Recently I've worked on a IR radar system by utilizing the sharp GP2D12 sensor. The sensor generates a voltage proportional to the distance to the measured object. I've used a PIC 18F458 microcontroller to measure that voltage and draw a radar screen on the 128x64 graphical LCD display.

The microcontroller also generates the pwm signals for driving the RC servo motor. The servo motor turns the IR sensor for scanning the environment.

Step 1: Videoclip

here is a videoclip of the system while working.

Step 2: Circuit Schematic

here is the circuit schematic and the proteus simulation file

a more detailed version of the circuit schematic is in the zip file.

the DSN file is also full detail. it also simulates the circuit, all you need to do is to download the proteus demo version from www.labcenter.co.uk

Step 3: Source Code

#include <18F458.h>
#device ADC=8
#fuses HS,NOWDT,NOPROTECT,NOLVP
#use delay(clock=8000000)
#use rs232(baud=9600, xmit=PIN_C6, rcv=PIN_C7)

#define GLCD_WIDTH 128

#define GLCD_E PIN_E0 // Enable
#define GLCD_DI PIN_B5

#define GLCD_CS1 PIN_A1 // Chip Selection 1
#define GLCD_CS2 PIN_B0

#define SERVO PIN_A3

#include <HDM64GS12.c>
#include <graphics.c>
#include <math.h>

char message[] = "EndtaS RaDaR";
float theta = 0, ytheta;

void main() {

int1 enbas;
int mesafe;
int car1, sayac, a;
int16 servopos;

setup_adc_ports(RA0_ANALOG);
setup_adc(ADC_CLOCK_INTERNAL);
set_adc_channel(0);
enbas:
glcd_init(ON);

glcd_fillScreen(OFF);

glcd_text57(30, 0, message, 1, 1);

glcd_circle(29, 37, 26, 0, 1) ;
glcd_pixel( 29 , 37 , ON);
theta = 7.85;
servopos = 550;
printf("Scan_START\r\n");
while(TRUE){

mesafe = read_adc();
//printf("th: %f -> %u \r\n\n",theta, mesafe);

ytheta = theta;
sayac = 1;
if ( enbas == TRUE ){
sayac = 50;
}
for ( a=0 ; a<sayac ; a++){
output_high(servo);
delay_us(servopos);
output_low(servo);
delay_us( 20000 - servopos );
}
if ( enbas == TRUE ) {
glcd_circle(29, 37, 25, 1, 0);
glcd_pixel( 29 , 37 , ON);
printf("Scan_START\r\n");
delay_ms(300);
}

if (ytheta >= 4.51 ) {
ytheta -=.02;
servopos += 12;
enbas = FALSE;
}
else {
//glcd_circle(29, 37, 25, 1, 0) ;
ytheta = 7.85;
servopos = 550;
//glcd_pixel( 29 , 37 , ON);
enbas = TRUE;
printf("Scan_COMPLETE\r\n");
}

//glcd_pixel( 28+(int)(car1*sin(-theta)+.5), 38-(int)(car1*cos(theta)+.5), OFF);

//glcd_pixel( 28+(int)(car1*sin(-theta-1)+.5), 38-(int)(car1*cos(theta-1)+.5), OFF);

theta = ytheta;

car1 = mesafe / 8;
glcd_pixel( 28+(int)(car1*sin(-theta)+.5), 38-(int)(car1*cos(theta)+.5), ON);
//delay_ms(10);
}
}