C source code

  • Posted on: 31 May 2004
  • By: lucas


/*-------------------------------------------------------------------
*
* Product/Project : TestClock
* Program language: PICC C
* Author : Dick Goossens
*
* %name: clock.c %
* %created_by: nly00524 %
* %derived_by: nly00524 %
* %date_created: 21 augustus 2003%
* %date_modified: %
* %version: 231 %
*
* Copyright (C) PHILIPS Centre For Industrial Technology (CFT) 2002
* Mass Products & Technologies
* Sensors & Measurement
* Eindhoven - The Netherlands
*
* All right are reserved. Reproduction in whole or in part is
* prohibited without the written consent of the copyright owner
*-------------------------------------------------------------------
* Description:
* ============
*-------------------------------------------------------------------
* History :
* ============
* watch out with timing errors while displaying
*
*/

/*-------------------------------------------------------------------
* Global includes
*-------------------------------------------------------------------
*/

#include <16f84A.h>

#use DELAY(clock=16000000)

#ID 0x4567
#use FAST_IO(a)
#use FAST_IO(b)

#BYTE TMR0 = 0x01
#BIT T0IF = 0x0B.2 // timer 0 interrupt flag
#BIT T0IE = 0x0B.5 // timer 0 interrupt flag enable
#BIT ADJ = 0x05.0 // PIN_A0
#BIT A0 = 0x05.0 // PIN_A0
#BIT A1 = 0x05.0 // PIN_A1
#BIT A2 = 0x05.0 // PIN_A2
#BIT H24 = 0x05.3 // PIN_A3
#BIT A4 = 0x05.4 // PIN_A4
#BIT B6 = 0x06.6 // PIN_B6
#BIT B7 = 0x06.7 // PIN_B7
#BYTE OPTION_REG = 0x81

INT1 H24N;
INT Hour, HourD, Min, Sec;
INT IncVis;
INT PostScaler, SlowSet;

/*--------------------------------------------------------------------
*/

void init()
{
OPTION_REG=0x87;
set_tris_a(0x18); // Set bits A0, A1, A2 as output, bits A3, A4 as input
set_tris_b(0x00); // Set port b as output
T0IF =0; // Clear timer flag
T0IE =1; // Enable timer interrupt flag
PostScaler =0; // Extra division to slow down clock
IncVis =0; // Increase visibility
Hour =12;
HourD =0; // Hours that show up on display
Min =0;
Sec =0;
}

/*--------------------------------------------------------------------
*/

void H12_To_H24()
{
if (Hour>12 & !H24) // 12H (!H24) of 24H (H24) display
HourD=Hour-12;
else
HourD=Hour;
}

/*--------------------------------------------------------------------
*/

void display()
{
H24N=!H24;

if (!A4) // During "set time" no seconds needed and A0 is in use as input
{
OUTPUT_A(0); //Prevent timing problem
OUTPUT_B(Sec+0x80*H24+0x40*H24N);
OUTPUT_A(1); // select Column 1 : seconds
}
IncVis=0;
while(IncVis<5) // Increase visibility
++IncVis;
OUTPUT_A(0); // Prevent timing problem
OUTPUT_B(Min+0x80*H24+0x40*H24N);
OUTPUT_A(2); // Select Column 2 : minutes
IncVis=0;
while(IncVis<5) // increase visibility
++IncVis;
OUTPUT_A(0); // Prevent timing problem
OUTPUT_B(HourD+0x80*H24+0x40*H24N);
OUTPUT_A(4); // Select Column 3 : hours
}

/*--------------------------------------------------------------------
*/

void set()
{
Sec=0;
OPTION_REG=0x8F; // Enable Prescaler
while (A4)
{
set_tris_a(0x19); // Set bits A1, A2 as output, bits A0, A3, A4 as input

if (ADJ & !H24) // Increment minutes
++Min;
if (Min>60)
Min=0;
if (ADJ & H24) // Increment hours
++Hour;
if (Hour>24)
Hour=0;
H12_To_H24(); // Adjust hours to display

SlowSet=0; // Decrease adjusting speed
while (SlowSet<254)
{
++SlowSet;
While (!T0IF) // Wait loop
{
display();
};
T0IF = 0; // Reset Interrupt flag TMR0
TMR0 = 0; // Load Timer value
}
}
set_tris_a(0x18); // Set bits A0, A1, A2 as output, bits A3, A4 as input
OPTION_REG=0x87;
}

/*--------------------------------------------------------------------
*/

void time()
{

++Sec;

if ( sec > 60 )
{
Sec=0;
++Min;
if ( Min > 60 )
{
Min=0;
++Hour;
if ( Hour>24 )
{
Hour=0;
}; //Hour
}; //Min
}; //Sec
H12_To_H24();
}

/*---------------------------------------------------------------------
*/

void main( void )
{

init(); // Initialising

while(true)
{
if (T0IF) // Interrupt flag TMR0
{
T0IF=0; // Reset Interrupt flag TMR0
TMR0 = 190; // Load Timer value

if ( PostScaler > 15 ) // Prescaler + timer too fast. Divide by 15.
{
time(); // Adjust time
PostScaler=0;
}
else
++PostScaler;

} //end if (T0IF)

Display();

if (A4) // "set time" mode
set();

} // end while
}