Electronics Assembly

To keep this project as magical as possible, we want to hide all the wires inside or behind the dragon. This calls for a little extra wire. I like this 26awg silicone stranded wire. It doesn't break and it's really easy to work with. I keep a whole drawer full of the stuff in lots of various colors.

It will make your life a bit easier to use some JST connectors to connect the Circuit Playground to the lights inside the dragon. We'll solder the connectors on, then run longer wires to the two different LED strips. Then we can mount the dragon to the board and thread the connectors through a couple small holes we'll drill in the mounting board. 

Solder two female 3-pin connectors as shown:

  • 2 red (or right-side) wires to VOUT
  • 2 middle / green wires to A0 and A1
  • 2 blue (or left-side) wires to GND

Not all JST connectors are color coded, so if yours are just plain black, you'll want to double check to be sure the other end of the connectors are soldered the same way (i.e. not upside-down). When the connectors are plugged into the LED strips, you'll want to be sure VOUT goes to + and GND goes to - on the strips.

Find the IN end of the LED strand. It should have a male connector on it. Cut the connector off. 

Measure the distance from the head of your dragon to where you want to place the Circuit Playground Express, taking into account some extra wire length so the wires stay hidden inside the dragon. Add a few more inches to this for good measure. It's easy to bunch up extra wire inside the dragon or behind the mounting board, but hard to add more wire if it's too short, so be generous here. Cut a red, yellow, and black wire to length.

Solder your three long wires to each of the three wires on the LED. Solder red to the red-striped wire, yellow to the middle wire, and black to the remaining wire. 

Then, go to the other end of the three long wires and solder the connector back on in the same order.  Plug your connector in and make sure your strand lights up.

Now do the same thing with your NeoPixel strip. Solder red to +, yellow to IN and black to G, and add a male connector back on at the end of the extension wires.

Once you're sure the strip is working, it's helpful to seal up the end of the strip with your solder connections with hot glue. Just squirt a little inside the silicone casing.

This guide was first published on Apr 02, 2019. It was last updated on Apr 02, 2019. This page (Electronics Assembly) was last updated on Jan 05, 2020.