/*
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