// Change the following to change the clock frequency
#define CRYSTAL_FREQ    16000000
// Speed units are "1" (nautical knots), "2" (metric kph), or "3" (statute mph)
#define SPEED_UNITS     1

/****************************************************************************
GPS21f.c

WORKING CODE

used with Garmin GPSMAP 172C
used on vessel "Northern Light" Malletts Bay, Vermont, USA


                          +5                    +5  +5
                           |                     |   |
                          20                    15   2
                      ----------             ----------
                     |          |-24-----11-|DB4 A Vdd |
                     |          |-28-----12-|DB5       |
        ADC0 ------2-|          |-26-----13-|DB6       |
        ADC1 ------3-|  18F252  |-27-----14-|DB7     Vo|
        ADC2 ------5-|          |           |    LCD   |
                     |          |-14------6-|EN        |
             XTAL--9-|          |-15------4-|R/S       |
             XTAL-10-|          |-25-FET-16-|K         |
                     |          |           |          |
       BUTTON 1---21-|          |-12------3-|V0        |
       BUTTON 2---22-|          |           |  RW  Vss |
       BUTTON 3---23-|          |            ----------
                     |          |              1   5
      Tach In ----13-|          |              |   |
  ~Seatalk In ----16-|          |             Gnd Gnd
~NMEA-0183 In ----18-|          |
                     |          |-11------- GARMIN/NMEA selector
                      ----------
                        8   19
                        |    |
                       Gnd  Gnd

***************************************************************************/
#case
#include < 18F252.h >
#device *=16 ADC=10                /* allow RAM addresses over 255 */
#include < jonsinc.h >
#fuses HS, NOPROTECT, NOOSCSEN, BROWNOUT, NOWDT, BORV20, PUT, NOSTVREN, NODEBUG, NOLVP, NOWRT, NOWRTD, NOWRTB

#if ( ( CRYSTAL_FREQ < 4000000) || ( CRYSTAL_FREQ > 20000000 ) )
#error "CRYSTAL FREQ" not defined to between 8000000 and 20000000
#endif

// RMC_TIME = 1 per clock megahertz, rounded
#define RMC_TIME        CRYSTAL_FREQ/1000000

// DISPLAY DEFINES ========================
#define LCD_D4          PIN_B3
#define LCD_D5          PIN_B7
#define LCD_D6          PIN_B5
#define LCD_D7          PIN_B6
#define LCD_EN          PIN_C3
#define LCD_RS          PIN_C4
#define RX_IN           PIN_C7
#define LCD_BACKLITE    PIN_B4
#define LINE_1          0x00
#define LINE_2          0x40
#define LINE_3          0x14
#define LINE_4          0x54
#define CLEAR_DISP      0x01
// MISC DEFINES ===========================
#define EOF             0x00
#define COMMA           ','
#define CR              13
#define SPACE           ' '
#define PERIOD          '.'
#define DEGREE          0xdf
#define DOLLAR          '$'
#define NULL            0
#define BUTTON_1        PIN_B0
#define BUTTON_2        PIN_B1
#define BUTTON_3        PIN_B2
#define USB_NMEA_GARMIN PIN_C0
#define NMEA_CONNECTED  0
#define GARMIN_CONNECTED 1
#define GPRMC_CODE      75
#define GPRMB_CODE      74
#define RX_BUFFER_SIZE  70
#define MAX_VOLTS       15
// EEPROM ASSIGNMENTS
#define EEPROM_CONTRAST 0
#define EEPROM_INITIAL  2
#define EEPROM_BACKLIGHT  4
#define EEPROM_SCREENROLL 6
#define EEPROM_USB_PROTOCOL 8
// First-time-write 16-bit eeprom
// partial contrast, first screen, backlight off, screen roll on, NMEA connected
#rom 0xf00000 = { 150, 1, 0, 0, 0 }
// SCREEN DEFINES ====================
#define POSITION_SCREEN 1
#define WAYPOINT_SCREEN 2
#define BATTERY_SCREEN  3
#define TACH_SCREEN     4
#define TANK_SCREEN     5
#define INST_SCREEN     6
#define HIDDEN_RMC      7
#define USB_SCREEN      8
#define WARNING_MSG     0
#define NODATA_MSG      1
#define USB_MSG         2
#define ACTIVITY_SYMBOL 0xFF
#define GPS_BUTTON      0
#define INST_BUTTON     1
#define SYSTEMS_BUTTON  2
#define NUL_BUTTON      0xff
// SCREEN ROLL DEFINES
// screen roll count = display seconds / 0.016
#define SCREEN_ROLL_COUNT   312
// button inactivity count = inactive seconds / 0.016
#define BUTTON_INACTIVITY_COUNT   37500
// TACHOMETER DEFINES ================
#define START_TACH  0
#define RUN_TACH    1
#define DONE_TACH   2
//    Pulley factor is alternator pulley diameter divided by crank pulley diameter, plus a fudge factor
#define ENGINE_DIA      1.000
#define ALT_DIA         0.543
#define PULLEY_FACTOR   ALT_DIA/ENGINE_DIA
//    Obtain alternator poles from manufacturers data sheet (6, 8, 10, etc.)
#define ALTERNATOR_POLES 10
// SEATALK COMMON DEFINES ============
#define NINTH_BIT           7
#define SEATALK_OK          0
#define SEATALK_TIMEOUT     1
#define SEATALK_DATA_ERROR  2
#define SEATALK_RESET_TIME  312
// TANK LEVEL DEFINES ================
#define TANK_MSGNUM         0xFE
#define TANK_ADR            2
#define TANK_LEVEL          3
// INSTRUMENT LEVEL DEFINES ==========
#define INST_ACCUM_TIME     70
#define TEMP_MSGNUM         0x27
#define SPEED_MSGNUM        0x20
#define DEPTH_MSGNUM        0x00
#define HEADING_MSGNUM      0x9c
// DURING GPS CODING ONLY
/* Set the following define to "YES" to display XOR'ed GPS sentence code */
/* such as GPRMC and the display will read out the value of 74. */
#define GET_GPS_CODE    NO

#separate void Display ( void );
#separate void LCD_Init ( void );
#separate void LCD_SetPosition ( unsigned int cX );
#separate void LCD_PutChar ( unsigned int cX );
#separate void LCD_PutCmd ( unsigned int cX );
#separate void LCD_PulseEnable ( void );
#separate void LCD_SetData ( unsigned int cX );
#separate void SkipField ( char cCnt );
#separate char GetField ( void );
#separate void InitRxBuffer ( char cCode );
#separate char GetRxChar ( void );
#separate void DisplayPosition ( void );
#separate void DisplayWaypoint ( void );
#separate void DisplayLatitude ( char cLine );
#separate void DisplayLongitude ( char cLine );
#separate void DisplayHeading ( char cLine );
#separate void DisplaySpeed ( char cLine );
#separate void DisplaySteer ( char cLine, char cX );
#separate void DisplayWaypointName ( char cLine, char cX );
#separate void DisplayDistance ( char cLine, char cX );
#separate void DisplayBearing ( char cLine, char cX );
#separate void GetUtcAndMagVar ( void );
#separate long TrueToMag ( long iH );
#separate long FieldFiveToLong ( void );
#separate void JustifyDecimalPoint ( void );
#separate void DisplayAnalog ( void );
#separate void DisplayScaledVoltage ( long iV, char cScale );
#separate void DisplayArrival ( char cLine );
#separate void DisplayMessage ( char cMsgNum );
#separate void DisplayTemplateLatLon ( void );
#separate void DisplayTemplateWaypoint ( void );
#separate void DisplayTemplateAnalog ( void );
#separate void Delay5mS ( char cCnt );
#separate void DisplayTemplateTach ( void );
#separate void DisplayTemplateTank ( void );
#separate void DisplayTemplateInstruments ( void );
#separate void DisplayTach ( void );
#separate void DisplayTank ( void );
#separate void DisplayInstruments ( void );
#separate char ReceiveSeatalkMsg ( void );
#separate void WriteBlanks ( char cCnt );
#separate void ToggleActivityIndicator ( void );

#use standard_io ( A )
#use standard_io ( B )
#use standard_io ( C )
#use delay ( clock = CRYSTAL_FREQ )
#use rs232 ( baud = 4800, xmit = PIN_C6, rcv = PIN_C7, errors, stream = 1 )    // for GPS interface, hardward USART
#use rs232 ( baud = 4800, rcv = PIN_C5, bits = 9, INVERT, errors, stream = 2 ) // for SeaTalk tank level interface
#priority RDA, RTCC

static char cC [ 10 ];             // local buffer
static char cNmeaDataTimeOut;
static char cRxBuffer [ RX_BUFFER_SIZE ];    // Fifo
static char cRxByteCnt;            // Number of bytes in the recv fifo
static char *cRxBufferWritePtr;    // Pointers for the Rx buffer
static char *cRxBufferReadPtr;
static char cRxIsrState, cRxMsgTypeReceived, cRxMsgTypeDesired;
static char cRxMsgReady, cReceiveFlag;
static long iVar, iLastRange, iTimeOut;
static char cVarDir, cScreenChanged, cAdcDone;
static char cSkip, cButton1Count, cButton2Count, cButton3Count;
static char cScreen, cSavedScreen, cRmcTimer1, cRmcTimer2;
static char cToFrom [ 5 ], cIndicator, cIllumination, cRxErrorFlag;
static char cDone, cContrast, cLastButton;
static char cLastGpsScreen, cLastInstScreen, cLastSystemsScreen;
static char cTachState;
static long iTachCount;
static char cSwitch1State, cSwitch2State, cSwitch3State;
static char cOldSwitch1State, cOldSwitch2State, cOldSwitch3State;
static char cNewSwitch1State, cNewSwitch2State, cNewSwitch3State;
static char cBusTimeout, cSeatalkChar [ 18 ];
static long iSeatalkTimeout0, iSeatalkTimeout1, iSeatalkTimeout2;
static long iSeatalkTimeout3, iSeatalkTimeout4;
static char cSeatalkDisplay;
static char cInstDepthHi, cInstDepthLo, cInstSpeedHi, cInstSpeedLo;
static char cInstHeadingHi, cInstHeadingLo, cInstTempHi, cInstTempLo;
static char cTankLevel0, cTankLevel1, cTankLevel2;
static long iScreenRollCount, iButtonInactivityCount;
static char cScreenRoll;
static char cUsbConnection;

