Guardian Angel

Today we’re making an angel with 8 LEDs that light up when you get close to it. That way, you know when your guardian angel is with you.

angel_hero

You’ll need:

  • 8 blue and white LEDs
  • 1 Ping sensor
  • Arduino UNO
  • Breadboard + wires
  • Angel model
  • Paint
  • Blue and white feathers
  • Chenille wires
  • Conductive tape

angel_intro

1) Making the Angel
Apply a first layer of white paint on your cardboard model. Then, mix blue and white paint (don’t blend them completely to get a nice gradient) and apply the blue paint to the body only. Let it dry before making the halo out of silver chenille wire. See below:

angel_one

On the outside of the wings, stick various shades of blue feathers, keeping the darker ones underneath. To stick the feathers, apply the glue to the wing, put the feather on top and push it down gently with a paint brush. On the inside of the wings, stick white feathers.

angel_two

2) The LEDs
Prepare the LEDs on your breadboard first, alternating white and variations of blue.
Check that they work properly through one pin (make sure this pin is PWM, marked with a ~ on the Arduino board). Using analogWrite to get the fading effect.

I then added a Ping sensor to my circuit to control the fading effect.
angel_leds

For the ping sensor, since I had a 4-pin one (as opposed to the 3-pin one that is demo’ed on the Arduino website), I used this code sample, and just added the code for my LEDs in the loop function:

//ledPin is 6
//if there's an obstacle detected at less than 25cm  
if(cm <= 25) {
//brightness is an int
    brightness = map(cm, 0, 25, 0, 255);
//turn the light on brighter, the closer you get
    analogWrite(ledPin, (255-brightness));
  } else {
//turn the LEDs off
    analogWrite(ledPin,0); 
  }
  
  delay(50);

3) Being close to your angel
angel_three
Next, mark the spacing of your LEDs down on a piece of tape, put it on the body of the angel and pierce holes accordingly, to let the LEDs through easily.

angel_four
Layout the inside of your angel with conductive tape. Transfer the LEDs onto your model. make sure they make good contact with the conductive tape. Fix alligator clips to the end of your tape and to your Arduino board and you’re done!

We’re already a third of the way through! 16 more activities to come…

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