/*

Partial source listing for Linear Actuator Elevation Control and Display

Jim White, WD0E. February, 2001

*/

bit last_pulse_state = 0;          //save of last pulse high or low state

int up = 0;                        //moving up = 1 or down = 0

char outdata[16];                  //buffer for output to LDC

eeprom int zero_ele;               //counts of pulses at zero elevation.

eeprom int ninty_ele;              //counts at 90 elevation

eeprom int posit;                  //position in pulse transitions.

int degrees = 0;                   //degrees of elevation

char c;                            //input character from UART

eeprom float mult;                 //counts per degree after calibration

char tmpstring[5];                 //diagnostic for testing

void do_math(void)              //calculate the counts, then the degrees and display

{

    if (up) posit++;

    else posit--;

    degrees = ((float)posit-(float)zero_ele) / mult;

    sprintf(outdata,"C=%4d Deg=%d ",posit,degrees);

    lcd_gotoxy(0,1);

    lcd_puts(outdata);

    ftoa(mult,10,tmpstring);

    printf("DIAG: posit = %d, mult = %s, degrees %d\n\r",posit,tmpstring,degrees);

}

void main(void)

{

    printf("\n\rElevation Control starting\n\r");

    while (1) {

        //Loop till power comes on up or down

        while(PINA.1 == 0 && PINA.2 == 0) {          //No power

        lcd_gotoxy(0,0);

        lcd_putsf("ELEVATION OFF ");

        //last position

        sprintf(outdata,"C=%4d Deg=%2d",posit,degrees);

        lcd_gotoxy(0,1);

        lcd_puts(outdata);

        //if a char in the serial buffer then user wants

        if (rx_counter > 0) {

            c = getchar(); // to start calibration

            switch (c) {

                case '0' :

                    posit = 100;

                    zero_ele = posit;

                    printf("\n\rZero location saved.");

                    printf("\n\rMove elevation to ninty degrees and hit 9 ");

                break;

                case '9' :

                    ninty_ele = posit;

                    mult = ((float)ninty_ele - (float)zero_ele)/90;

                    ftoa(mult,10,tmpstring);

                    printf("\n\rmult = %s",tmpstring);

                    printf("\n\r90 degree elevation saved.");

                    printf("\n\rCalibration complete");

                break;

                default :

                    printf("\n\rStarting calibration.");

                    printf("\n\rMove elevation to zero degrees and hit 0 ");

                break;

            } //switch

        } //if character in buffer

    } //while no power applied

    //Power is applied

    lcd_gotoxy(0,0);                          //See if we are going up or down

    if(PINA.1) {

        lcd_putsf("ELEVATION UP ");           //And show it

        printf("Elevation up posit = %d\n\r",posit);

        up = 1;

    }

    else {

        lcd_putsf("ELEVATION DOWN");

        printf("Elevation down posit = %d\n\r", posit);

        up = 0;

    }

//Now count pulses

    while(PINA.0 == last_pulse_state) {};          //loop till pulse state changes

    last_pulse_state = PINA.0;                     //save this as last state

    printf("pulse\n\r");

    do_math();                                     //go calc the degrees and display

    } //while 1

} //main