HardLabs

FreeEEG

eric5512·FreeEEG·Electronics/FreeEEG.kicad_pcb

FreeEEG PCB layout, top view — open source ESP32 board by eric5512
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About the FreeEEG PCB

FreeEEG is an open source ESP32 PCB design by eric5512, published on GitHub under the MIT license. It is a 4-layer board measuring 64 × 46.1 mm, with 94 components from 50 distinct parts.

Its main chip is the ESP32-S3-WROOM-1, from the ESP32 family. Other key parts include the ICM-42670-P, BQ25185DLHR, ADS1299, OPA376xxDBV and TPS610997YFFR. By type, the board carries 36 capacitors, 36 resistors, 7 ICs, 5 connectors, 3 switches and 3 diodes.

It belongs with the iot & wireless, sensors and power & battery designs in this gallery.

From the project

An open hardware EEG system implementation

FreeEEG is a low-cost, open-source electroencephalography (EEG) acquisition platform designed for educational, experimental, and research-oriented applications. The project aims to provide an accessible and modifiable EEG system for researchers, students, and hobbyists who need direct control over the acquisition hardware, firmware, and data interface.

The platform is based on the Texas Instruments ADS1299 analog front-end and an ESP32-S3 microcontroller. It supports multichannel EEG acquisition, real-time wireless data transmission, onboard storage, and motion sensing through an integrated…

Main components on the FreeEEG

ICM-42670-PBQ25185DLHRADS1299ESP32-S3-WROOM-1OPA376xxDBVTPS610997YFFRTPS628438DRL

FreeEEG bill of materials (BOM)

94 components, 50 distinct parts — part numbers from the project's BOM.

QtyPartRefs
1
ICM-42670-P
IC1
1
BQ25185DLHR
IC2
1
ADS1299
U1
1
ESP32-S3-WROOM-1
U3
1
OPA376xxDBV
U4
1
TPS610997YFFR
U7
1
TPS628438DRL
U8
1
ConnElectrodes
J1
1
10137065-00021LF
J2
1
Conn_I2C
J3
1
battery_conn
J4
1
ExtTrig
J6
1
TF-01A
MICRO_SD1
1
ICS-43434
MK1
1
ON_SW
SW1
1
SEL_SW
SW2
1
RST_BTN
SW3
1
LED_AMBAR
D1
1
LED_BLUE
D2
1
WS2812B
D3
Show 30 more
QtyPartRefs
1
1u
L1
1
2.2u
L2
3
10u
C1, C5, C31
1
10n
C2
3
1u
C3, C25, C27
1
100n
C4
5
10u
C6, C7, C28, C50, C51
1
4.7n
C24
2
1u
C26, C52
1
4.7u
C29
4
10n
C30, C46, C47, C48
6
0.1u
C32, C36, C39, C41, C43, C45
1
100u
C33
8
1u
C34, C35, C37, C38, C40, C42, C44, C49
11
10k
R1, R2, R3, R4, R5, R12, R13, R15 +3
2
5.1k
R6, R7
4
33k
R8, R9, R10, R11
1
249k
R14
1
13k
R16
1
619
R17
1
22k
R18
1
150
R19
1
120
R20
2
4.99k
R31, R49
1
50k
R34
1
392k
R36
2
2M
R37, R38
1
100k
R39
2
4.7k
R47, R48
4
R_Pack04_SIP_Split
RN1, RN2, RN3, RN4

FreeEEG design files

The KiCad project lives in the eric5512/FreeEEG repository on GitHub; these links point at the commit this page was built from.

FreeEEG: common questions

What microcontroller does the FreeEEG use?

The FreeEEG is built around the ESP32-S3-WROOM-1, from the ESP32 family.

How big is the FreeEEG PCB?

The FreeEEG measures 64 × 46.1 mm, has 4 copper layers and is 1.6 mm thick.

How many components are on the FreeEEG?

94 components, from 50 distinct parts, with part numbers taken from the project's own BOM. The full bill of materials is listed on this page.

Where can I download the FreeEEG design files?

From the eric5512/FreeEEG repository on GitHub, which has the KiCad layout, the schematic and the BOM; the links under Design files point to each one.

Can I use the FreeEEG design in my own project?

Yes, under the terms of its MIT license, which eric5512 chose for the repository.

Can I test firmware for the FreeEEG without the hardware?

Yes. HardLabs builds a simulation of the board from its netlist and BOM, so you can run and debug ESP32 firmware against it before you order a PCB.

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