Hi,
I'm trying to finish my first Arduino UNO project; an ultrasonic obstacle avoidance rover. I'm having difficulties getting my sensor to operate simultaneously with the servo it is mounted on. The idea is to create a 180-degree scan for nearby objects to navigate a path. Is there a way to make my sensor take readings whilst the servo is rotating the head? Please have a read of my code so far and suggest how I could make this work. The robot is powered by 9v, two DC motors, an Adafruit motor shield, SR04 sensor and a standard 9g micro servo - p.s I only just started learning Arduino two days ago 
Please help me! :
#include <NewPing.h>
#include <Servo.h>
#include <AFMotor.h> //
#define trigPin A4
#define echoPin A5
AF_DCMotor motor1(1,MOTOR12_64KHZ); // set up motors.
AF_DCMotor motor2(4, MOTOR12_64KHZ);
Servo myservo; // create servo object to control a servo
int pos = 0; // this sets up variables for use in the sketch (code)
void setup() {
Serial.begin(9600); // begin serial communication
Serial.println("Motor test!");
pinMode(trigPin, OUTPUT);// set the trig pin to output (Send sound waves)
pinMode(echoPin, INPUT);// set the echo pin to input (recieve sound waves)
motor1.setSpeed(105); //set the speed of the motors, between 0-255
motor2.setSpeed (105);
myservo.attach(9); // attaches the servo on pin 9 to the servo object
myservo.write(90); // tells the servo to position at 90-degrees ie. facing forward.
}
void loop() {
long duration, distance; // start the scan
digitalWrite(trigPin, LOW);
delayMicroseconds(2); //
digitalWrite(trigPin, HIGH);
delayMicroseconds(10); //
digitalWrite(trigPin, LOW);
duration = pulseIn(echoPin, HIGH);
distance = (duration/2) / 30;//
if (distance < 25)/*if there's an obstacle 25 centimers, ahead, do the following: */ {
Serial.println ("Close Obstacle detected!" );
Serial.println ("Obstacle Details:");
Serial.print ("Distance From Robot is " );
Serial.print ( distance);
Serial.print ( " CM!");// print out the distance in centimeters.
Serial.println (" The obstacle is declared a threat due to close distance. ");
Serial.println (" Turning !");
motor1.run(FORWARD); // Turn as long as there's an obstacle ahead.
motor2.run (BACKWARD);
if (distance < 10)
motor1.run(BACKWARD);
motor2.run(BACKWARD);
delay(400); // run motors this way for 400ms
}
else {
Serial.println ("No obstacle detected. going forward");
delay (15);
motor1.run(FORWARD); //if there's no obstacle ahead, Go Forward!
motor2.run(FORWARD);
}
for (pos = 0; pos <= 180; pos += 1) { // goes from 0 degrees to 180 degrees
// in steps of 1 degree
myservo.write(pos); // tell servo to go to position in variable 'pos'
delay(15); // waits 15ms for the servo to reach the position
}
for (pos = 180; pos >= 0; pos -= 1) { // goes from 180 degrees to 0 degrees
myservo.write(pos); // tell servo to go to position in variable 'pos'
delay(15); // waits 15ms for the servo to reach the position
}
}
