sseg.c

/**************************************************************************
 *
 * FILE NAME:            sseg.c
 * FILE DESCRIPTION:    SSEG driver
 * FILE CREATION DATE:    9-01-2010
 *
 *==========================================================================
 * This document contains confidential information which is protected by copyright 
 * and is proprietary. No part of this document may be used, copied, disclosed, 
 * or conveyed to another party without prior written consent of its owner
 ***************************************************************************
 *
 * Modification history:
 * --------------------
 * 01a,9jan10 erd    written
 *
 ***************************************************************************/

#include "sysdef.h"
#include "sys.h"
#include "sseg_prv.h"

// ==========================================================================
// init seven segment

void sseg_init()
{
    // 1:16 and 1:16 scalars
    T2CON = 0b01111011;
    
    // set period (every 600uS)
    PR2 = 24;
    
    // enable interrupts
    TMR2IE = 1; 

    // init decpt state
    sseg_decptState = FALSE;
}    
// ==========================================================================
// start displaying

void sseg_startDisplay(void)
{
    // start timer2
    TMR2ON = 1;
}
// ==========================================================================
// set the number on the display

void sseg_setDisplay(uint_16 numberToDisplay)
{
    // init values
    uint_8 thousands, hundreds, tens, units;
    thousands = hundreds = tens = units = 0;

    // split number
    while (numberToDisplay >= 1000){thousands++; numberToDisplay -= 1000;}
    while (numberToDisplay >= 100){hundreds++; numberToDisplay -= 100;}
    while (numberToDisplay >= 10){tens++; numberToDisplay -= 10;}
    units = numberToDisplay;

    // set to display array
    sseg_digitValues[3] = sseg_digitLedMap[units];
    sseg_digitValues[2] = sseg_digitLedMap[tens];
    sseg_digitValues[1] = sseg_digitLedMap[hundreds];
    sseg_digitValues[0] = sseg_digitLedMap[thousands];

    // set decpt
    sseg_setDecPtStates(sseg_decptState);
}    
// ==========================================================================
// seven segment ISR

void sseg_isr(void)
{
    uint_8 previousSelectReg;
    
    // get previous
    previousSelectReg = (IO_SSEG_SELECT & 0xF0);

    // update new select
    previousSelectReg |= (1 << sseg_currentDigit);

    // select current digit
    IO_SSEG_SELECT = previousSelectReg;

    // load current digit
    IO_SSEG_DISPLAY = sseg_digitValues[sseg_currentDigit];

    // next digit
    sseg_currentDigit++;

    // and wrap
    if (sseg_currentDigit >= 4) sseg_currentDigit = 0;
}
// ==========================================================================
// set dots (currently support only on or off)

void sseg_setDecPtStates(BOOL state)
{
    // save state
    sseg_decptState = state;
    
    // set decpt
    if (state)
    {
        // clear appropriate bit
        sseg_digitValues[0] &= ~SSEG_DECPT;
        sseg_digitValues[1] &= ~SSEG_DECPT;
        sseg_digitValues[2] &= ~SSEG_DECPT;
        sseg_digitValues[3] &= ~SSEG_DECPT;
    }
    // clear decpt
    else
    {
        // set appropriate bit
        sseg_digitValues[0] |= SSEG_DECPT;
        sseg_digitValues[1] |= SSEG_DECPT;
        sseg_digitValues[2] |= SSEG_DECPT;
        sseg_digitValues[3] |= SSEG_DECPT;
    }
}
// ==========================================================================
// toggle dots (currently support only on or off)

void sseg_toggleDecPtStates(void)
{
    // toggle values
    sseg_decptState = !sseg_decptState;

    // set
    sseg_setDecPtStates(sseg_decptState);
}
// ==========================================================================