/*******************************************************************/
#int_ad
void AdcInterrupt ( void )
    {
    /* Gets here when ADC is done conversion, sets flag */
    cAdcDone = YES;
    }

#int_timer1
void Timer1Interrupt ( void )
    {
    /* Periodic RMC data timer, gets here every 204mS */
    /* This routine forces RMC to run every 10 minutes to update */
    /* magnetic variation */
    if ( cRmcTimer1-- == 0 )
        {
        cRmcTimer1 = 255;               // 52 seconds @ 10.240MHz
        if ( cRmcTimer2-- == 0 )
            {
            cRmcTimer2 = RMC_TIME;      // triggers every 10 minutes
            cSavedScreen = cScreen;     // save current screen type
            cScreen = HIDDEN_RMC;       // force RMC to run
            }
        }
    }

#int_ccp1
void CCP1Interrupt ( void )
    {
    // for tachometer
    if ( cTachState == RUN_TACH ) // second edge
        {
        iTachCount = CCP_1;       // get capture value
        cTachState = DONE_TACH;   // prevent further processing during this interrupt      }
        }
    if ( cTachState == START_TACH )   // first edge
        {
        set_timer1 ( 0 );     // restart timer on this edge
        cTachState = RUN_TACH;
        }
    }

#int_timer0
void Timer0Interrupt ( void )
    {
    // Timer interrupt gets here every 16.4mS
    // Handles all timeouts and switch debounce.

    // GPS DATA TIMEOUT TIMER
    if ( cNmeaDataTimeOut != 0 )
        {
        cNmeaDataTimeOut--;
        }

    // HUNG LOOP TIMEOUT
    // This timer is preset by the normal operating loop,
    // unless the operating loop stops looping, at which
    // point code finally decrements to zero and resets CPU.
    if ( iTimeOut != 0 )
        {
        iTimeOut--;
        }
    else
        {
        reset_cpu();                // force reset
        }

    // SEATALK TIMEOUTS
    // Gather seatalk data vs. display seatalk data timeout
    if ( cSeatalkDisplay != 0 )
        {
        cSeatalkDisplay--;
        }
    // lack of data timeout
    if ( iSeatalkTimeout0 != 0 )
        {
        iSeatalkTimeout0--;
        }
    if ( iSeatalkTimeout1 != 0 )
        {
        iSeatalkTimeout1--;
        }
    if ( iSeatalkTimeout2 != 0 )
        {
        iSeatalkTimeout2--;
        }
    if ( iSeatalkTimeout3 != 0 )
        {
        iSeatalkTimeout3--;
        }
    if ( iSeatalkTimeout4 != 0 )
        {
        iSeatalkTimeout4--;
        }

    // SCREEN ROLL
    // determine how long since a button was pressed
    if ( iButtonInactivityCount != 0 )
        {
        iButtonInactivityCount--;
        }
    if ( iScreenRollCount != 0 )
        {
        iScreenRollCount--;
        }
    if ( cScreenRoll == YES )
        {
        if ( ( iScreenRollCount == 0 ) && ( iButtonInactivityCount == 0 ) )
            {
            switch ( cScreen )
                {
                case POSITION_SCREEN:
                    {
                    cScreen = WAYPOINT_SCREEN;
                    break;
                    }
                case WAYPOINT_SCREEN:
                    {
                    cScreen = INST_SCREEN;
                    break;
                    }
                case INST_SCREEN:
                    {
                    cScreen = BATTERY_SCREEN;
                    break;
                    }
                case BATTERY_SCREEN:
                    {
                    cScreen = TACH_SCREEN;
                    break;
                    }
                case TACH_SCREEN:
                    {
                    cScreen = TANK_SCREEN;
                    break;
                    }
                case TANK_SCREEN:
                    {
                    cScreen = POSITION_SCREEN;
                    break;
                    }
                }
            cScreenChanged = YES;
            cSkip = YES;
            iScreenRollCount = SCREEN_ROLL_COUNT;
            }
        }

    // SWITCH 1 DEBOUNCE
    if ( input ( BUTTON_1 ) == LOW )  // if button still pressed
        {
        if ( cButton1Count < 255 )   // hold at 255
            {
            cButton1Count++;         // otherwise increment
            }
        }
    else            // if button is unpressed
        {
        if ( cButton1Count > 2 )     // filter out glitches
            {
            //If button press is greater than 4 seconds, cold reset
            if ( cButton1Count == 255 )
                {
                reset_cpu();
                }
            // If button press is 1 second
            if ( ( cButton1Count > 31 ) && ( cButton1Count < 255 ) )
                {
                if ( cScreen != HIDDEN_RMC )       // if not in the middle of getting magnetic variation
                    {
                    // cIllumination ^= ON;
                    output_bit ( LCD_BACKLITE, cIllumination ^= ON );
                    }
                }
            // If button press is less than 0.5 second
            if ( cButton1Count <= 31 )
                {
                iButtonInactivityCount = BUTTON_INACTIVITY_COUNT;
                if ( cScreen != HIDDEN_RMC )       // if not in the middle of getting magnetic variation
                    {
                    if ( cLastButton != GPS_BUTTON )  // if here from another screen
                        {
                        cSwitch1State = cOldSwitch1State;   // use last displayed screen
                        }
                    else
                        {
                        cSwitch1State = cNewSwitch1State;   // otherwise use next screen
                        }
                    switch ( cSwitch1State )
                        {
                        case 0:
                            {
                            cScreen = POSITION_SCREEN;
                            cNewSwitch1State = 1;
                            break;
                            }
                        case 1:
                            {
                            cScreen = WAYPOINT_SCREEN;
                            cNewSwitch1State = 0;
                            break;
                            }
                        }
                    cLastButton = GPS_BUTTON;       // remember which button
                    cOldSwitch1State = cSwitch1State;   // remember which screen
                    cSkip = YES;                // skip out of anything in process
                    cScreenChanged = YES;       // repaint complete screen
                    }
                }
            }
        cButton1Count = 0;       // restart
        }

    // SWITCH 2 DEBOUNCE
    if ( input ( BUTTON_2 ) == LOW )  // if button still pressed
        {
        if ( cButton2Count < 255 )   // hold at 255
            {
            cButton2Count++;         // otherwise increment
            }
        }
    else            // if button is unpressed
        {
        if ( cButton2Count > 2 )     // filter out glitches
            {
            iButtonInactivityCount = BUTTON_INACTIVITY_COUNT;
            if ( cLastButton != INST_BUTTON )  // if here from another screen
                {
                cSwitch2State = cOldSwitch2State;   // use last displayed screen
                }
            else
                {
                cSwitch2State = cNewSwitch2State;   // otherwise use next screen
                }
            switch ( cSwitch2State )
                {
                case 0:
                    {
                    cScreen = INST_SCREEN;
                    cNewSwitch2State = 0;
                    break;
                    }
                }
            cLastButton = INST_BUTTON;       // remember which button
            cOldSwitch2State = cSwitch2State;   // remember which screen
            cSkip = YES;                // skip out of anything in process
            cScreenChanged = YES;       // repaint complete screen
            }
        cButton2Count = 0;       // restart
        }

    // SWITCH 3 DEBOUNCE
    if ( input ( BUTTON_3 ) == LOW )  // if button still pressed
        {
        if ( cButton3Count < 255 )   // hold at 255
            {
            cButton3Count++;         // otherwise increment
            }
        }
    else            // if button is unpressed
        {
        if ( cButton3Count > 2 )     // filter out glitches
            {
            // If button press is 1 second
            if ( ( cButton3Count > 31 ) && ( cButton3Count < 255 ) )
                {
                if ( cScreen != HIDDEN_RMC )       // if not in the middle of getting magnetic variation
                    {
                    // flip USB connection state
                    output_bit ( USB_NMEA_GARMIN, cUsbConnection ^= 1 );
                    cSavedScreen = cScreen;     // save current screen type
                    cScreen = USB_SCREEN;       // force USB screen to show briefly
                    }
                }
            // If button press is less than 0.5 second
            if ( cButton3Count <= 31 )
                {
                iButtonInactivityCount = BUTTON_INACTIVITY_COUNT;
                if ( cLastButton != SYSTEMS_BUTTON )  // if here from another screen
                    {
                    cSwitch3State = cOldSwitch3State;   // use last displayed screen
                    }
                else
                    {
                    cSwitch3State = cNewSwitch3State;   // otherwise use next screen
                    }
                switch ( cSwitch3State )
                    {
                    case 0:
                        {
                        cScreen = BATTERY_SCREEN;
                        cNewSwitch3State = 1;
                        break;
                        }
                    case 1:
                        {
                        cScreen = TACH_SCREEN;
                        cNewSwitch3State = 2;
                        break;
                        }
                    case 2:
                        {
                        cScreen = TANK_SCREEN;
                        cNewSwitch3State = 0;
                        break;
                        }
                    }
                }
            cLastButton = SYSTEMS_BUTTON;       // remember which button
            cOldSwitch3State = cSwitch3State;   // remember which screen
            cSkip = YES;                // skip out of anything in process
            cScreenChanged = YES;       // repaint complete screen
            }
        cButton3Count = 0;       // restart
        }
    }

