Lesson nr.13-7Segment and Push Button

Hardware setup:
Today Lesson is different from the last one, by the presence of two buttons and manually increment .
All 7-segment displays are connected to PORTB (RB0..RB7, segment A to RB0, segment B to RB1, etc.) with refresh via pins RA0..RA3 on PORTA.
If button on RA6 is presed the current number will be incremented by "1" and if button on RA7 is pressed the current number will be decremented by "1". Minimum number is 0000 and maximum number is 9999.



Circuit Diagram:
For those who want to build it on their own breadboard or other platform, here is the electronic scheme built in Eagle Cad, free version:

Software:
Here is the C program written for MikroC PRO for PIC 2010 (version v4.15).

/*
'*******************************************************************************
'  Lesson nr.13:
'          Push Button & 7 Segment Display
'  Done by:
'          Aureliu Raducu Macovei, 2010.
'  Description:
'          This code demonstrates  displaying number on four 7-segment display (common
'          cathode), in multiplex mode. All 7-segment displays are connected to PORTB
'          (RB0..RB7, segment A to RB0, segment B to RB1, etc.) with refresh via pins
'          RA0..RA3 on PORTA. If button on RA6 is presed the current number will be
'          incremented by "1" and if button on RA7 is pressed the current number will
'          be decremented by "1".
'
'  Test configuration:
'    MCU:                        PIC16F628A
'    Test.Board:                 WB-106 Breadboard 2420 dots
'    SW:                         mikroC PRO for PIC
'  Configuration Word
'    Oscillator:                 INTOSC:I/O on RA.6, I/O on RA.7
'    Watchdog Timer:             OFF
'    Power up Timer:             Disabled
'    Master Clear Enable:        Enabled
'    Browun Out Detect:          Enabled
'    Low Voltage Program:        Disabled
'    Data EE Read Protect:       Disabled
'    Code Protect:               OFF
'*******************************************************************************
*/
//***********Header*************/
unsigned short mask(unsigned short num)
{
 switch (num) 
 {
  case 0 : return 0x3F;
  case 1 : return 0x06;
  case 2 : return 0x5B;
  case 3 : return 0x4F;
  case 4 : return 0x66;
  case 5 : return 0x6D;
  case 6 : return 0x7D;
  case 7 : return 0x07;
  case 8 : return 0x7F;
  case 9 : return 0x6F;
  }
}
/*******Endless mask***********/
unsigned short shifter, portb_index;
unsigned int digit, number;
unsigned short portb_array[4];

void interrupt()
{
 PORTA = 0;                           // Turn off all 7seg. displays;
 PORTB = portb_array[portb_index];    // Bring appropriate value to PORTB;
 PORTA = shifter;                     // Turn on appropriate 7seg. display;

 //move shifter to next digit;
 shifter <<= 1;
 if(shifter > 15u)
 shifter = 1;

 //increment portb_index;
 portb_index ++ ;
 if (portb_index > 3u)
 portb_index = 0;                     //turn on 1st, turn off 2nd 7 seg.;
 TMR0 = 0;                            //reset TIMER0 value;
 INTCON = 0x20;                       //clear T0IF, Bit T0IF=0, T0IE=1;
 }

void main()
{
 CMCON |= 7;                          // Set AN pins to Digital I/O;
 OPTION_REG = 0x80;                   // Set timer TMR0;
 digit = 0;
 portb_index = 0;
 shifter = 1;
 TMR0 = 0;
 INTCON = 0xA0;                       // Disable interrupt PEIE,INTE,RBIE,T0IE
 TRISA = 0;
 TRISA6_bit = 1;
 TRISA7_bit = 1;                      // All port A pins are configured as outputs
 PORTA = 0;                           // Turn off displays
 TRISB = 0;                           // All port D pins are configured as outputs
 PORTB = 0;                           // Turn off all display segments
 
 number = 0;                          //initial value;
 
 do {
     if(Button(&PORTA,6,1,0)){
                              Delay_ms(200);
                              digit++ ;
                              number = number +1;
                              PORTB = number;
                              }
     if(Button(&PORTA,7,1,0)){
                              Delay_ms(200);
                              digit = digit -1;
                              number = number -1;
                              PORTB = number;
                              }
     if (number > 9999u)
     number = 0;

     digit = number % 10u;            //extract ones digit;
     portb_array[0] = mask(digit);    //and store it to PORTB array;
     digit = (number / 10u) % 10u;    //extract tens digit;
     portb_array[1] = mask(digit);    //and store it to PORTB array;
     digit = (number / 100u) % 10u;   //extract hundreds digit;
     portb_array[2] = mask(digit);    //and store it to PORTB array;
     digit = number / 1000u;          //extract thousands digit;
     portb_array[3] = mask(digit);    //and store it to PORTB array;
     } while(1);                      //Endless loop;
}                                     //End.