pic_wordclock.c

/*  
 *  WORD CLOCK - pic_wordclock.c
 *  ----------------------------
 *  Tells the time using words.
 *
 *  by:
 *  - Simone Stefani, @SimoneStefani
 *  - Marcel Eschmann, @eschmar
 *
 *  Compiler:
 *  B Knudsen Cc5x C-compiler - not ANSI-C
 */

#include "16F690.h"
#include "int16Cxx.h"
#pragma config |= 0x00D4

/*
 *  CONFIGURATION
 *  -------------
 *
 *  00 - "IT" - Hardwired
 *  01 - "IS" - Hardwired
 *
 *  02 - VSR0.0 - "TEN"
 *  03 - VSR0.1 - "HALF"
 *  04 - VSR0.2 - "QUARTER"
 *  05 - VSR0.3 - "TWENTY"
 *  06 - VSR0.4 - "FIVE"
 *
 *  07 - VSR0.5 - "MINUTES"
 *  08 - VSR0.6 - "PAST"
 *  09 - VSR1.0 - "TO"
 *
 *  10 - VSR1.1 - "ONE"
 *  11 - VSR1.2 - "TWO"
 *  12 - VSR1.3 - "THREE"
 *  13 - VSR1.4 - "FOUR"
 *  14 - VSR1.5 - "FIVE"
 *  15 - VSR1.6 - "SIX"
 *  16 - VSR2.0 - "SEVEN"
 *  17 - VSR2.1 - "EIGHT"
 *  18 - VSR2.2 - "NINE"
 *  19 - VSR2.3 - "TEN"
 *  20 - VSR2.4 - "ELEVEN"
 *  21 - VSR2.5 - "TWELVE"
 *  22 - VSR2.6 - "OCLOCK"
 */

#define MTEN    VSR0.0 = 1
#define HALF    VSR0.1 = 1
#define QUARTER VSR0.2 = 1
#define TWENTY  VSR0.3 = 1
#define MFIVE   VSR0.4 = 1
#define MINUTES VSR0.5 = 1
#define PAST    VSR0.6 = 1
#define PEW0    VSR0.7 = 1
#define TO      VSR1.0 = 1
#define ONE     VSR1.1 = 1
#define TWO     VSR1.2 = 1
#define THREE   VSR1.3 = 1
#define FOUR    VSR1.4 = 1
#define HFIVE   VSR1.5 = 1
#define SIX     VSR1.6 = 1
#define PEW1    VSR1.7 = 1
#define SEVEN   VSR2.0 = 1
#define EIGHT   VSR2.1 = 1
#define NINE    VSR2.2 = 1
#define HTEN    VSR2.3 = 1
#define ELEVEN  VSR2.4 = 1
#define TWELVE  VSR2.5 = 1
#define OCLOCK  VSR2.6 = 1
#define PEW2    VSR2.7 = 1
 
/**
 * Shift Register Pins
 */
#define DATA_PORT       PORTC.0
#define CLOCK_PORT      PORTC.1
#define STROBE_PORT     PORTC.2
#define MINUTES_BUTTON  PORTC.5
#define HOURS_BUTTON    PORTC.4

/**
 * Functions
 */
void increaseClock(void);
void increaseClockByHour(void);
void shiftOut(char val);
void shiftOutSingle(int b);
void initPorts(void);
void initTimer0Interrupt(void);
void updateShiftRegisters(void);
void updateView(void);
void turnOffLeds(void);

/**
 * Timing / Variables
 */
#define TIMERVALUE  125
#define POSTSCALER1 61
#define POSTSCALER2 15
int unsigned postScaler;
int unsigned postPostScaler;

int unsigned state_minutes;
int unsigned state_hours;
int VSR0, VSR1, VSR2; // shift register X

/**
 * Interrupt service routine
 */
#pragma origin 4
interrupt Timer0_ISR(void) {
    int_save_registers
    
    postScaler += 1;
    postScaler = postScaler % POSTSCALER1;

    int delay;
    delay = postScaler % 3;

