Say hello to my little friend!

Now we have everything we need to know to start building our project. Let's start by writing the code:

#include <NewPing.h> 
  
int ledPin=10; 
int trigPin=8; 
int echoPin=9; 
 
NewPing sonar(trigPin, echoPin); 
  
 
void setup() { 
 
pinMode(ledPin,OUTPUT); 
 
} 
 
void loop() { 
  delay(50); 
  int dist = sonar.ping_cm(); 
  if (dist < 15) 
digitalWrite(ledPin,HIGH); 
    else 
         digitalWrite(ledPin,LOW); 
          
} 

Like before, we start by storing the pin numbers in variables, so that it doesn't become confusing, and then initialize our LED pins for output. The code consists of a simple if statement that checks if an object is closer than 15cm, and if it is, lights up our LED's. If not, it turns our LED's off.

Now that our code is ready, let's build our project!

We begin by cutting out a head shape out of cardboard:

We...