#int_rda
void SerialInterrupt ( void )
    {
    /*
    Reads incoming data from the USART and puts in in a rolling buffer
    ( but in this application, it should never roll.)
    If the buffer is full, this routine just discards the received byte.
    Not checking the LRC byte at the end of the NMEA-0183 sentence.
    */
    char cChar;

    if ( rs232_errors & 0x04 )  // get framing error bit from Rx status reg
        {
        cRxErrorFlag = ON;
        }
    cChar = fgetc ( 1 );       // get char from UART, clear any errors

    if ( cRxByteCnt == RX_BUFFER_SIZE ) // is recv fifo full ?
        {
        goto done;
        }
    switch ( cRxIsrState )
        {
        case 0:
            {
            if ( cChar == DOLLAR )  // if start of NMEA0183 message
                {
                cRxByteCnt = 0;     // reset byte count
                cReceiveFlag = OFF;     // default to off
                cRxMsgTypeReceived = NULL;  // set hashed value to null
                cRxIsrState++;                 // next state
                }
            break;
            }
        case 1:                           // five type characters to obtain
        case 2:
        case 3:
        case 4:
        case 5:
            {
            cRxMsgTypeReceived ^= cChar;      // hash in msg type
            if ( cRxIsrState++ == 5 )        // if time to check message type
                {
                if ( cRxMsgTypeReceived == cRxMsgTypeDesired )  // if good
                    {
                    cReceiveFlag = YES;            // enable receiving
                    cRxBufferWritePtr = cRxBuffer;    // reset to beginning of buffer
                    }
                else                    // don't want this message
                    {
                    cRxIsrState = 0;    // reset to look for next msg
                    }
                }
            break;
            }
        case 6:
            {
            /* Case 6 skips the comma character following msg type */
            cRxIsrState++;
            break;
            }
        default:                          // remainder of characters
            {
            if ( cReceiveFlag == YES )        // if this message is wanted
                {
                *cRxBufferWritePtr = cChar;     // put char in fifo
                cRxBufferWritePtr++;            // increment pointer
                if ( cRxBufferWritePtr == ( cRxBuffer + RX_BUFFER_SIZE ) ) // pointer past end ?
                    {
                    cRxBufferWritePtr = cRxBuffer;      // set pointer to start of fifo
                    }
                cRxByteCnt++;              // Increment byte count
                if ( cChar == CR )
                    {
                    cRxMsgReady = YES;         // signal that message is ready
                    cReceiveFlag = NO;      // no more receive
                    }
                }
            }
        }
    done:;
    }

/*******************************************************************/

void main ( void )
    {
    char cX;

    delay_ms ( 200 );                   // wait enough time after Vdd rise
    iTimeOut = 1800;                    // preset to ~30 seconds
    iScreenRollCount = SCREEN_ROLL_COUNT;
    iButtonInactivityCount = BUTTON_INACTIVITY_COUNT;
    /* INITIALIZE */
    output_float ( RX_IN );             // ensure Rx input is HiZ
    output_float ( BUTTON_1 );          // ensure switch input is HiZ
    output_float ( BUTTON_2 );          // ensure switch input is HiZ
    output_float ( BUTTON_3 );          // ensure switch input is HiZ
    output_float ( PIN_A0 );            // set analog input pins to float
    output_float ( PIN_A1 );
    output_float ( PIN_A3 );
    port_b_pullups ( ON );              // enable pullups on switches

    // GET SAVED SETTINGS
    cContrast = read_eeprom ( ( long ) EEPROM_CONTRAST );        // get stored value
    output_bit ( LCD_BACKLITE, read_eeprom ( ( long ) EEPROM_BACKLIGHT ) );  // set backlight
    cScreenRoll = read_eeprom ( ( long ) EEPROM_SCREENROLL );     // get stored value
    cUsbConnection = read_eeprom ( ( long ) EEPROM_USB_PROTOCOL ); // get initial USB connection
    output_bit ( USB_NMEA_GARMIN, cUsbConnection );     // set the initial USB connection

    // PWM is for display contrast
    setup_ccp2 ( CCP_PWM );                     // set for PWM mode
    //The cycle time will be (1/clock)*4*t2div*(period+1)
    // 1/8000000 * 4 * 1 * 128 = 51.2uS = 19.5KHz
    setup_timer_2 ( T2_DIV_BY_1, 255, 1 );      // set PWM period
    // duty cycle = value*(1/clock)*t2div
    // 10 * 1/8000000 * 1 = 1.2uS
    set_pwm2_duty ( cContrast );                // set contrast duty cycle

    // SETUP TIMER 0
    // Need 8-bit Timer0 to roll over every 13mS, approximately.
    // Roll time = 256 * 1 / ( clock_freq / prescaler setting / 4 )
    #if CRYSTAL_FREQ >= 15000000
    setup_timer_0 ( RTCC_INTERNAL | RTCC_DIV_256 | RTCC_8_BIT );  // ~13mS timer wrap
    #elif CRYSTAL_FREQ >= 8000000
    setup_timer_0 ( RTCC_INTERNAL | RTCC_DIV_128 | RTCC_8_BIT );  // ~13mS timer wrap
    #elif CRYSTAL_FREQ < 8000000
    setup_timer_0 ( RTCC_INTERNAL | RTCC_DIV_64 | RTCC_8_BIT );  // ~13mS timer wrap
    #endif

    // Timer 1 roll time = 65536 * 1 / ( clock_freq / prescaler setting / 4 )
    setup_timer_1 ( T1_INTERNAL | T1_DIV_BY_8 );    // 16-bit timer

    setup_adc_ports ( RA0_RA1_RA3_ANALOG );  /* these three statements set up the ADC */
    setup_adc ( ADC_CLOCK_INTERNAL );
    cIllumination = OFF;

    // Setup CCP1 register for diesel tachometer
    setup_ccp1 ( CCP_CAPTURE_RE );     // capture every rising edge on CCP1

    LCD_Init();                        // set up LCD for 4-wire bus, etc.

    /* INIT MESSAGE */
    LCD_SetPosition ( LINE_1 + 0 );
    printf ( LCD_PutChar, "  \"Northern Light\"  " );   // welcome screen
    LCD_SetPosition ( LINE_2 + 2 );
    printf ( LCD_PutChar, "Systems Monitor " );
    LCD_SetPosition ( LINE_3 + 3 );
    printf ( LCD_PutChar, "v21f  08/11/06" );
    LCD_SetPosition ( LINE_4 + 5 );
    printf ( LCD_PutChar, "c Jon Fick" );
    delay_ms ( 1000 );

    // USB CONNECTION MESSAGE
    DisplayMessage ( USB_MSG );
    delay_ms ( 1000 );

