/********************************************************************
 * Filename: 555CalcPC.c
 * 
 * This program calculates the frequency, high time, low time, and 
 * duty cycle for an astable oscillator on a 555 timer chip when
 * given the capacitance and resistance values.
 * 
 * It also calculates the high time for a mono-stable "One Shot".
 * 
 * 
 ********************************************************************/

#include <stdio.h>

#define clrscr() printf("\e[1;1H\e[2J") // Clear screen.

int onpin = 0;
int offpin = 1;
int button = 2;

long mult = 1000000; // Multiplier for capacitance.

/********************************************************************
 * capmult() function - Determine multiplier for capacitor value.
 ********************************************************************/
void capmult()
{
  int choice = 0;

  while(choice < 1 || choice > 3) // Choice must be between 1 and 4.
  {
    clrscr();  // Clear screen.
    printf("\n                            Calculator for 555 Timer\n\n");
    printf("\n                      Determine multiplier for capacitance\n\n");
    printf("                 The formula needs the capacitance to be in Farads.\n");
    printf("                      How do you want to enter the capacitance?\n\n\n");
    printf("                             1 - In nano Farads (nF)\n\n");
    printf("                             2 - In micro Farads (uF)\n\n");
    printf("                             3 - In Farads (F)\n\n");
    printf("\n\n\n\n                               Enter Selection: ");
    scanf("%d", &choice); // Get selection. (choice)

    switch(choice)
    {
      case 1:
        mult = 1000000000;    // Multiplier for nano Farads.
        break;
      case 2:
        mult = 1000000;       // Multiplier for micro Farads.
        break;
      case 3:
        mult = 1;             // Multiplier for Farads.
        break;
    }
  }
}

/********************************************************************
 * astable() function - The code for an astable oscillator.
 ********************************************************************/
void astable()
{

  float r1 = 0;
  float r2 = 0;
  float c1 = 0;

  while(r1 == 0)
  {
    clrscr();  // Clear screen.
    printf("\n                            Calculator for 555 Timer\n");
    printf("                            in an Astable Oscillator\n\n"); 
    printf("\n             Enter R1: ");
    scanf("%f",&r1);
  }

  while(r2 == 0)
  {
    clrscr();  // Clear screen.
    printf("\n                            Calculator for 555 Timer\n");
    printf("                            in an Astable Oscillator\n\n"); 
    printf("\n                                R1 = %7.0f Ohms\n",r1);    
    printf("\n             Enter R2: ");
    scanf("%f",&r2);
  }

  while(c1 ==0)
  {
    clrscr();  // Clear screen.
    printf("\n                            Calculator for 555 Timer\n");
    printf("                            in an Astable Oscillator\n\n"); 
    printf("\n                                R1 = %7.0f Ohms\n",r1);    
    printf("\n                                R2 = %7.0f Ohms\n",r2);    
    if(mult==1) printf("\n       Enter C1 in F: ");
    else if(mult==1000000) printf("\n             Enter C1 in uF: ");
    else if(mult==1000000000) printf("\n             Enter C1 in nF: ");
    scanf("%f",&c1);
  }

  clrscr();  // Clear screen.
  printf("\n                            Calculator for 555 Timer\n");
  printf("\n                            in an Astable Oscillator\n\n"); 
  printf("\n                                R1 = %7.0f Ohms\n",r1);    
  printf("\n                                R2 = %7.0f Ohms\n",r2);    
  if(mult==1) printf("\n                                C1 = %7.3f F\n", c1);
  else if(mult==1000000) printf("\n                                C1 = %7.3f uF\n", c1);
  else if(mult==1000000000) printf("\n                                C1 = %7.3f nF\n", c1);

  printf("                    ----------------------------------------\n");

  c1/=mult;                                   // Peform calculations
  float freq = 1.44 / ((r1 + r2 + r2) * c1);
  float hi = 0.693 * (r1 + r2) * c1;
  float lo = 0.693 * r2 * c1;
  float duty = (hi / (hi + lo)) * 100;

  printf("\n                             Frequency = %7.5f\n",freq); // Display results
  printf("\n                             Time high = %7.5f\n",hi);
  printf("\n                              Time low = %7.5f\n",lo);
  printf("\n                            Duty Cycle = %3.1f Percent\n",duty);

  sleep(20);
}


/********************************************************************
 * mono() function - The code for a mono-stable "One Shot".
 ********************************************************************/
void mono()
{
  float r1 = 0;
  float c1 = 0;

  while(r1 == 0)
  {
    clrscr();  // Clear screen.
    printf("\n                            Calculator for 555 Timer\n");
    printf("                        in Mono-Stable (One shot) mode\n\n");                
    printf("\n             Enter R1: ");
    scanf("%f",&r1);
  }

  while(c1 == 0)
  {
    clrscr();  // Clear screen.
    printf("\n                            Calculator for 555 Timer\n");
    printf("                        in Mono-Stable (One shot) mode\n\n");                
    printf("\n                                R1 = %7.0f Ohms\n",r1);    
    if(mult==1) printf("\n      Enter C1 in F: ");
    else if(mult==1000000) printf("\n             Enter C1 in uF: ");
    else if(mult==1000000000) printf("\n             Enter C1 in nF: ");
    scanf("%f",&c1);
  }

  clrscr();  // Clear screen.
  printf("\n                            Calculator for 555 Timer\n");
  printf("                        in Mono-Stable (One shot) mode\n\n");                
  printf("\n                                R1 = %7.0f Ohms\n",r1);    
  if(mult==1) printf("\n                                C1 = %7.3f F\n", c1);
  else if(mult==1000000) printf("\n                                C1 = %7.3f uF\n", c1);
  else if(mult==1000000000) printf("\n                                C1 = %7.3f nF\n", c1);

  printf("                    ----------------------------------------\n");

  c1/=mult;
  float hi = 1.1 * r1 * c1;
  printf("\n                             Time high = %7.5f\n",hi);
  
  sleep(20);
}

/********************************************************************
 * main() function
 ********************************************************************/
int main()
{
  int choice;

  while(choice != 4) // Display main menu.
  {
    clrscr();  // Clear screen.
    printf("\n                            Calculator for 555 Timer\n\n");
    printf("\n\n\n\n\n                        1 - Astable Oscillator\n");
    printf("\n                        2 - Mono-stable\n");
    printf("\n                        3 - Change multiplier for C1 ");
    if(mult==1) printf("(F)\n");
    else if(mult==1000000) printf("(uF)\n");
    else if(mult==1000000000) printf("(nF)\n");
    printf("\n                        4 - EXIT\n");
    printf("\n\n\n\n\n\n                            Enter Selection: ");
    scanf("%d", &choice); // Get selection. (choice)
    clrscr(); // Clear screen.

    switch(choice)
    {
      case 1:
        astable(); // Run code for astable oscillator.
        break;
      case 2:
        mono();    // Run code for mono-stable "One Shot".
        break;
      case 3:
        capmult(); // Get multiplier for capacitance.
        break;
      case 4:
        clrscr();  // Clear screen and exit.
        break;
    }
  }
  return 0;
}