#include "stm32f4xx.h"
#include "stm32f4xx_rcc.c"
#include "stm32f4xx_gpio.c"
#include "stm32f4xx_tim.c"
#include "stm32f4xx_dac.c"

#include "LCD2x16.c"
#include "math.h"
#include "dd.h"

int Table[4096], ptrTable, K = 655, dK = 0;
char InPat = 0;
int PortE, f_VCO;

// DAC init function
void DACinit (void)     {
DAC_InitTypeDef         DAC_InitStructure;
GPIO_InitTypeDef        GPIO_InitStructure;
  RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOA, ENABLE);
  GPIO_InitStructure.GPIO_Pin   = GPIO_Pin_4 | GPIO_Pin_5;
  GPIO_InitStructure.GPIO_Mode  = GPIO_Mode_AN;
  GPIO_InitStructure.GPIO_PuPd  = GPIO_PuPd_NOPULL;  
  GPIO_Init(GPIOA, &GPIO_InitStructure);  
  
  RCC_APB1PeriphClockCmd(RCC_APB1Periph_DAC, ENABLE);
  DAC_InitStructure.DAC_OutputBuffer                 = DAC_OutputBuffer_Enable;
  DAC_InitStructure.DAC_Trigger                      = DAC_Trigger_None;
  DAC_InitStructure.DAC_WaveGeneration               = DAC_WaveGeneration_None;
  DAC_Init(DAC_Channel_1, &DAC_InitStructure); 
  DAC_Init(DAC_Channel_2, &DAC_InitStructure);
  
  DAC_Cmd(DAC_Channel_1, ENABLE);   
  DAC_Cmd(DAC_Channel_2, ENABLE);
}

// Timer 5 init function - time base
void TIM5init_TimeBase_ReloadIRQ (int interval)  {
TIM_TimeBaseInitTypeDef TIM_TimeBaseInitStructure;
  RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM5,  ENABLE);
  TIM_TimeBaseInitStructure.TIM_ClockDivision = TIM_CKD_DIV1;
  TIM_TimeBaseInitStructure.TIM_CounterMode = TIM_CounterMode_Up;
  TIM_TimeBaseInitStructure.TIM_Period = interval;
  TIM_TimeBaseInitStructure.TIM_Prescaler = 0;
  TIM_TimeBaseInitStructure.TIM_RepetitionCounter = 0;
  TIM_TimeBaseInit(TIM5, &TIM_TimeBaseInitStructure);

  NVIC_EnableIRQ(TIM5_IRQn);                 // Enable IRQ for TIM5 in NVIC 
  TIM_ITConfig(TIM5, TIM_IT_Update, ENABLE); // Enable IRQ on update for Timer5

  TIM_Cmd(TIM5, ENABLE);
}   

// initialize port E, Gpio_Pin_8 to GPIO_Pin_11 as outputs
void GPIOEinit_8to11 (void)   {
GPIO_InitTypeDef        GPIO_InitStructure;
  RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOE, ENABLE);
  GPIO_InitStructure.GPIO_Pin   = GPIO_Pin_8  | GPIO_Pin_9  | GPIO_Pin_10 | GPIO_Pin_11;
  GPIO_InitStructure.GPIO_Mode  = GPIO_Mode_OUT;
  GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_100MHz;
  GPIO_InitStructure.GPIO_PuPd  = GPIO_PuPd_NOPULL;
  GPIO_Init(GPIOE, &GPIO_InitStructure); 
}

int main ()  {
  
  // Table init for analog output
  for (ptrTable = 0; ptrTable <= 4095; ptrTable++)
    Table[ptrTable] = (int)(1850.0 * sin((float)ptrTable / 2048.0 * 3.141592653));
  
  LCD_init(); LCD_string("Fin=", 0x01); LCD_string("Hz", 13);
  GPIOEinit_8to11();
  DACinit();
  TIM5init_TimeBase_ReloadIRQ(840);    // 840 == 10us == 100kHz

  // endless loop - display frequency
  while (1) {
    LCD_uInt16((int)(K * 100000 / 65536),0x07,1);     // display frequency
    for (int i = 0; i < 5000000; i++) {};            // waste time
  };
}

// IRQ function for Timer5
void TIM5_IRQHandler(void)      // PLL takes approx 600 ns of CPU time!
{
  GPIOE->BSRRL =  BIT_8;        // 
  TIM_ClearITPendingBit(TIM5, TIM_IT_Update); // clear interrupt flag
  PortE = GPIOE->IDR & BIT_15;  // read input signal
  f_VCO = ptrTable   & 0x8000;  // this is locally generated signal
  InPat = (InPat << 2) & 0x0c;  // construct pattern for phase detector
  if (PortE) InPat += 2;        //
  if (f_VCO) InPat += 1;        //
  if (PortE == f_VCO)       dK =  0;    // if equal signals (frequencies)
  else { if (InPat == 0x02) dK =  1;    // if frequency too high
         if (InPat == 0x0d) dK =  1;    // 
         if (InPat == 0x01) dK = -1;    // if frequency too low
         if (InPat == 0x0e) dK = -1;    //
  };
  K += dK;                              // correct time interval
  if (K > 0x8000) K = 0x8000;           // but not too much
  if (K < 0x0080) K = 0x0080;           //
  ptrTable = (ptrTable + K + (dK << 8)) & 0xffff;    // update pointer to table
  GPIOE->ODR = (GPIOE->ODR & ~BIT_10) | (f_VCO >> 5);// digital out - f_VCO
  DAC->DHR12R1 = (Table[ptrTable >> 4]) + 2048;      // analog signal -> DAC
  DAC->DHR12R2 = K >> 2;                             // frequency -> DAC
  GPIOE->BSRRH = BIT_8;        // 
}