    /* SETUP MODE */
    if ( input ( BUTTON_1 ) == LOW )  // if button is pressed
        {
        // SET DISPLAY CONTRAST
        LCD_PutCmd ( CLEAR_DISP );
        LCD_SetPosition ( LINE_1 + 0 );
        printf ( LCD_PutChar, "Set contrast:" );
        LCD_SetPosition ( LINE_2 + 0 );
        printf ( LCD_PutChar, "<-- More" );
        LCD_SetPosition ( LINE_3 + 0 );
        printf ( LCD_PutChar, "<-- DONE" );
        LCD_SetPosition ( LINE_4 + 0 );
        printf ( LCD_PutChar, "<-- Less" );
        while ( input ( BUTTON_1 ) == LOW );    // wait for switch to be released after entering SETUP mode
        cContrast = 120;          // start at near full contrast
        cDone = NO;
        while ( cDone == NO )
            {
            set_pwm2_duty ( cContrast );        // update contrast
            if ( input ( BUTTON_1 ) == LOW )
                {
                if ( cContrast > 100 )
                    {
                    cContrast--;            // more
                    }
                }
            if ( input ( BUTTON_2 ) == LOW )
                {
                cDone = YES;                // done
                }
            if ( input ( BUTTON_3 ) == LOW )
                {
                if ( cContrast < 165 )
                    {
                    cContrast++;        // less
                    }
                }
            delay_ms ( 30 );                   // autorepeat
            }
        write_eeprom ( ( long ) EEPROM_CONTRAST, cContrast );    // save CONTRAST to EEPROM
        // BOOTUP SCREEN
        LCD_PutCmd ( CLEAR_DISP );
        LCD_SetPosition ( LINE_2 + 0 );
        printf ( LCD_PutChar, "<- Press & hold " );
        LCD_SetPosition ( LINE_3 + 0 );
        printf ( LCD_PutChar, "   bootup screen" );
        while ( input ( BUTTON_1 ) == LOW );  // wait until button not pressed
        cX = POSITION_SCREEN;
        while ( TRUE )
            {
            LCD_SetPosition ( LINE_4 + 6 );
            switch ( cX )
                {
                case POSITION_SCREEN:
                    {
                    printf ( LCD_PutChar, "POSITION " );
                    break;
                    }
                case WAYPOINT_SCREEN:
                    {
                    printf ( LCD_PutChar, "WAYPOINT " );
                    break;
                    }
                case INST_SCREEN:
                    {
                    printf ( LCD_PutChar, "INSTRUMTS" );
                    break;
                    }
                case BATTERY_SCREEN:
                    {
                    printf ( LCD_PutChar, "BATTERY  " );
                    break;
                    }
                case TACH_SCREEN:
                    {
                    printf ( LCD_PutChar, "TACHOMETR" );
                    break;
                    }
                case TANK_SCREEN:
                    {
                    printf ( LCD_PutChar, "TANK LVL " );
                    break;
                    }
                }
            delay_ms ( 750 );
            if ( input ( BUTTON_1 ) == LOW )  // if button is pressed
                {
                LCD_SetPosition ( LINE_4 + 3 );
                printf ( LCD_PutChar, "OK--SAVED   " );
                write_eeprom ( ( long ) EEPROM_INITIAL, cX );     // save screen number to EEPROM
                while ( input ( BUTTON_1 ) == LOW );    // wait until button is released
                break;
                }
            if ( cX++ == INST_SCREEN )      // wrap
                {
                cX = POSITION_SCREEN;
                }
            }
        // BOOTUP BACKLIGHT
        LCD_PutCmd ( CLEAR_DISP );
        LCD_SetPosition ( LINE_2 + 0 );
        printf ( LCD_PutChar, "<- Press & hold " );
        LCD_SetPosition ( LINE_3 + 0 );
        printf ( LCD_PutChar, "   bootup backlight" );
        while ( input ( BUTTON_1 ) == LOW );  // wait until button not pressed
        cX = OFF;
        while ( TRUE )
            {
            LCD_SetPosition ( LINE_4 + 6 );
            switch ( cX )
                {
                case OFF:
                    {
                    printf ( LCD_PutChar, "OFF" );
                    break;
                    }
                case ON:
                    {
                    printf ( LCD_PutChar, "ON " );
                    break;
                    }
                }
            delay_ms ( 750 );
            if ( input ( BUTTON_1 ) == LOW )  // if button is pressed
                {
                LCD_SetPosition ( LINE_4 + 3 );
                printf ( LCD_PutChar, "OK--SAVED" );
                write_eeprom ( ( long ) EEPROM_BACKLIGHT, cX );   // save backlight to EEPROM
                while ( input ( BUTTON_1 ) == LOW );    // wait until button is released
                break;
                }
            cX ^= 1;      // wrap
            }
        // SCREEN ROLL
        LCD_PutCmd ( CLEAR_DISP );
        LCD_SetPosition ( LINE_2 + 0 );
        printf ( LCD_PutChar, "<- Press & hold " );
        LCD_SetPosition ( LINE_3 + 0 );
        printf ( LCD_PutChar, "   auto screen roll" );
        while ( input ( BUTTON_1 ) == LOW );  // wait until button not pressed
        cX = OFF;
        while ( TRUE )
            {
            LCD_SetPosition ( LINE_4 + 6 );
            switch ( cX )
                {
                case OFF:
                    {
                    printf ( LCD_PutChar, "OFF" );
                    break;
                    }
                case ON:
                    {
                    printf ( LCD_PutChar, "ON " );
                    break;
                    }
                }
            delay_ms ( 750 );
            if ( input ( BUTTON_1 ) == LOW )  // if button is pressed
                {
                LCD_SetPosition ( LINE_4 + 3 );
                printf ( LCD_PutChar, "OK--SAVED" );
                write_eeprom ( ( long ) EEPROM_SCREENROLL, cX );   // save backlight to EEPROM
                while ( input ( BUTTON_1 ) == LOW );    // wait until button is released
                break;
                }
            cX ^= 1;      // wrap
            }
        reset_cpu();
        }


    /* BUTTON ASSIGNMENT MESSAGE */
    LCD_PutCmd ( CLEAR_DISP );
    LCD_SetPosition ( LINE_1 + 0 );
    printf ( LCD_PutChar, "BUTTONS:" );
    LCD_SetPosition ( LINE_2 + 0 );
    printf ( LCD_PutChar, "<-- GPS & BackLight" );
    LCD_SetPosition ( LINE_3 + 0 );
    printf ( LCD_PutChar, "<-- Instruments" );
    LCD_SetPosition ( LINE_4 + 0 );
    printf ( LCD_PutChar, "<-- Systems" );
    delay_ms ( 2000 );

    /* This IF/ENDIF is a tool for getting the $GP... codes */
    /* that are used in the switch/case in the main loop. */
    #if ( GET_GPS_CODE == YES )
    printf ( LCD_PutChar, "%u", 'G'^'P'^'R'^'M'^'B');
    while ( TRUE );
    #endif

    /* INTERRUPTS */
    ext_int_edge ( H_TO_L );            // set falling edge ext interrupt
    enable_interrupts ( INT_TIMER1 );   // enable Timer1 interrupt
    enable_interrupts ( INT_RDA );      // enable serial interrupt
    enable_interrupts ( INT_RTCC );     // enable Timer0 interrupt
    enable_interrupts ( INT_AD );       // enable ADC interrupt
    enable_interrupts ( GLOBAL );       // enable all interrupts

    /* VARIABLES */
    iVar = NULL;                        // default, no variation yet
    cVarDir = SPACE;                    // default, no variation yet
    cRmcTimer1 = 255;                   // initialize to 52 seconds
    cRmcTimer2 = RMC_TIME;              // trigger forced RMC after 10 minutes
    cScreen = HIDDEN_RMC;               // default screen, get magnetic variation first
    cSavedScreen = read_eeprom ( ( long ) EEPROM_INITIAL ); // restore initial screen
    iLastRange = 65535;                 // make max by default
    strcpy ( cToFrom, "  " );           // blank by default
    cScreenChanged = YES;
    cIndicator = 0;
    cButton1Count = 0;
    cButton2Count = 0;
    cButton3Count = 0;
    cRxErrorFlag = OFF;
    cSwitch1State = 0;                  // default screen
    cSwitch2State = 0;                  // default screen
    cSwitch3State = 0;                  // default screen

    /* MAIN LOOP ****************************************************************************/
    while ( TRUE )
        {
        cNmeaDataTimeOut = 188;        // 188 * 16mS = 3 seconds
        switch ( cScreen )
            {
            case USB_SCREEN:
                {
                if ( cScreenChanged == YES )
                    {
                    cScreenChanged = NO;
                    cSkip = NO;
                    DisplayMessage ( USB_MSG );
                    }
                cScreen = cSavedScreen;         // revert to previous screen
                break;
                }
            case HIDDEN_RMC:
                {
                InitRxBuffer( GPRMC_CODE );     // set code and turn on serial interrupt
                while ( ( cRxMsgReady == NO ) && ( cNmeaDataTimeOut != 0 ) );
                disable_interrupts ( INT_RDA );         // ignore rest of messages
                if ( cNmeaDataTimeOut != 0 )            // if not timed out
                    {
                    GetUtcAndMagVar();             // get and store the magnetic variation
                    }
                cScreen = cSavedScreen;         // revert to previous screen
                break;
                }
            case POSITION_SCREEN:
                {
                if ( cScreenChanged == YES )
                    {
                    disable_interrupts ( INT_RDA );
                    cScreenChanged = NO;
                    cSkip = NO;
                    LCD_PutCmd ( CLEAR_DISP );
                    DisplayTemplateLatLon();
                    enable_interrupts ( INT_RDA );
                    }
                InitRxBuffer( GPRMC_CODE );     // set code and turn on serial interrupt
                while ( ( cRxMsgReady == NO ) && ( cNmeaDataTimeOut != 0 ) && ( cScreenChanged != YES ) );
                disable_interrupts ( INT_RDA );         // ignore rest of messages
                if ( cScreenChanged == NO )
                    {
                    if ( cNmeaDataTimeOut != 0 )
                        {
                        DisplayPosition();
                        }
                    else
                        {
                        DisplayMessage ( NODATA_MSG );
                        }
                    }
                cRxErrorFlag = OFF;
                ToggleActivityIndicator();
                break;
                }
            case WAYPOINT_SCREEN:
                {
                if ( cScreenChanged == YES )
                    {
                    disable_interrupts ( INT_RDA );
                    cScreenChanged = NO;
                    cSkip = NO;
                    LCD_PutCmd ( CLEAR_DISP );
                    DisplayTemplateWaypoint();
                    enable_interrupts ( INT_RDA );
                    }
                cSkip = NO;
                InitRxBuffer( GPRMB_CODE );     // set code and turn on serial interrupt
                while ( ( cRxMsgReady == NO ) && ( cNmeaDataTimeOut != 0 ) && ( cScreenChanged != YES ) );
                disable_interrupts ( INT_RDA );         // ignore rest of messages
                if ( cScreenChanged == NO )
                    {
                    if ( cNmeaDataTimeOut != 0 )
                        {
                        DisplayWaypoint();
                        }
                    else
                        {
                        DisplayMessage ( NODATA_MSG );
                        }
                    }
                ToggleActivityIndicator();
                break;
                }
            case INST_SCREEN:
                {
                if ( cScreenChanged == YES )
                    {
                    disable_interrupts ( INT_RDA );
                    cScreenChanged = NO;
                    cSkip = NO;
                    LCD_PutCmd ( CLEAR_DISP );
                    DisplayTemplateInstruments();
                    cSeatalkDisplay = INST_ACCUM_TIME;
                    }
                DisplayInstruments();
                break;
                }
            case BATTERY_SCREEN:
                {
                if ( cScreenChanged == YES )
                    {
                    disable_interrupts ( INT_RDA );
                    cScreenChanged = NO;
                    cSkip = NO;
                    LCD_PutCmd ( CLEAR_DISP );
                    DisplayTemplateAnalog();
                    }
                DisplayAnalog();
                break;
                }
            case TACH_SCREEN:
                {
                if ( cScreenChanged == YES )
                    {
                    disable_interrupts ( INT_RDA );
                    cScreenChanged = NO;
                    cSkip = NO;
                    LCD_PutCmd ( CLEAR_DISP );
                    DisplayTemplateTach();
                    }
                DisplayTach();
                break;
                }
            case TANK_SCREEN:
                {
                if ( cScreenChanged == YES )
                    {
                    disable_interrupts ( INT_RDA );
                    cScreenChanged = NO;
                    cSkip = NO;
                    LCD_PutCmd ( CLEAR_DISP );
                    DisplayTemplateTank();
                    }
                DisplayTank();
                break;
                }
            }
        // Preset timeout counter each loop; RTCC interrupt decrements, resets if zero is reached
        iTimeOut = 1800;     // ~ 30 seconds
        }
    }

