Introduction: LUMOS Nightlight

I am in a Youth and Technology class this semester, and one of our projects involves programming a LilyPad Arduino to create a toy or gadget of some sort and thinking about how libraries can use this technology to facilitate child or teen development and learning. I have never used Arduino before, and technology is a bit of a struggle for me, so I decided to go with something simple for this project. This is a simple round, Harry Potter-themed nightlight, with a light sensor under the flap on the back. When the sensor senses little to no light, as it should under the flap, the lights will come on around the word LUMOS.

Step 1: Gather Materials

For this project, you will need:

and Battery

Light Sensor

White LED lights

Conductive Thread


Mini UBS cord

Dark blue felt

Letters spelling out “LUMOS” (style of choice)


Washable marker

Step 2: Stitching Circuits

1. Plan and sketch the layout of the panel. Show where the stitching for the conductive thread will run, making sure not to cross stitch paths, as this will short out your circuit.

2. Cut out two 12-inch diameter circles.

3. On the back side of the first circle, place your motherboard on the bottom center, with the A5 petal pointing towards the top of the circle. Place the light sensor above the motherboard, with the S petal pointing up.

a. Note: Light sensor is placed on the back of the circle so that when back flap is closed, no light is sensed and the LED lights will come on.

4. Begin stitching circuits. Start by connecting the + petal on the light sensor to the A5 petal on the motherboard. Make several passes through the + sensor and make a neat line of stitches down to the A5. Be sure not to pass the stiches through the fabric entirely; you do not want your stitches to appear on the front of the circle of felt.

a. Note: Make sure the switch on the motherboard is turned to OFF while sewing your circuits. This will ensure that there is no power running from the battery while sewing. If the power is not turned off, incidental touching of threads from the – and + petals while sewing may result in a small spark and some smoke. While this spark cannot start a fire, the smoke smells unpleasant and your conductive thread may not work properly afterward.

b. Note: for those used to conventional sewing, note that conductive thread does not run as smoothly as regular thread. You may need to pull the thread through the fabric more slowly than usual.

5. Next, connect the S petal on the light sensor to the A2 petal on the motherboard, using technique from step

6. Lay out letters and LED lights on the front of the circle in the manner you want them to appear in the finished product. DO NOT yet glue letters: this may interfere with your stitching at this point. Mark on the back of the circle with washable marker where your LEDs will be placed to guide you stitching.

7. Using a long piece of thread, begin by stitching a line connecting the – petal on the light sensor to the – petal on the motherboard, then continue this path so that it connects to all of the – petals on the LED lights. Make sure you have enough length of thread on your needle to complete this circuit.

8. Using another long piece of thread, connect the 10 petal on the motherboard to the + petals on the LEDs. Once you have completed this step, the LEDs should be functional. Push the switch on the motherboard to ON and cover the light sensor to test.

Step 3: Finish Crafting

1. Glue your letters onto the front of one circle. Let dry.

2. Lay second circle on top of the back of the first circle. Fold the bottom up just far enough for the light sensor and motherboard to be easily accessed. Make a mark where the fold starts. Line the circle with glue from mark to mark.

3. If you do not like the look of the LEDs on the front of your nightlight, you may find a thin fabric that the light will shine through to cover. I suggest white or yellow for the color. You might cut this fabric into small circles or stars.

Step 4: The Code

For the Code:

1. Attach the battery from your LilyPad kit to the board. Next attach the FTDI board to the LilyPad, and using the mini USB, plug the LilyPad into your computer.

2. Using the Arduino software, input your code and upload it to the LilyPad motherboard. Test it out!

Note: all writing in grey, following // is a note; this will not have any affect on your code.

Credit given to crheld, whose code I modified to do this project. Her project and code can be found at