Explore the board

Welcome to Jay-D's anatomy guide!

Whether you already assembled your Jay-D or not, this is going to be a helpful guide where you’ll learn a bit more about the soldered components, small connections, LED lights, and drivers.

We'll start with bigger components and cover smaller components later in the guide.

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Exploring the board

Starting with anything else but the PCB board itself would be wrong. Therefore, we present you the star of the night...

PCB stands for a printed circuit board. 
Basically, this fiberglass board has copper traces on it, some protective paint, and insulating material.  

Thanks to all the copper leads on the board, all the connected or soldered components can communicate with each other.

Without it, speakers wouldn’t be able to play the music that you remix, the display wouldn’t react after any input from the rotary encoders or slider potentiometers, and LED lights wouldn’t turn on.

Just like with other CircuitMess devices like Nibble or Spencer, we want our components not only to work wonders but to look cool as well! Therefore, we designed some pretty fun patterns that you can see on the back of the board.

Take a closer look at the design on the back of the board

Take a closer look at the design on the back of the board


This microcontroller runs everything, and you could say that this is Jay-D’s brain.

ESP-WROOM-32 is a powerful module mainly used for sound encoding and streaming music. It is reasonably priced considering all its abilities, including the ability to connect to Wi-Fi.

Apart from being famous for sound encoding, ESP-WROOM-32 also controls pictures on display and LED lights.

Due to its complexity and sensitivity, this module is already connected to Jay-D’s main board.

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Headphone jack

This is a headphone jack for standard headphones/earphones.
Sorry - no wireless headphones here!

There is a headphone jack that’s soldered to the bottom of the board. Once you start mixing music on your Jay-D, you can plug in the headphones, and the sound will automatically transfer from the speakers to the headphones.

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Slider potentiometers

Slider potentiometers are used for controlling the volume of the songs that you play.

Depending on the song that you want to remix, you can modify its volume by sliding one of the potentiometers on the left or right. The slider below the display is used to determine which song is more dominant in the remix.

Slider potentiometers are soldered on the board

Slider potentiometers are soldered on the board

Reset button

This one’s pretty self-explanatory - the reset button is used for resetting the whole mix table. You can find this useful in case something gets frozen (which is hopefully never).

USB-C connector

This connector on the top side of the board is used for charging and connecting Jay-D to the computer. Once you connect it to your PC, you’ll be able to program it in CircuitBlocks - a graphical programming interface that helps newbies get into embedded programming. 

SD card holder

SD card holder (SD slot) with an actual SD card inside is located at the bottom side of the board. You can store all your songs on this SD card. If all the memory is used, you’ll be able to replace this one with any microSD card and continue remixing.

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Speaker connectors

Speaker connectors are located at the top side of the board. Each connector is connected to one speaker that is later assembled.

These are not soldered like many other components and connectors (like the headphone jack) on the board.

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LED lights

Have a wild guess - how many LEDs are there on the board?

These LED lights are one of the most exciting components on Jay-D’s board.

There are 144 of them, and the small IS31FL3731 driver is the one controlling them.

This particular LED model is called 0603 (ORHW46G) because they are 0.06in long and 0.03in wide.


Jay-D’s display is connected to its own small board that is soldered to the main board. Many pins need to be connected due to the complexity of the component itself. Don’t worry! Guides that explain this step are quite simple, so we hope you’ll actually enjoy the process of soldering this one.

On this display, you’ll be able to see the songs that you remix, all the settings,
and new featured that you can program in CircuitBlocks a bit later.

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Fun fact

The same display is used in CircuitMess Ringo kit!

Rotary encoders

These are like cherries on top of the cake - rotary encoders are similar to slider potentiometers except for the fact that you don’t slide them, but you rotate them. 

Every professional DJ mix table has to have encoders that add various equalizers to the songs that are being played.

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