/**********************************************************************************************/

#separate void ToggleActivityIndicator ( void )
    {
    char cX;

    /* Flashing activity indicator in lower right of screen. */
    cIndicator ^= 1;
    cX = cIndicator ? ACTIVITY_SYMBOL : SPACE;
    LCD_SetPosition ( LINE_4 + 19 );
    printf ( LCD_PutChar, "%c", cX );
    }

#separate void DisplayTemplateLatLon ( void )
    {
    LCD_SetPosition ( LINE_1 );
    printf ( LCD_PutChar, "Lat" );
    LCD_SetPosition ( LINE_2 );
    printf ( LCD_PutChar, "Lon" );
    LCD_SetPosition ( LINE_3 );
    printf ( LCD_PutChar, "Speed" );
    LCD_SetPosition ( LINE_4 );
    printf ( LCD_PutChar, "Heading" );
    }

#separate void DisplayTemplateWaypoint ( void )
    {
    LCD_SetPosition ( LINE_1 );
    printf ( LCD_PutChar, "Waypoint" );
    LCD_SetPosition ( LINE_2 );
    printf ( LCD_PutChar, "Steer" );
    LCD_SetPosition ( LINE_3 );
    printf ( LCD_PutChar, "Dist" );
    LCD_SetPosition ( LINE_4 );
    printf ( LCD_PutChar, "Bearing" );
    }

#separate void DisplayTemplateAnalog ( void )
    {
    LCD_SetPosition ( LINE_1 + 3 );
    printf ( LCD_PutChar, "BATTERY STATUS" );
    LCD_SetPosition ( LINE_2 );
    printf ( LCD_PutChar, "Primary" );
    LCD_SetPosition ( LINE_3 );
    printf ( LCD_PutChar, "Secondary" );
    LCD_SetPosition ( LINE_4 );
    printf ( LCD_PutChar, "Refrigerator" );
    }

#separate void DisplayPosition ( void )
    {
    SkipField ( 1 );   // skip UTC
    GetField();        // A = OK, V = warning
    if ( ( cC [ 0 ] == 'A' ) && ( !cSkip ) )
        {
        GetField();                   // LAT
        if ( !cSkip )
            {
            DisplayLatitude ( LINE_1 );
            }
        GetField();                   // LON
        if ( !cSkip )
            {
            DisplayLongitude ( LINE_2 );
            }
        GetField();                   // SPEED
        if ( !cSkip )
            {
            DisplaySpeed ( LINE_3 );
            }
        GetField();                   // HEADING
        if ( !cSkip )
            {
            DisplayHeading ( LINE_4 );
            }
        }
    else
        {
        DisplayMessage( WARNING_MSG );
        }
    }

#separate void DisplayWaypoint ( void )
    {
    char cX;

    GetField();        // A = OK, V = warning
    if ( ( cC [ 0 ] == 'A' ) && ( !cSkip ) )
        {
        cX = GetField();        // XTE
        if ( !cSkip )
            {
            DisplaySteer ( LINE_2, cX );
            }
        SkipField ( 1 );        // skip origin WP ID
        GetField();                     // DEST WP ID
        if ( !cSkip )
            {
            DisplayWaypointName ( LINE_1, cX );
            }
        SkipField ( 4 );        // skip LAT, NS, LON, EW
        cX = GetField();                     // RANGE
        if ( !cSkip )
            {
            DisplayDistance ( LINE_3, cX );
            }
        cX = GetField();                     // BEARING
        if ( !cSkip )
            {
            DisplayBearing ( LINE_4, cX );
            }
        SkipField ( 1 );        // skip SPEED TO DEST
        GetField();                     // ARRIVAL FLAG
        if ( !cSkip )
            {
            DisplayArrival ( LINE_1 );    // overwrite RANGE if arrived
            }
        }
    else
        {
        DisplayMessage( WARNING_MSG );
        }
    }

#separate void DisplayAnalog ( void )
    {
    long iX;
    char cCnt;

    set_adc_channel ( 0 );                      // set channel
    delay_us ( 100 );                           // wait aquisition time
    cAdcDone = NO;
    if ( !cSkip )
        {
        LCD_SetPosition ( LINE_2 + 13 );
        DisplayScaledVoltage ( read_adc(), MAX_VOLTS );
        printf ( LCD_PutChar, " V " );
        }
    set_adc_channel ( 1 );
    delay_us ( 100 );
    cAdcDone = NO;
    if ( !cSkip )
        {
        LCD_SetPosition ( LINE_3 + 13 );
        DisplayScaledVoltage ( read_adc(), MAX_VOLTS );
        printf ( LCD_PutChar, " V " );
        }
    set_adc_channel ( 3 );
    delay_us ( 100 );
    cAdcDone = NO;
    if ( !cSkip )
        {
        LCD_SetPosition ( LINE_4 + 13 );
        DisplayScaledVoltage ( read_adc(), MAX_VOLTS );
        printf ( LCD_PutChar, " V " );
        }
    Delay5mS ( 200 );                    // delay 1.0 second
    ToggleActivityIndicator();
    }

#separate void GetUtcAndMagVar ( void )
    {
    /*
    This is a non-display version of the RMC sentence
    to get the A/V warning, the magnetic variation, and the
    magnetic direction.
    */

    GetField();              // get UTC
    GetField();        // A = OK, V = warning
    if ( cC [ 0 ] == 'A' )
        {
        SkipField ( 7 );   // skip fields
        GetField();             // MAGNETIC VARIATION
        iVar = FieldFiveToLong();     // save to global variable, used in other sentences
        GetField();     // EW
        cVarDir = cC [ 0 ];     // save direction
        }
    else
        {
        iVar = NULL;              // invalid
        cVarDir = SPACE;
        }
    }

/******************************************************************/
#separate void DisplayScaledVoltage ( long iV, char cScale )
    {
    float fX;

    /*
    0 to 5V input at pin 2 results in 0 - 1023.  This routine
    scales it to something else.
    */
    while ( cAdcDone == NO );         // wait for completion by ADC interrupt
    if ( iV == 1023 )
        {
        printf ( LCD_PutChar, "O/L" );  /* print it to the screen */
        }
    else
        {
        fX = ( ( float ) iV ) / 1023 * ( float ) cScale;   // scale to proper range, 1023 leaves room for out-of-range
        printf ( LCD_PutChar, "%02.1f", fX );  /* print it to the screen */
        }
    }

#separate void DisplayArrival ( char cLine )
    {
    LCD_SetPosition ( cLine + 11 );
    if ( cC [ 0 ] == 'A' )
        {
        printf ( LCD_PutChar, "Arrived" );
        }
    else
        {
        printf ( LCD_PutChar, "       " );
        }
    }

#separate void DisplayWaypointName ( char cLine, char cX )
    {
    /* Displays waypoint name, pads field with blanks */
    char cChar, cI;

    LCD_SetPosition ( cLine );
    if ( cX != 0 )
        {
        printf ( LCD_PutChar, "\"" );
        for ( cI = 0; cI < 6; cI++ )
            {
            cChar = cC [ cI ];
            if ( cChar == EOF )
                {
                break;
                }
            printf ( LCD_PutChar, "%c", cChar );
            }
        printf ( LCD_PutChar, "\"" );
        // Blank remainder of field
        cChar = SPACE;
        for ( ; cI < 6; cI++ )
            {
            printf ( LCD_PutChar, "%c", cChar );
            }
        }
    else
        {
        printf ( LCD_PutChar, "- none -" );
        }
    }

#separate void DisplaySteer ( char cLine, char cX )
    {
    /*
    Displays A.BC literals, appends 'L' or 'R'.
    If less than 1.0, displays feet rather than nm.
    Doesn't display distance if on track.
    */
    long iX;
    char cCnt;

    if ( cX != 0 )
        {
        if ( ( cC [ 0 ] != '0' ) || ( cC [ 2 ] != '0' ) || ( cC [ 3 ] != '0' ) )   // if not 0.00
            {
            LCD_SetPosition ( cLine + 14 );
            printf ( LCD_PutChar, "      " );         // blank possible characters
            LCD_SetPosition ( cLine + 11 );
            if ( cC [ 0 ] == '0' )          // if less than 1.0 nm, display as feet
                {
                iX = ( 528 * ( long ) ( cC [ 2 ] - 0x30 ) ) + ( 52 * ( long ) ( cC [ 3 ] - 0x30 ) );
                printf ( LCD_PutChar, "%luft  ", iX );
                }
            else                             // if 1.0 nm or greater, display as nautical miles
                {
                printf ( LCD_PutChar, "%c%c%c%cmi  ", cC [ 0 ], cC [ 1 ], cC [ 2 ] , cC [ 3 ] );
                }
            GetField();              // L or R
            LCD_SetPosition ( cLine + 6 );
            if ( cC [ 0 ] == 'L' )
                {
                printf ( LCD_PutChar, "PORT " );
                }
            else
                {
                printf ( LCD_PutChar, "STBD " );
                }
            }
        else           // if 0.00
            {
            LCD_SetPosition ( cLine + 11 );
            printf ( LCD_PutChar, "On track " );
            GetField();              // dummy L or R
            }
        }
    else
        {
        LCD_SetPosition ( cLine + 6 );
        printf ( LCD_PutChar, "              " );
        }
    }

