void main()
{
// setup the [B]PIC 18F1320[/B]
OSCCON = 0x72; // internal osc, 8MHz
PORTA = 0;
[COLOR="Red"]TRISA = 0b10000010;[/COLOR] // RA7 high imp, RA3 is serial out,
// RA1 is ADC input measuring VR1
PORTB = 0;
INTCON2 = 0; // PORTB pullups ON
TRISB = 0b00000000; // PORTB not used
[COLOR="Indigo"] ADCON0 = 0b00000101; // ADC ON, RA1 is ADC input
ADCON1 = 0b01111101; // AN1 is ADC input
ADCON2 = 0b10100010; // right justify, [B][I]8Tad[/I][/B], 32Tosc[/COLOR]
T1CON = 0b00010001; // TMR1 is ON, 1:2 prescale, =1MHz
T3CON = 0b00010001; // TMR3 is ON, 1:2 prescale, =1MHz
// main loop here;
while(1)
{
// wait for 2 seconds, uses TMR1 free running at 1Mhz
while(!PIR1.TMR1IF); // wait for TMR1 overflow
PIR1.TMR1IF = 0; // clear overflow flag
LATA = 0; // all LEDs off
bres += 65536; // add 65536uS to bres value
if(bres >= 2000000) // if reached 2 seconds!
{
bres -= 2000000; // subtract 2 seconds, keep error
// flash Junebug LED1, RA0=1 RA6=0 RA7=hiimpedance
LATA.F0 = 1; // LED on
// read the ADC voltage RA1 (Sharp GP2 sensor)
ADCON0.F1 = 1; // set GO bit, start doing ADC
while(ADCON0.F1); // wait until ADC done
calc_distance(); // convert ADC value to distance
send_serial_message(); // send message back to PC!
}
}
}