    // Read hour button input
    if (HOURS_BUTTON && delay == 0) {
        nop2();
        increaseClockByHour();
        turnOffLeds();
        updateShiftRegisters();
        updateView();
        nop2();
    }
    
    // Read minute button input
    if (MINUTES_BUTTON && delay == 0) {
        nop2();
        increaseClock();
        turnOffLeds();
        updateShiftRegisters();
        updateView();
        nop2();
    }

    // Update clock
    if (postScaler == 0) {
        postPostScaler += 1;
        postPostScaler = postPostScaler % POSTSCALER2;
        if (postPostScaler == 0) {
            increaseClock();
            turnOffLeds();
            updateShiftRegisters();
            updateView();
        }
    }
    
    int_restore_registers
    T0IF = 0; // clear interrupt flag
}

/**
 * Main routine
 */
void main(void) {
    initPorts();
    initTimer0Interrupt();
    postScaler = 0;
    postPostScaler = 0;
    
    // initial time
    state_minutes = 0;
    state_hours = 0;

    // global interrupt enable
    GIE = 1;
    
    while(1) {}
}

/**
 * Initialise PIC16F690 general purpose I/O ports.
 */
void initPorts(void) {
    TRISC.0 = 0; // DATA
    TRISC.1 = 0; // CLOCK
    TRISC.2 = 0; // STROBE
    TRISC.4 = 1; // BTN(min)
    TRISC.5 = 1; // BTN(h)
}

/**
 * Initialise timer0 with interrupts
 */
void initTimer0Interrupt(void) {
    /* 
        xxxx.0.xxx  assign prescaler to timer0 module
        xxxx.x.111  prescaling 1:256
    */
    OPTION = 0b00000111;

    // set timer value
    TMR0 = TIMERVALUE;

    // enable timer0 overflow interrupt
    T0IE = 1;
}

/**
 * Helper function for shiftOut.
 */
void shiftOutSingle(int b) {
    DATA_PORT = b;
    CLOCK_PORT = 1;
    nop();
    CLOCK_PORT = 0;
}

/**
 * Shifts out a byte of data one bit at a time. Starts from the most significant bit. 
 * Each bit is written in turn to a DATA_PORT, after which a CLOCK_PORT is pulsed
 * to indicate that the bit is available.
 */
void shiftOut(char val) {
    shiftOutSingle(val.7);
    shiftOutSingle(val.6);
    shiftOutSingle(val.5);
    shiftOutSingle(val.4);
    shiftOutSingle(val.3);
    shiftOutSingle(val.2);
    shiftOutSingle(val.1);
    shiftOutSingle(val.0);
    
    // NOT COMPILABLE
    /*for (i = 7; i <= 0; i--)  {
        mask = 1 << i;
        DATA_PORT = val & mask;
        
        CLOCK_PORT = 1;
        nop();
        CLOCK_PORT = 0;      
    }*/
}

/**
 * Update shift register values
 */
void updateShiftRegisters(void) {
    // HOURS
    switch (state_hours) {
        case 1:
            ONE;
            break;
        case 2:
            TWO;
            break;
        case 3:
            THREE;
            break;
        case 4:
            FOUR;
            break;
        case 5:
            HFIVE;
            break;
        case 6:
            SIX;
            break;
        case 7:
            SEVEN;
            break;
        case 8:
            EIGHT;
            break;
        case 9:
            NINE;
            break;
        case 10:
            HTEN;
            break;
        case 11:
            ELEVEN;
            break;
        case 0:
            TWELVE;
            // Eventual time adjustments here
            break;
        default:
            PEW0;
    }
    