#separate void DisplayDistance ( char cLine, char cX )
    {
    /* Format: ABC.D nautical miles */
    char cChar, cI;
    long iThisRange;

    if ( cX != 0 )           // if waypoint data to display
        {
        LCD_SetPosition ( cLine + 11 );
        cI = 0;
        for ( cI = 0; cI < 2; cI++ )    // find first non-zero
            {
            cChar = cC [ cI ];
            if ( cChar != '0' )
                {
                break;
                }
            }
        for ( ; cI < 5; cI++ )    // display from there on
            {
            printf ( LCD_PutChar, "%c", cC [ cI ] );
            }
        printf ( LCD_PutChar, "nm  " );     // pad with blanks

        /*
        The least significant character from the GPS is 0.1 nm.
        Multiply whole thing by 10 and make it type long.
        Discern if increasing (FROM) or decreasing (TO).
        */
        iThisRange = 1000 * ( long ) ( cC [ 0 ] - 0x30 );
        iThisRange += 100 * ( long ) ( cC [ 1 ] - 0x30 );
        iThisRange += 10 * ( long ) ( cC [ 2 ] - 0x30 );
        iThisRange += ( long ) ( cC [ 4 ] - 0x30 );
        if ( iThisRange < iLastRange )
            {
            strcpy ( cToFrom, "TO  " );
            }
        if ( iThisRange > iLastRange )
            {
            strcpy ( cToFrom, "FROM" );
            }
        iLastRange = iThisRange;    // save this range to compare next time
        LCD_SetPosition ( cLine + 5 );
        printf ( LCD_PutChar, cToFrom );
        }
    else
        {
        LCD_SetPosition ( cLine + 5 );
        printf ( LCD_PutChar, "               " );
        }
    }

#separate void DisplayBearing ( char cLine, char cX )
    {
    /*
    Compass variation comes from RMC sentence.  If RMC has not run yet
    then "T" is displayed after bearing.
    */
    long iHdg;
    char cTrueIndicator;

    if ( cX != 0 )           // if waypoint data to display
        {
        LCD_SetPosition ( cLine + 11 );
        //iHdg = FieldFiveToLong();   // exceeds stack depth ???
        JustifyDecimalPoint();
        iHdg = 100 * ( long ) ( cC [ 0 ] - 0x30 );
        iHdg += 10 * ( long ) ( cC [ 1 ] - 0x30 );
        iHdg += ( long ) ( cC [ 2 ] - 0x30 );
        if ( ( cC [ 3 ] == PERIOD ) && ( cC [ 4 ] >= '5' ) )
            {
            iHdg++;           // round up
            }

        iHdg = TrueToMag ( iHdg );    // factor variation into heading
        if ( ( iVar == NULL ) || ( cVarDir == SPACE ) )
            {
            cTrueIndicator = 'T';
            }
        else
            {
            cTrueIndicator = ' ';
            }
        printf ( LCD_PutChar, "%lu%c%c  ", iHdg, DEGREE, cTrueIndicator );   // pad with blanks
        }
    else
        {
        LCD_SetPosition ( cLine + 11 );
        printf ( LCD_PutChar, "         " );
        }
    }

#separate void DisplayLatitude ( char cLine )
    {
    /* Displays latitude ABCD.EFG as AB CD.EFG, appends 'N' or 'S' */
    LCD_SetPosition ( cLine + 8 );
    if ( cC [ 0 ] == '0' )
        {
        cC [ 0 ] = SPACE;
        }
    printf ( LCD_PutChar, "%c%c%c", cC [ 0 ], cC [ 1 ], DEGREE );
    printf ( LCD_PutChar, "%c%c%c%c%c%c", cC [ 2 ], cC [ 3 ], cC [ 4 ], cC [ 5 ], cC [ 6 ], cC [ 7 ] );
    GetField();              // NS
    printf ( LCD_PutChar, " %c", cC [ 0 ] );
    }

#separate void DisplayLongitude ( char cLine )
    {
    /* Displays longitude ABCDE.FGH as ABC DE.FGH, appends 'E' or 'W' */
    LCD_SetPosition ( cLine + 7 );
    if ( cC [ 0 ] == '0' )
        {
        cC [ 0 ] = SPACE;
        }
    if ( cC [ 1 ] == '0' )
        {
        cC [ 1 ] = SPACE;
        }
    printf ( LCD_PutChar, "%c%c%c%c", cC [ 0 ], cC [ 1 ], cC [ 2 ], DEGREE );
    printf ( LCD_PutChar, "%c%c%c%c%c%c", cC [ 3 ], cC [ 4 ], cC [ 5 ], cC [ 6 ], cC [ 7 ], cC [ 8 ] );
    GetField();              // EW
    printf ( LCD_PutChar, " %c", cC [ 0 ] );
    }

#separate void DisplaySpeed ( char cLine )
    {
    float fX;
    char cLoc;

    LCD_SetPosition ( cLine + 8 );
    JustifyDecimalPoint();
    fX = 100 * ( cC [ 0 ] - 0x30 );
    fX += 10 * ( cC [ 1 ] - 0x30 );
    fX += 1 * ( cC [ 2 ] - 0x30 );
    fX += 0.1 * ( cC [ 4 ] - 0x30 );
    #if SPEED_UNITS == 2
    fX *= 1.852;        // convert knots to km/h
    #endif
    #if SPEED_UNITS == 3
    fX *= 1.151;        // convert knots to mi/h
    #endif
    printf ( LCD_PutChar, "%03.1f ", fX );  // print it to the screen
    #if SPEED_UNITS == 1
    printf ( LCD_PutChar, "kts    " );     // print it to the screen
    #endif
    #if SPEED_UNITS == 2
    printf ( LCD_PutChar, "kph    " );     // print it to the screen
    #endif
    #if SPEED_UNITS == 3
    printf ( LCD_PutChar, "mph    " );     // print it to the screen
    #endif
    }

#separate void DisplayHeading ( char cLine )
    {
    long iHdg;

    LCD_SetPosition ( cLine + 8 );
    //iHdg = FieldFiveToLong();    // exceeds stack depth ???

    JustifyDecimalPoint();
    iHdg = 100 * ( long ) ( cC [ 0 ] - 0x30 );
    iHdg += 10 * ( long ) ( cC [ 1 ] - 0x30 );
    iHdg += ( long ) ( cC [ 2 ] - 0x30 );
    if ( ( cC [ 3 ] == PERIOD ) && ( cC [ 4 ] >= '5' ) )
        {
        iHdg++;           // round up
        }

    SkipField ( 1 );     // skip fix date
    GetField();             // MAGNETIC VARIATION
    //iVar = FieldFiveToLong();     // save to global variable, used in other sentences  // exceeds stack depth ???

// presently looks for format: 016.2
// now gets 16.2

    JustifyDecimalPoint();
    iVar = 100 * ( long ) ( cC [ 0 ] - 0x30 );
    iVar += 10 * ( long ) ( cC [ 1 ] - 0x30 );
    iVar += ( long ) ( cC [ 2 ] - 0x30 );
    if ( ( cC [ 3 ] == PERIOD ) && ( cC [ 4 ] >= '5' ) )
        {
        iVar++;           // round up
        }

    GetField();     // EW
    cVarDir = cC [ 0 ];     // save direction
    iHdg = TrueToMag ( iHdg );    // factor variation into heading
    printf ( LCD_PutChar, "%lu%c  ", iHdg, DEGREE );    // pad with blanks
    }

#separate long FieldFiveToLong ( void )
    {
    /* Converts ABC.D to long, rounds decimal up or down */
    long iX;

    iX = 100 * ( long ) ( cC [ 0 ] - 0x30 );
    iX += 10 * ( long ) ( cC [ 1 ] - 0x30 );
    iX += ( long ) ( cC [ 2 ] - 0x30 );
    if ( ( cC [ 3 ] == PERIOD ) && ( cC [ 4 ] >= '5' ) )
        {
        iX++;           // round up
        }
    return ( iX );
    }

#separate void JustifyDecimalPoint ( void )
    {
    // Move the decimal point into position 3
    if ( cC [ 1 ] == PERIOD )        // i.e. "1.2" becomes  001.2
        {
        cC [ 4 ] = cC [ 2 ];
        cC [ 3 ] = cC [ 1 ];
        cC [ 2 ] = cC [ 0 ];
        cC [ 1 ] = '0';
        cC [ 0 ] = '0';
        }
    // Move the decimal point into position 3
    if ( cC [ 2 ] == PERIOD )        // i.e. "12.3" becomes 012.3
        {
        cC [ 4 ] = cC [ 3 ];
        cC [ 3 ] = cC [ 2 ];
        cC [ 2 ] = cC [ 1 ];
        cC [ 1 ] = cC [ 0 ];
        cC [ 0 ] = '0';
        }
    }

#separate long TrueToMag ( long iH )
    {
    /* Magnetic variation information comes from the RMC sentence */

    if ( cVarDir == 'W' )
        {
        iH += iVar;
        }
    else
        {
        if ( iH >= iVar )
            {
            iH -= iVar;     // OK as-is
            }
        else
            {
            iH = iH + 360 - iVar;   // correct for below zero
            }
        }
    if ( iH >= 360 )
        {
        iH -= 360;
        }
    return ( iH );
    }

