1/24/2026 11:12 PM - Designed the Schematic

I found the relevant libraries to use in kicad which are for the ESP32, Oled and the breakout board. I also added 12 capacitors and 2 resistors to stabilise the power going to the breakout board, all the slide potentiometers and the oled screens.

1/24/2026 11:16 PM - Routed the pcb

I did this by having the relevant capacitors close to the OLED screens and slide potentiometers then the rotary encoders above them.
to make sure i had a proper connection to ground without placing lots of holes between layers i used a fill area.

1/24/2026 11:52 PM - Finding the parts to buy

Unfortunately, the slide Potentiometers could not be found on non-professional websites, so the links I will be using to buy the products are

Slide Potentiometers
https://www.digikey.co.uk/en/products/detail/bourns-inc/PTA6043-2015CPB103/3781230
5 PCS = £7.10

Capacitors

https://www.digikey.co.uk/en/products/detail/vishay-beyschlag-draloric-bc-components/K104K10X7RF5UH5/2356754
10 PCS = £1.08

https://www.digikey.co.uk/en/products/detail/panasonic-electronic-components/ECA-1EM101B/268461
2 PCS = £0.46

Rotary Encoder
https://www.digikey.co.uk/en/products/detail/bourns-inc/PEC11R-4215F-S0024/4499665
2 PCS = £3.26

Female Headers (40 per pack)
https://www.digikey.co.uk/en/products/detail/sullins-connector-solutions/PRPC040SAAN-RC/2775214
3 Packs = £1.23

(To remove the after £33 pay shipping)

ESP32-DEVKITC-32E (£2 more than one on aliexpress)
https://www.digikey.co.uk/en/products/detail/espressif-systems/ESP32-DEVKITC-32E/12091810
1 PCS = £7.42

Rotary Knobs
https://www.digikey.co.uk/en/products/detail/kilo-international/OEJL-90-4-5/710678
2 PCS = £17

Total From Digikey = £37.55

Displays
https://www.aliexpress.com/item/1005008864162501.html
5 PCS = £6.29

TCA9548A 1‑to‑8 I2C Multiplexer
https://www.aliexpress.com/item/1005010790267548.html
1 PCS = £0.96

JLCPCB:

£13.58

Total Cost: £58.37

1/25/2026 12 PM - Designed the CAD

I developed a small contain that has the set cutouts for the pcb, and the components with easy access to the parts. I also attempted to make it look modern by using slots instead of rectangles.
Later there should be some improvements to make sure the design is accurate
Pictures:

1/25/2026 2 PM - Redo the Schematic and pcb

I was doing a check on the layout of pins on schematic and with the real components and it didnt match so i changed parts of the schematic and removed some components as the parts i am buying has them built in.

1/27/2026 11:08 PM - Redesigned the CAD

a V2 of the cad which has completely new safety features and make sure it is easy to use.
What has been added:

• A small plate at the bottom to make it look raised without directly making the bottom layer really thick.
• Standoff so there will not be a need to clip any pins off.
• hinge so that there wont be a need for actually using screws you can use a paperclip.

1/27/2026 11:12 PM - PCB Revision

Added a filled zone/ground pour, added text on the back and added mounting holes to acomodate the standoffs i have placed in the cad and made sure it acutally goes through the design rules checker.

2/15/2026 12 AM - Complete Redesign

I was doing research when i found out getting 5 0.94inch screen is not that great so i have upgraded this to 1 2.2-inch TFT screen and to accommodate this i will also upgrade the microcontroller which is acutally somehow cheaper ESP32-S3-Devboard i had some troubles trying to put this onto my pcb but i have modded it because for some reason expressif specs are not the same as the ones you actually buy/clones.

I redesigned the CAD so the new PCB fits inside without a problem with a custom hinge, which was helped by a fusion tutorial that I found and completely removes the need of screws.

All Changes are now on GitHub (Main)

Schematic

PCB

CAD

BOM

Total Of Digikey: £37.00

Total Of Aliexpress: £12.30

Total Of JLCPCB and JLC3DP: £33.44 or $45.55

Grand Total: £82.74

Screenshots of the cart:

2/15/2026 12 PM - Image of PCB

I am reuploading the image of the PCB because it wasn't very clear from the PDF I got Kicad to print

PCB

Top Side of the PCB

Back Side of the PCB

3/21/2026 - Firmware and BOM

BOM

The complete list of hardware required to build this project.

Digikey

Digikey Total: £45.37

AliExpress

Estimated AliExpress Total: £13.82 without discount

Manufacturing

JLCPCB Total: $21.08 or £15.80

For 3D printing, filament is about £10.25 from Bambu Labs.

Grand Total: £85.24

Firmware

I have built a companion software so that the pc and ESP32 can communicate.
The ESP32 will have software to control the volume of apps, microphones, OBS and have an EQ fine-tuning section using EqualizerAPO
The 5 sliders and rotary encoders will be controlled like this:

Channel Layout

EQ Mode

Button 1 toggles EQ mode — faders map to 80Hz, 320Hz, 1kHz, 3.2kHz, 10kHz via EqualizerAPO.

Images for proof