We'll build out the circuit starting with the NeoPixels. These will plug into the JST port on the Propmaker FeatherWing which can drive them with more power than a bare microcontroller on its own.

A pair of toggle switches will connect the Propmaker for powering the project on and off via the Enable pin, and for switching song/color modes.

To drive the four speakers we'll connect one to the amp built into the Propmaker and then add three 2.5W class D amps for the remaining speakers.

We'll plug the Feather and Propmaker into a quad FeatherWing kit which gives us plenty of prototyping area to connect the amps and the trigger buttons. Adding Feather terminal headers make it easy to connect the buttons.

Here's a Fritzing diagram of the complete circuit:


We'll create a single circuit of all the NeoPixel strands, rings, and jewel so that they share a single data line, ground, and power.

First, solder together the four quarter segments into a single ring. When doing so, be sure to solder all of the power and ground pads, and three of the four Data In/Data Out pairs.

On the un-soldered Data In segment, solder a JST wiring interconnect cable so that the ring can be connected to the rest of the NeoPixels -- this will be the last set of NeoPixels so it doesn't need an out cable.

And More NeoPixels

Solder a pair of in/out interconnect cables to each ring, jewel, and strand so they may all be joined.

It's important to be consistent with polarity of interconnects so all of the Data In sides can only be connected with Data Out sides.

Connect the Strands

I decided to wire the two VU meter strips directly to each other, and use the interconnects at either end for connecting to the Propmaker FeatherWing and the rest of the circuit.

Plug them all together and they're ready for use!

You may choose to wire each segment directly to the next, which will work just fine. Interconnects are a bit of extra effort, but give you added freedom during integration with your prop blaster parts.

Quad Board

Solder female headers into the top two positions of the Quad board.

Solder male headers to the underside of the Feather and the Propmaker so they can be attached to the Quad.

Then, solder the terminal blocks to the bottom quad area.

Add Amps

Use three sections of male header pin rows to solder the three amps to the prototyping area as shown, pushing the long ends of the pins down into the board so they can be used as posts for soldering the wires.

We'll wire the circuit connections as they're shown in the Frizing diagram, except we'll do it underneath the board.

Solder a set of wires from the Quad board GND to the GND posts of the two bottom amps as shown in the first wiring picture here.

This is followed by running a circuit from the +V rail to the appropriate posts.

Then, run the A0 pin to the A+ (audio in) pin on both bottom amps and the A1 pin to the A+ of the top amp.

Connect Speakers & Switches

Connect two of the small speakers and the large front speaker to their respective amps as shown using the terminal blocks.

The third small speaker will connect to the speaker output on the Propmaker. Do this by grafting in a Molex "Pico-Blade" connector.

You'll use the Feather terminal headers to connect the trigger buttons to ground, A5 and A6.

The toggle switches are connected to the En & GND pins on the Propmaker wing and the SW & GND pins, also on the Propmaker. You can solder these directly or add a couple of 0.1" terminal blocks first.

NeoPixels, USB, & Battery Power

You can now plug in the LiPoly battery as well as the USB panel mount to extend the Feather's USB port to make it accessible from the exterior of the prop. The USB will be used both for programming the Feather as well as charging the battery.

Plug the NeoPixel mega strand into the JST socket on the Propmaker FeatherWing and the blaster is ready to go!

This guide was first published on Jul 08, 2020. It was last updated on Jun 10, 2020.

This page (Build the Blaster Circuit) was last updated on Jun 30, 2020.

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