#separate void DisplayMessage ( char cMsgNum )
    {
    LCD_PutCmd ( CLEAR_DISP );
    LCD_SetPosition ( LINE_2 );
    switch ( cMsgNum )
        {
        case WARNING_MSG:
            {
            printf ( LCD_PutChar,     "    GPS warning   " );
            break;
            }
        case NODATA_MSG:
            {
            if ( cRxErrorFlag == OFF )    // is it a framing error problem ?
                {
                printf ( LCD_PutChar, "  No data from GPS" );
                }
            else
                {
                printf ( LCD_PutChar, "     Baud error" );
                cRxErrorFlag = OFF;
                }
            break;
            }
        case USB_MSG:
            {
            printf ( LCD_PutChar, "   USB protocol:" );
            LCD_SetPosition ( LINE_3 );
            if ( cUsbConnection == NMEA_CONNECTED )
                {
                printf ( LCD_PutChar, "       GARMIN" );
                }
            else
                {
                printf ( LCD_PutChar, "        NMEA" );
                }
            write_eeprom ( ( long ) EEPROM_USB_PROTOCOL, cUsbConnection );
            break;
            }
        }
    Delay5mS ( 255 );                   // delay 1.25 seconds
    iVar = NULL;
    cVarDir = SPACE;                     // signal "no magnetic variation" yet
    cScreenChanged = YES;
    }

#separate void Delay5mS ( char cCnt )
    {
    char cX;

    /* This variable-count 5mS delay is interruptable by a button press */
    for ( cX = 0; cX < cCnt; cX++ )
        {
        if ( cScreenChanged == YES )
            {
            break;
            }
        delay_ms ( 5 );
        }
    }

#separate char GetField ( void )
    {
    char cX, cIndex;

    cX = NULL;
    cIndex = 0;
    while ( !cSkip )
        {
        cX = GetRxChar();
        if ( ( cX == COMMA ) || ( cX == CR ) )
            {
            break;
            }
        cC [ cIndex++ ] = cX;
        }
    cC [ cIndex ] = EOF;
    return ( cIndex );         // return number of characters in field
    }

#separate void SkipField ( char cCnt )
    {
    char cX;

    for ( cX = 0; cX < cCnt; cX++ )
        {
        while ( GetRxChar() != COMMA );
        }
    }

/* DIESEL TACHOMETER FUNCTIONS ========================================= */

#separate void DisplayTemplateTach ( void )
    {
    LCD_SetPosition ( LINE_1 + 1 );
    printf ( LCD_PutChar, "DIESEL TACHOMETER" );
    }

#separate void DisplayTach ( void )
    {
    char cCnt;
    float fRpm;
    int32 int32Count;

    enable_interrupts ( INT_CCP1 );     // CCP1 interrupt

    cTachState = DONE_TACH;
    if ( !cSkip )                           // do until button is pressed
        {
        int32Count = 0;
        for ( cCnt = 0; cCnt < 100; cCnt++ )    // accumulate 100 readings
            {
            cTachState = START_TACH;           // allow interrupt to start
            while ( cTachState != DONE_TACH )  // wait for timing to complete
                {
                if ( cSkip )
                    {
                    break;
                    }
                if ( get_timer1() > 60000 )  // timeout counter
                    {
                    iTachCount = 0;          // zero everything out
                    int32Count = 0;
                    break;                   // don't wait any longer
                    }
                }
            int32Count += ( int32 ) iTachCount;    // otherwise accumulate
            }
        int32Count /= 100;                // get average of those 100 readings
        fRpm = 1 / ( float ) int32Count; // period in uS
        fRpm *= 1000000;                 // period in seconds
        fRpm *= 60;                      // period in minutes
        fRpm /= ALTERNATOR_POLES;        // adjust for number of poles in alternator
        fRpm *= PULLEY_FACTOR;           // adjust for pulley ratio
        if ( int32Count == 0 )
            {
            LCD_SetPosition ( LINE_3 + 5 );
            printf ( LCD_PutChar, "Engine OFF" );
            }
        else
            {
            LCD_SetPosition ( LINE_3 + 5 );
            printf ( LCD_PutChar, " %4.0f RPM   ", fRpm );
            }
        }
    disable_interrupts ( INT_CCP1 );     // CCP1 interrupt
    Delay5mS ( 200 );                    // delay 1.0 seconds
    ToggleActivityIndicator();
    }

/* SEATALK COMMON FUNCTIONS ========================================= */

#separate char ReceiveSeatalkMsg ( void )
    {
    char cCnt, cCharPtr, cMaxCnt;

    iSeatalkTimeout0 = 61;                          // set first character for ~1 second timeout
    // FIRST CHARACTER
    while ( TRUE )              // wait until idle state
        {
        if ( !kbhit ( 2 ) )
            {
            break;
            }
        if ( ( iSeatalkTimeout0 == 0 ) || ( cSkip ) )
            {
            return ( SEATALK_TIMEOUT );
            }
        }
    while ( TRUE )              // wait until start edge, then get character
        {
        if ( kbhit ( 2 ) )                              // if character is ready
            {
            cSeatalkChar [ 0 ] = fgetc ( 2 );            // store first character in array
            if ( bit_test ( rs232_errors, NINTH_BIT ) == HIGH ) // if it is the command character
                {
                break;                              // found cmd char, get remainder
                }
            }
        if ( ( iSeatalkTimeout0 == 0 ) || ( cSkip ) )  // if timed out or key pressed
            {
            return ( SEATALK_TIMEOUT );             // return
            }
        }
    // REMAINING CHARACTERS
    while ( TRUE )              // get remaining characters
        {
        cMaxCnt = 17;                               // last possible character location (18th)
        for ( cCharPtr = 1; cCharPtr < cMaxCnt; cCharPtr++ )    // from second to nth data character
            {
            for ( cCnt = 0;; cCnt++ )               // set new inter-character counter
                {
                if ( kbhit ( 2 ) )                      // if character is ready
                    {
                    break;                          // jump out of for loop
                    }
                delay_us ( 10 );                    // wait for fractional bit period ( 1/21th bit)
                }
            if ( cCnt >= 230 )                      // if timed out beyond one character period
                {
                return ( SEATALK_DATA_ERROR );      // waited too long for character, must be collision, leave
                }
            cSeatalkChar [ cCharPtr ] = fgetc ( 2 );     // store character in array
            if ( cCharPtr == 1 )                    // if this is the character count byte
                {
                cMaxCnt = ( cSeatalkChar [ 1 ] & 0x0f ) + 3; // modify byte count of this message (low nibble)
                }
            if ( bit_test ( rs232_errors, NINTH_BIT ) != LOW )     // if 9th bit is not low, it's not a data character
                {
                return ( SEATALK_DATA_ERROR );       // return
                }
            if ( cSkip )                             // if key was pressed, skip out
                {
                return ( SEATALK_DATA_ERROR );       // return
                }
            }
        return ( SEATALK_OK );                      // return no errors
        }
    }

/* SEATALK TANK LEVEL FUNCTIONS ============================================= */

#separate void DisplayTemplateTank ( void )
    {
    LCD_SetPosition ( LINE_1 + 0 );
    printf ( LCD_PutChar, "TANK LEVELS" );
    LCD_SetPosition ( LINE_2 + 0 );
    printf ( LCD_PutChar, "Water-Bow:" );
    LCD_SetPosition ( LINE_3 + 0 );
    printf ( LCD_PutChar, "Water-Aft:" );
    LCD_SetPosition ( LINE_4 + 0 );
    printf ( LCD_PutChar, "Waste:" );
    iSeatalkTimeout1 = 0;    // start timeout timers at "timed out"
    iSeatalkTimeout2 = 0;
    iSeatalkTimeout3 = 0;
    }

#separate void DisplayTank ( void )
    {
    char cStatus;

    if ( !cSkip )                               // do until button is pressed
        {
        if ( cSeatalkDisplay != 0 )         // if not time to display yet
            {
            cStatus = ReceiveSeatalkMsg();
            if ( cStatus == SEATALK_OK )            // if no errors
                {
                switch ( cSeatalkChar [ 0 ] )
                    {
                    case TANK_MSGNUM:
                        {
                        switch ( cSeatalkChar [ TANK_ADR ] & 0x03 )      // mask on address bits 0 & 1
                            {
                            case 0x00:
                                {
                                cTankLevel0 = cSeatalkChar [ TANK_LEVEL ];
                                iSeatalkTimeout1 = SEATALK_RESET_TIME;
                                break;
                                }
                            case 0x01:
                                {
                                cTankLevel1 = cSeatalkChar [ TANK_LEVEL ];
                                iSeatalkTimeout2 = SEATALK_RESET_TIME;
                                break;
                                }
                            case 0x02:
                                {
                                cTankLevel2 = cSeatalkChar [ TANK_LEVEL ];
                                iSeatalkTimeout3 = SEATALK_RESET_TIME;
                                break;
                                }
                            }
                        }
                    }
                }
            }
        else
            {
            ToggleActivityIndicator();
            // Display Tank 0
            LCD_SetPosition ( LINE_2 + 11 );
            if ( iSeatalkTimeout1 == 0 )
                {
                WriteBlanks ( 8 );
                }
            else
                {
                printf ( LCD_PutChar, "%3u%%   ", cTankLevel0 );
                }
            // Display Tank 1
            LCD_SetPosition ( LINE_3 + 11 );
            if ( iSeatalkTimeout2 == 0 )
                {
                WriteBlanks ( 8 );
                }
            else
                {
                printf ( LCD_PutChar, "%3u%%   ", cTankLevel1 );
                }
            // Display Tank 2
            LCD_SetPosition ( LINE_4 + 11 );
            if ( iSeatalkTimeout3 == 0 )
                {
                WriteBlanks ( 8 );
                }
            else
                {
                printf ( LCD_PutChar, "%3u%%   ", cTankLevel2 );
                }
            cSeatalkDisplay = INST_ACCUM_TIME;     // reset
            }
        }
    }

