Sharp GP2-programming distance sensor

[fantabulous68]

sharp gp2

This is for the PIC 18F1320 BUT i want to modify this code to suit the PIC16f690. I am trying but not sure about a few things. I attached a word document with the relevent datasheets from the 18F and 16F.

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!
		}

	}
}

My code to suit pic 16f690:

	[COLOR="Red"]TRISA = 0b10000010;[/COLOR] 	// RA7 high imp, RA3 is serial out,
				// RA1 is ADC input measuring VR1

Question1:The 16f690 doesnt have a RA7. What does makin the pin a high impedance mean? Im assuming imp is impedance. I know TRIS sets pins as inputs and outputs.

*********************************************************
Im sure this part is rightEasy part
//18F

PORTB = 0;
INTCON2 = 0;            // PORTB pullups ON
TRISB = 0b00000000; 	// PORTB not used

//16F

PORTB = 0;          
WPUB = 1;
RABPU = 0;

*********************************************************

//18F

[COLOR="Indigo"]ADCON0 = 0b00000101;	// ADC ON, RA1 is ADC input
ADCON1 = 0b01111101;	// AN1 is ADC input
ADCON2 = 0b10100010;	// right justify, 8Tad, 32Tosc[/COLOR]

//16F

ADCON0 = 0b10000101;	// bit 7 right justify,analogue channel select bits bits5-2  0001=AN1,ADC ON, RA1 is ADC input
ADCON1 = 0b00100000;	//bits6-4  fosc/32

Question2:
I dont know how to set 8Tad on the 16f690. Could someone please tell me how to do that?

Question3:
Does analogue channel select bits bits5-2 0001=AN1 mean that AN1 is ADC input?


Im going to collect the sharp GP2 today