DC motor with ultrasonic sensor

Projects General Guidance
1

So I'm trying to make a device that when the ultrasonic sensor senses something less than 20 cm away, the motor activates. Here is my code:

const int trigPin = 9;
const int echoPin = 10;

const int motor = 7;

long duration;
int distance;

void setup() {
Serial.begin(9600);
pinMode(trigPin, OUTPUT);
pinMode(echoPin, INPUT);
pinMode(motor, OUTPUT);
}

void loop() {
digitalWrite(trigPin, LOW);
delayMicroseconds(2);

digitalWrite(trigPin, HIGH);
delayMicroseconds(10);
digitalWrite(trigPin, LOW);

duration = pulseIn(echoPin, HIGH);

distance = duration*0.034/2;

Serial.println(distance);

digitalWrite(motor, HIGH);
}

I'm now trying to wire the whole thign to my Arduino Uno, but I can't get it to work. Does anyone know a way I could wire this ONLY using wires and a breadboard? BTW the motor requires a tiny amount of voltage to run, so it runs when plugged into the Arduino.

2

Does the distance measurement work?

when the ultrasonic sensor senses something less than 20 cm away, the motor activates.

You need an [u]if-statement[/u].

BTW the motor requires a tiny amount of voltage to run, so it runs when plugged into the Arduino.

What's the current rating on the motor? The Arduino I/O pins are rated for 40mA (0.04A) "absolute maximum". Any more than that and you are over-stressing the Arduino. And, make sure to add a reverse diode across the motor to kill the high voltage [u]back-EMF[/u] when the motor shuts off.

3

if(distance < 20)
{
digitalWrite(motor, HIGH);
}
else
{
digitalWrite(motor, LOW);
}
}

I'm not sure what rating it is but the motor runs fine off a AAA battery. Also, I'm trying not to use anything besides wires, the arduino, the motor, and the sensor because I don't want to spend more money on it, as this is just a prototype, so is there any way to wire it just with wires?