/* SEATALK INSTRUMENTS FUNCTIONS =================================== */

#separate void DisplayTemplateInstruments ( void )
    {
    LCD_SetPosition ( LINE_1 + 0 );
    printf ( LCD_PutChar, "Depth" );
    LCD_SetPosition ( LINE_2 + 0 );
    printf ( LCD_PutChar, "Speed" );
    LCD_SetPosition ( LINE_3 + 0 );
    printf ( LCD_PutChar, "Compass" );
    LCD_SetPosition ( LINE_4 + 0 );
    printf ( LCD_PutChar, "WaterTemp" );
    iSeatalkTimeout1 = 0;    // start timeout timers at "timed out"
    iSeatalkTimeout2 = 0;
    iSeatalkTimeout3 = 0;
    iSeatalkTimeout4 = 0;
    }

#separate void DisplayInstruments ( void )
    {
    char cStatus, cX;
    long iX, iT;
    float fX;

    //LCD_SetPosition ( LINE_1 + 10 );
    //printf ( LCD_PutChar, "%0x%0x%0x%0x", cSeatalkChar[0],cSeatalkChar[1],cSeatalkChar[2],cSeatalkChar[3] );

    if ( !cSkip )                               // do until button is pressed
        {
        if ( cSeatalkDisplay != 0 )             // if not time to display yet
            {
            cStatus = ReceiveSeatalkMsg();
            if ( cStatus == SEATALK_OK )            // if no errors
                {
                switch ( cSeatalkChar [ 0 ] )
                    {
                    case DEPTH_MSGNUM:
                        {
                        cInstDepthHi = cSeatalkChar [ 4 ];
                        cInstDepthLo = cSeatalkChar [ 3 ];
                        iSeatalkTimeout1 = SEATALK_RESET_TIME;
                        break;
                        }
                    case SPEED_MSGNUM:
                        {
                        cInstSpeedHi = cSeatalkChar [ 3 ];
                        cInstSpeedLo = cSeatalkChar [ 2 ];
                        iSeatalkTimeout2 = SEATALK_RESET_TIME;
                        break;
                        }
                    case HEADING_MSGNUM:
                        {
                        cInstHeadingHi = cSeatalkChar [ 2 ];
                        cInstHeadingLo = cSeatalkChar [ 1 ];
                        iSeatalkTimeout3 = SEATALK_RESET_TIME;
                        break;
                        }
                    case TEMP_MSGNUM:
                        {
                        cInstTempHi = cSeatalkChar [ 3 ];
                        cInstTempLo = cSeatalkChar [ 2 ];
                        iSeatalkTimeout4 = SEATALK_RESET_TIME;
                        break;
                        }
                    }
                }
            }
        else
            {
            ToggleActivityIndicator();
            // Display depth
            iX = ( ( long ) cInstDepthHi * 256 ) + cInstDepthLo;
            fX = ( ( float ) iX ) / 10;
            LCD_SetPosition ( LINE_1 + 10 );
            if ( iSeatalkTimeout1 == 0 )
                {
                WriteBlanks ( 8 );
                }
            else
                {
                printf ( LCD_PutChar, "%3.1f ft ", fX );
                }
            // Display Speed
            iX = ( ( long ) cInstSpeedHi * 256 ) + cInstSpeedLo;
            fX = ( ( float ) iX ) / 10;
            LCD_SetPosition ( LINE_2 + 10 );
            if ( iSeatalkTimeout2 == 0 )
                {
                WriteBlanks ( 8 );
                }
            else
                {
                printf ( LCD_PutChar, "%01.1f kt ", fX );
                }
            // Display Heading
            // 9c 41 19 00 = 50 deg
            iX = ( long ) ( ( cInstHeadingLo >> 4 ) & 0x03 );
            iT = iX * 90;
            iX = ( long ) ( cInstHeadingHi & 0x3f );
            iT = iT + ( iX * 2 );
            iX = ( long ) ( ( cInstHeadingLo >> 4 ) & 0x0C );
            iT = iT + ( iX / 8 );
            LCD_SetPosition ( LINE_3 + 10 );
            if ( iSeatalkTimeout3 == 0 )
                {
                WriteBlanks ( 8 );
                }
            else
                {
                printf ( LCD_PutChar, "%03lu%c ", iT, DEGREE );
                if ( ( iT > 338 ) || ( iT <= 22 ) )
                    {
                    printf ( LCD_PutChar, "N " );
                    }
                if ( ( iT > 23 ) && ( iT <= 67 ) )
                    {
                    printf ( LCD_PutChar, "NE" );
                    }
                if ( ( iT > 68 ) && ( iT <= 112 ) )
                    {
                    printf ( LCD_PutChar, "E " );
                    }
                if ( ( iT > 113 ) && ( iT <= 157 ) )
                    {
                    printf ( LCD_PutChar, "SE" );
                    }
                if ( ( iT > 158 ) && ( iT <= 202 ) )
                    {
                    printf ( LCD_PutChar, "S " );
                    }
                if ( ( iT > 203 ) && ( iT <= 247 ) )
                    {
                    printf ( LCD_PutChar, "SW" );
                    }
                if ( ( iT > 248 ) && ( iT <= 292 ) )
                    {
                    printf ( LCD_PutChar, "W " );
                    }
                if ( ( iT > 293 ) && ( iT <= 337 ) )
                    {
                    printf ( LCD_PutChar, "NW" );
                    }
                }
            // Display Water Temperature
            //27 01 06 01 = 61F   also   23 01 10 e5 = 61F
            iX = ( ( long ) cInstTempHi * 256 ) + cInstTempLo;
            fX = ( ( float) iX - 100 ) / 10;             // centigrade
            fX = ( ( 9 * fX ) / 5 ) + 32;       // fahrenheit
            LCD_SetPosition ( LINE_4 + 10 );
            if ( iSeatalkTimeout4 == 0 )
                {
                WriteBlanks ( 8 );
                }
            else
                {
                printf ( LCD_PutChar, "%2.0f%cF   ", fX, DEGREE );
                }
            cSeatalkDisplay = INST_ACCUM_TIME;                     // reset
            }
        }
    }

#separate void WriteBlanks ( char cCnt )
    {
    char cX;

    for ( cX = 0; cX < cCnt; cX++ )
        {
        printf ( LCD_PutChar, " " );
        }
    }

/* RS232 FUNCTIONS ================================================== */

#separate void InitRxBuffer ( char cCode )
    {
    disable_interrupts ( INT_RDA );
    cRxBufferWritePtr = cRxBuffer;      // point to beginning of buffer
    cRxBufferReadPtr = cRxBuffer;
    cRxByteCnt = 0;
    cRxIsrState = 0;
    cRxMsgReady = NO;
    cRxMsgTypeDesired = cCode;
    enable_interrupts ( INT_RDA );
    }

#separate char GetRxChar ( void )
    {
    // Get the next available byte in the recv fifo.
    // Call this function ONLY if the recv fifo contains data.
    char cValue;

    cValue = 0;
    if ( cRxByteCnt > 0 )       // For safety, check if there is any data
        {
        cValue = *cRxBufferReadPtr++;     // Read byte from fifo
        if ( cRxBufferReadPtr == ( cRxBuffer + RX_BUFFER_SIZE ) ) // Did tail ptr wrap ?
            {
            cRxBufferReadPtr = cRxBuffer;    // If so, reset it to start of buffer
            }
        cRxByteCnt--; // Decrement byte count
        }
    return ( cValue );
    }

/* LCD FUNCTIONS ================================= */

#separate void LCD_Init ( void )
    {
    LCD_SetData ( 0x00 );
    delay_ms ( 200 );       /* wait enough time after Vdd rise */
    output_low ( LCD_RS );
    LCD_SetData ( 0x03 );   /* init with specific nibbles to start 4-bit mode */
    LCD_PulseEnable();
    LCD_PulseEnable();
    LCD_PulseEnable();
    LCD_SetData ( 0x02 );   /* set 4-bit interface */
    LCD_PulseEnable();      /* send dual nibbles hereafter, MSN first */
    LCD_PutCmd ( 0x2C );    /* function set (all lines, 5x7 characters) */
    LCD_PutCmd ( 0x0C );    /* display ON, cursor off, no blink */
    LCD_PutCmd ( 0x01 );    /* clear display */
    LCD_PutCmd ( 0x06 );    /* entry mode set, increment & scroll left */
    }

#separate void LCD_SetPosition ( unsigned int cX )
    {
    LCD_SetData ( swap ( cX ) | 0x08 );
    LCD_PulseEnable();
    LCD_SetData ( swap ( cX ) );
    LCD_PulseEnable();
    }

#separate void LCD_PutChar ( unsigned int cX )
    {
    if ( !cSkip )
        {
        output_high ( LCD_RS );
        LCD_SetData ( swap ( cX ) );     /* send high nibble */
        LCD_PulseEnable();
        LCD_SetData ( swap ( cX ) );     /* send low nibble */
        LCD_PulseEnable();
        output_low ( LCD_RS );
        }
    }

#separate void LCD_PutCmd ( unsigned int cX )
    {
    LCD_SetData ( swap ( cX ) );     /* send high nibble */
    LCD_PulseEnable();
    LCD_SetData ( swap ( cX ) );     /* send low nibble */
    LCD_PulseEnable();
    }

#separate void LCD_PulseEnable ( void )
    {
    output_high ( LCD_EN );
    delay_us ( 3 );         // was 10
    output_low ( LCD_EN );
    delay_ms ( 3 );         // was 5
    }

#separate void LCD_SetData ( unsigned int cX )
    {
    output_bit ( LCD_D4, cX & 0x01 );
    output_bit ( LCD_D5, cX & 0x02 );
    output_bit ( LCD_D6, cX & 0x04 );
    output_bit ( LCD_D7, cX & 0x08 );
    }