    // MINUTES
    switch (state_minutes) {
        case 0:
            OCLOCK;
            break;
        case 1:
            MFIVE;
            MINUTES;
            PAST;
            break;
        case 2:
            MTEN;
            MINUTES;
            PAST;
            break;
        case 3:
            QUARTER;
            PAST;
            break;
        case 4:
            TWENTY;
            MINUTES;
            PAST;
            break;
        case 5:
            TWENTY;
            MFIVE;
            MINUTES;
            PAST;
            break;
        case 6:
            HALF;
            PAST;
            break;
        case 7:
            TWENTY;
            MFIVE;
            MINUTES;
            TO;
            break;
        case 8:
            TWENTY;
            MINUTES;
            TO;
            break;
        case 9:
            QUARTER;
            TO;
            break;
        case 10:
            MTEN;
            MINUTES;
            TO;
            break;
        case 11:
            MFIVE;
            MINUTES;
            TO;
            break;
    }
}

/**
 * Update clock face to show new time.
 */
void updateView(void) {
    shiftOut((char) VSR2);
    shiftOut((char) VSR1);
    shiftOut((char) VSR0);
    
    STROBE_PORT = 1;
    nop2();
    STROBE_PORT = 0;
}

/**
 * Power off all LEDs.
 */
void turnOffLeds(void) {
    VSR0 = 0;
    VSR1 = 0;
    VSR2 = 0;
    updateView();
}

/**
 * Increase clock state by one.
 */
void increaseClock(void) {
    int unsigned temp = 0;
    state_minutes += 1;
    temp = state_minutes % 12;
    if (temp == 0) {
        state_hours += 1;
        state_hours = state_hours % 12;
    }
    state_minutes = temp;
}

/**
 * Increase clock state by one.
 */
void increaseClockByHour(void) {
    state_hours += 1;
    state_hours = state_hours % 12;
}

/*
 *  HARDWARE
 *  --------
 *
 *  PicKit PIC16F690
 *  20-Pin Flash-Based, 8-Bit CMOS Microcontrollers with nanoWatt Technology
 *  
 *             _____________  ____________    
 *            |             \/            | 
 *      +5V---|Vdd        16F690       Vss|---GND
 *            |RA5               RA0/(PGD)|
 *            |RA4/AN3   AN1/REF/RA1/(PGC)|
 *            |RA3/!MCLR/(Vpp) RA2/AN2/INT|
 *  BTN(h) -<-|RC5/CCP                 RC0|->- DATA
 *            |RC4                     RC1|->- CLOCK
 *            |RC3                     RC2|->- STROBE
 *            |RC6                     RB4|->- BTN(min)
 *            |RC7                  RB5/Rx|
 *            |RB7/Tx                  RB6|
 *            |___________________________|
 *  
 * 
 *  CD4094BE
 *  8-Stage Shift-AND-Store Bus Register
 * 
 *             ____________  ____________  
 *            |            \/           | 
 *     RC2 ->-|STROBE   CD4094BE     Vdd|---+5V
 *     RC0 ->-|DATA        OUTPUT ENABLE|---+5V
 *     RC1 ->-|CLOCK                  Q5|->- 5B
 *      1B -<-|Q1                     Q6|->- 6B
 *      2B -<-|Q2                     Q7|->- 7B
 *      3B -<-|Q3                     Q8|
 *      4B -<-|Q4                    Q's|
 *      GND---|Vss                    Qs|->- DATA
 *            |_________________________|
 *  
 * 
 *  ULN2003A
 *  High-Voltage, High-Current Darlington Transistor Arrays
 * 
 *             ________  _________  
 *            |        \/        | 
 *      Q1 ->-|1B   ULN2003A   1C|->- LED0
 *      Q2 ->-|2B              2C|->- LED1
 *      Q3 ->-|3B              3C|->- LED2
 *      Q4 ->-|4B              4C|->- LED3
 *      Q5 ->-|5B              5C|->- LED4
 *      Q6 ->-|6B              6C|->- LED5
 *      Q7 ->-|7B              7C|->- LED6
 *            |E              COM|
 *            |__________________|
 */