The spirit of Hanukkah, the Festival of Lights, is shared by all people who love freedom.
—Norma Simon

Late December marks the holiday season for much of the world. Seasonal songs, tree decorating and gift-giving seem to dominate the landscape. Everyone at the company Holiday party is decked out in their favorite Ugly Christmas Sweater, laughing in their red and green as Santa's booming Ho, Ho, Ho drowns out every other sound.

Here's an opportunity for all the Jewish folks to light up the holidays in their own style. Add NeoPixels and a Gemma M0 to your handmade Menorah sweater, and be the life of the party. Touch the center shamash candle to light all eight Hanukkah candles, and celebrate each magical night with your family and friends.

This is an easy beginner project - just perfect for crafting together with your kids this Holiday season. There's no soldering or sewing required. Use our drag-and-drop code, or dig in and learn to create your own colors and sequences. Make one for everyone in your family and pose for the perfect Hanukkah family photo.

Mazel Tov!

Materials Needed

You'll Also Need

• A sweater with a fairly tight knit
• Heat Transfer Vinyl in your favorite color
• Fusible interfacing
• Sticky-back velcro dots
• Fabric or embellishment glue

Tools

• Soldering iron & solder (optional)
• Vinyl cutting machine (like a Cricut or Silhouette) OR a good sharp utility knife
• Iron
• Screwdriver
• Awl

We'll wire the NeoPixel strand to the Gemma as shown: the red wire goes to VOUT, the IN end of the middle wire to D1, and the remaining wire goes to G.

We could connect the power and ground wires from either end of our NeoPixel strand, but the middle data wire must be connected to the IN end or the lights won't work. It can be a bit tricky to tell which end is IN and which is OUT on these pixels, but if you get your magnifying glass out and look really closely, you'll see a tiny red or green dot on each pixel. The dot isn't perfectly round - it has a pointy end which points in the direction of data flow. So be sure to connect to the end with the tiny arrows pointing away.

 

MakeCode is Microsoft's ritzy drag-and-drop code editor. It makes it easy to get up and running with the Gemma M0. 

Find the Gemma M0 code editor at maker.makecode.com

Here's my completed project. This code will light the center shamash pixel in red, then light the 8 individual candle pixels sequentially in gold each time the D0 capacitive touch pad is touched.

Click the Download link at the bottom, plug your Gemma M0 into your computer, click or double-click the reset button and drag the file onto the resulting GEMMABOOT drive. 

Or, follow along below to create your own project from scratch.

Code It Yourself

Head to https://maker.makecode.com and select New Project. Choose the Gemma M0 board. Give your project a name. I called mine Hanukkah Sweater.

On Start Block

First we'll write the code that runs once, when the Gemma powers up. This is where we set up our variables and set up our pixel strip.

Note: NeoPixels are also called WS2812 pixels, and DotStars are also called APA102 -- make sure you've got the right ones selected.

Next, drag an instance of strip set brightnessinto your on start loop.  Set the brightness to whatever you'd like.  I want them as bright as possible, so I chose 255.

FOREVER Loop

Next we'll set up the main body of the code, in our FOREVER loop. Anything in this loop will run over and over, forever. 

We can keep this part really simple. 

INPUT Loop

Now, all we need to do is set up our input. We want each pixel to light up in sequence whenever we touch our capacitive touch pad (D0). 

Testing It Out

It's working! Each candle turns sequentially gold when we click the pad. 

However, it's not quite perfect. The shamash candle is at pixel 4, and this code overwrites the red color as it counts up. We can fix this by setting the pixel back to red each time the button is clicked.

Adding Logic

We can go with this code, or we can get fancy and add one more step. We can use logic to get our day variable to "skip" pixel 4, for a much smoother user experience.

Resetting 

This works great! We can stop here, or add one more fancy feature: we can code a reset at the end, so if we accidentally go too far (or just want to be able to play with the sweater indefinitely) the code will start over at the beginning.

Try it out on your emulator. Once you're happy with the way it works, click the DOWNLOAD button to program your Gemma. 

Plug your Gemma M0 into your computer using a USB cable. Click the tiny Reset button in the middle of the board and the onboard pixel will turn green. When the lights turn green, a new drive will appear on your computer called GEMMABOOT.

In MakeCode, click the Download button to download your code to a file. Drag this file onto the GEMMABOOT drive.  It may also ask you if you'd like to pair the board to your computer.  Feel free to follow the directions to do this (you may need to update the bootloader), or you can skip it and simply drag the downloaded file onto GEMMABOOT.  Pairing the board makes it easier if you want to download and test again and again, since it will load the code automatically without you needing to drag the file each time.

Troubleshooting

If it's not working, here are a few things to check:

• Did you set your strip to pin D1 in the on start block? I seem to miss this step sometimes.
• Did you call the onboard pixel instead of the strip? These blocks are similar and easy to confuse. Make sure you're suing set strip pixel color and not set pixel color
• If you just can't make it work, try starting with the completed code linked at the top of the page and working backwards

If your GEMMABOOT drive is not appearing, check out this guide for more troubleshooting tips.

Make the Menorah

I looked and looked (and looked!) for a silly Hanukkah sweater to use in this project. I saw around 1,000 ugly Christmas sweaters but not a single Hanukkah sweater could be found, silly or otherwise.

This seems somehow unfair. But, all the more reason to make our own! 

Find a sweater that's got a fairly tight weave and fits somewhat loosely. Blue is good.

Heat Transfer Vinyl

Download the menorah graphic linked below.

If you're cutting by hand, you can print out menorah_print.pdf to use as a pattern. Feel free to size it up or down to fit your sweater. On me, 8" wide is just the right size.

If you're using a cutting machine, upload menorah.svg to your cutting machine's software program. Resize it to your preferred size and get ready to cut.

Cutting with a Vinyl Cutting Machine

Cutting by Hand

If you're cutting by hand, it can be tricky to cut through only the back two layers. It's possible if you're gentle with the knife, but it may be easier to cut through all 3 layers and then put another layer of paper or acetate over the top when you're ready to iron.

Placement

Interfacing

Most sweaters are fairly stretchy. Heat Transfer Vinyl is decidedly not stretchy. This could become a problem - if the sweater stretches too much, your menorah will rip.

The easiest solution is to add a patch of fusible interfacing to the inside of the sweater to take the stretchiness out of the area where we'll fix the vinyl. Fusible interfacing is sold by the yard at fabric stores, or you can find it online. It comes in a variety of weights. Its purpose is to stabilize an area of fabric and keep it from stretching, so it's perfect for applications like this.

I'm using a medium weight interfacing since I have a medium weight sweater.

Attach the Electronics

Use the on/off switch on the face of the Gemma M0 to power your sweater on at dusk. Touch your shamash to light each candle. 

When you're done wearing your sweater, unscrew the bolt and unplug the connector before washing. Let the sweater and electronics dry completely before powering them back up again.