Ultrasonic to servo motor using arduino

[veevieneane1]

it does not move when detected. although it moved back then

[jim-p]

Have you written code and uploaded it to Uno?

[veevieneane1]

yes

SERVO VIA ULTRASONIC
#include <Servo.h>

// constants won't change
const int TRIG_PIN  = 9;  // Arduino pin connected to Ultrasonic Sensor's TRIG pin
const int ECHO_PIN  = 10;  // Arduino pin connected to Ultrasonic Sensor's ECHO pin
const int SERVO_PIN = 5; // Arduino pin connected to Servo Motor's pin
const int DISTANCE_THRESHOLD = 10; // centimeters

Servo servo; // create servo object to control a servo

// variables will change:
float duration_us, distance_cm;

void setup() {
  Serial.begin (9600);       // initialize serial port
  pinMode(TRIG_PIN, OUTPUT); // set arduino pin to output mode
  pinMode(ECHO_PIN, INPUT);  // set arduino pin to input mode
  pinMode(13, OUTPUT);  // set arduino pin to input mode
  servo.attach(SERVO_PIN);   // attaches the servo on pin 5 to the servo object
  servo.write(0);
}

void loop() {
  // generate 10-microsecond pulse to TRIG pin
  digitalWrite(TRIG_PIN, HIGH);
  digitalWrite(13, HIGH);
  delayMicroseconds(10);
  digitalWrite(TRIG_PIN, LOW);

  // measure duration of pulse from ECHO pin
  duration_us = pulseIn(ECHO_PIN, HIGH);
  // calculate the distance
  distance_cm = 0.017 * duration_us;

  if (distance_cm < DISTANCE_THRESHOLD)
    servo.write(180); // rotate servo motor to 90 degree
  else
    servo.write(0);  // rotate servo motor to 0 degree

  // print the value to Serial Monitor
  Serial.print("distance: ");
  Serial.print(distance_cm);
  Serial.println(" cm");

  delay(500);
}

[jim-p]

Try this:

//SERVO VIA ULTRASONIC
#include <Servo.h>

// constants won't change
const int TRIG_PIN  = 9;  // Arduino pin connected to Ultrasonic Sensor's TRIG pin
const int ECHO_PIN  = 10;  // Arduino pin connected to Ultrasonic Sensor's ECHO pin
const int SERVO_PIN = 5; // Arduino pin connected to Servo Motor's pin
const int DISTANCE_THRESHOLD = 10; // centimeters

Servo servo; // create servo object to control a servo

// variables will change:
unsigned long duration_us;
float distance_cm;

void setup() {
  Serial.begin (9600);       // initialize serial port
  pinMode(TRIG_PIN, OUTPUT); // set arduino pin to output mode
  digitalWrite(TRIG_PIN, LOW); // set LOW
  pinMode(ECHO_PIN, INPUT);  // set arduino pin to input mode
  //pinMode(13, OUTPUT);  // set arduino pin to output
  servo.attach(SERVO_PIN);   // attaches the servo on pin 5 to the servo object
  servo.write(0);
}

void loop() {
  // generate 10-microsecond pulse to TRIG pin
  digitalWrite(TRIG_PIN, HIGH);
  //digitalWrite(13, HIGH);
  delayMicroseconds(10);
  digitalWrite(TRIG_PIN, LOW);

  // measure duration of pulse from ECHO pin
  duration_us = pulseIn(ECHO_PIN, HIGH);
  // calculate the distance
  distance_cm = 0.0172 * (float) duration_us;

  //***************************************************************
  // if distance is less then DISTANCE_THRESHOLD move to 90 degrees
  // else set to 0 degrees
  //***************************************************************

  if (distance_cm < DISTANCE_THRESHOLD)
    servo.write(90); // rotate servo motor to 90 degree
  else
    servo.write(0);  // rotate servo motor to 0 degree

  // print the value to Serial Monitor
  Serial.print("distance: ");
  Serial.print(distance_cm);
  Serial.println(" cm");

  delay(500);
}