, ENABLE);
  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_OType = GPIO_OType_PP;
  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_25MHz;
  GPIO_InitStructure.GPIO_PuPd  = GPIO_PuPd_DOWN;
  GPIO_Init(GPIOC, &GPIO_InitStructure); 

  GPIO_InitStructure.GPIO_Pin   = GPIO_Pin_11;
  GPIO_InitStructure.GPIO_Mode  = GPIO_Mode_OUT;
  GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_25MHz;
  GPIO_InitStructure.GPIO_PuPd  = GPIO_PuPd_DOWN;
  GPIO_Init(GPIOC, &GPIO_InitStructure); 
  GPIOC->BSRRL = BIT_11;
  
  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);
}

// initialize port E (switches), Gpio_Pin_3 to GPIO_Pin_6 as inputs
void SWITCHinit (void)  {
GPIO_InitTypeDef        GPIO_InitStructure;
  RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOE, ENABLE);
  GPIO_InitStructure.GPIO_Pin   = GPIO_Pin_3 | GPIO_Pin_4 | 
                                  GPIO_Pin_5 | GPIO_Pin_6;
  GPIO_InitStructure.GPIO_Mode  = GPIO_Mode_IN;
  GPIO_InitStructure.GPIO_OType = GPIO_OType_PP; 
  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_100MHz;
  GPIO_InitStructure.GPIO_PuPd  = GPIO_PuPd_DOWN;
  GPIO_Init(GPIOE, &GPIO_InitStructure); 
}

int main ()  {
int PWMratio = 512, switches;
  GPIOCinit_TIM3_PWM();
  LCD_init();                           // init LCD
  LCD_string("PWM linear motor", 0x00);    // display title string
  LCD_string("%", 0x48);    // display title string
  SWITCHinit ();
  TIM3init_PWM_CenterAligned();
  
  while (1)     {
    switches = GPIOE->IDR;
    if (switches & S370)  PWMratio++;  // S370
    if (switches & S371)  PWMratio--;  // S371
    if (PWMratio <    1) PWMratio = 1;
    if (PWMratio > 1020) PWMratio = 1020;
    TIM3->CCR1 = PWMratio;
    TIM3->CCR2 = 1024 - PWMratio;
    LCD_sInt3DG((int)((PWMratio-512)/512.0*100),0x44,0x05);    // write to LCD, signed, 16 bits
    for (int i = 0; i < 1000000; i++)   {};
  };
}