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HolyGrail

whbCool·HolyGrail·PCB/DarkMagic.kicad_pcb

HolyGrail PCB layout, top view — open source ESP32 board by whbCool
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About the HolyGrail PCB

HolyGrail is an open source ESP32 PCB design by whbCool, published on GitHub. It is a 6-layer board measuring 157 × 73 mm, with 195 components from 61 distinct parts.

Its main chip is the ESP32-WROOM-32UE-N16, from the ESP32 family. Other key parts include the 5PB1106PGGI8, MMBT3904-AQ, W5500, CP2102N-A02-GQFN24 and USBLC6-2SC6. By type, the board carries 93 resistors, 52 capacitors, 22 ICs, 6 LEDs, 5 connectors and 5 diodes.

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

From the project

Code for the Holy Grail PCB

The Holy Grail is a custom PCB, designed for the Indiana Jones puzzle as a part of TEA@CPP's "Retro Rewind" 2026 Escape Room.

This repository includes the KiCad schematic, as well as the code database for the board.

For more details on the code, check out the introductory walkthrough here.

Major Components: - ESP32-WROOM-32UE - SC16IS752IPW128 - CD74HC138QM96Q1 - SN74LVC1G125DBVT - CDCLVC1106PWR - 7447715003 - LMR33640 - AP63205WU-7 - 5747842-2 - W5500 - USBLC6-2SC6 - TMJ0026ABNL - MMBT3904 - CP2102N-A02-GQFN24 - 1812L15024MR - LM393DR

HolyGrail, from the project README
From the project README

Main components on the HolyGrail

5PB1106PGGI8ESP32-WROOM-32UE-N16MMBT3904-AQW5500CP2102N-A02-GQFN24USBLC6-2SC6LMR33640ADDARSN74LVC1G125DBVRLM3940IMP-3.3/NOPBLM393DRSC16IS752IPW,128CD74HC138QM96Q1

HolyGrail bill of materials (BOM)

195 components, 61 distinct parts — part numbers from the project's BOM.

QtyPartRefs
1
5PB1106PGGI8
IC1
1
ESP32-WROOM-32UE-N16
IC2
4
MMBT3904-AQ
IC3, IC4, IC10, IC11
1
W5500
IC5
1
CP2102N-A02-GQFN24
IC6
1
USBLC6-2SC6
IC7
1
LMR33640ADDAR
IC8
3
SN74LVC1G125DBVR
SN74LVC1G125DBVT
IC12, IC13, IC15
1
LM3940IMP-3.3/NOPB
LM3940IMP-3.3_NOPB
IC14
1
LM393DR
IC17
6
SC16IS752IPW,128
SC16IS752IPW_128
U1, U2, U4, U5, U6, U7
1
CD74HC138QM96Q1
U3
1
SQ2319ADS-T1_BE3
Q1
1
SQ2348ES-T1_BE3
Q2
1
ASE-14.7456MHZ-LC-T
Y2
1
ASE-25.000MHZ-LC-T
Y3
1
UJ20-C-H-G-SMT-1A-P16-TR
USB_C_Receptacle_USB2.0_16P
J1
1
TMJ0026ABNL
J2
2
DB25-SA-M2
5747842-2
J3, J6
1
171825-2
J7
Show 41 more
QtyPartRefs
1
NANOSMDC050F/13.2-2
NANOSMDC050F_13.2-2
F1
1
1812L150/24MR
1812L150_24MR
F2
1
1206L075SLYR
F3
2
B57442V5103J062
RT1, RT2
2
B3U-1000P-B
S1, S2
2
HSMG-C170
3V1, STATUS1
1
HSMA-C170
5V1
1
HSMC-C170
12V1
2
HSMN-C170
IRQ1, SCLK1
2
B130-13-F
D1, D5
1
SMBJ26A
D2
2
1N4148W-7-F
1N4148W
D3, D4
1
7447715003
L1
35
CL21B104KCC5PNC
0.1uF
C1, C2, C6, C8, C10, C12, C13, C14 +27
4
CL21A106KBYQNNE
10uF
C3, C4, C32, C38
2
CL21A475KACLRNC
4.7uF
C5, C7
1
CL21B103KC6WPNC
4.7uF
C11
1
EEH-ZA1K330P
33uF
C33
5
CL21X226MQQNNNG
22uF
C39, C40, C49, C52, C53
1
EEH-ZA1K470P
47uF
C41
1
CL21B105KOFNNWE
1uF
C48
1
CL21B224KBFNFNE
220nF
C51
1
CL21C390JBANNNC
39pF
C54
5
ERJ-PC6B3300V
330
R1, R2, R3, R21, R22
15
ERA-6AEB103V
10k
R4, R5, R14, R17, R19, R20, R23, R24 +7
2
ERA-6ARB4751V
4.7K
R6, R7
44
ERA-6AHD330V
33
R8, R9, R10, R11, R12, R13, R29, R30 +36
2
ERA-6ARB512V
5.1k
R15, R16
1
ERJ-UP6F1242V
12.4k
R18
2
ERJ-UP6D4701V
4.7k
R31, R54
1
ERJ-S06J681V
680
R52
1
ERA-6AEB152V
1.5k
R53
2
ERA-6AEB2551V
2.55K
R67, R68
6
ERA-6APB103V
10K
R69, R70, R71, R72, R73, R74
2
ERA-6AEB105V
1M
R75, R76
1
ERA-6AEB2212V
22.1k
R82
1
ERA-6AEB4752V
47.5k
R83
1
ERJ-PB6B2492V
24.9k
R85
2
ERA-6AEB104V
100k
R86, R87
4
ERJ-P06F49R9V
49.9
R89, R90, R91, R92
1
ERA-6AEB103V
4.7k
R94

HolyGrail design files

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

HolyGrail: common questions

What microcontroller does the HolyGrail use?

The HolyGrail is built around the ESP32-WROOM-32UE-N16, from the ESP32 family.

How big is the HolyGrail PCB?

The HolyGrail measures 157 × 73 mm, has 6 copper layers and is 1.5744 mm thick.

How many components are on the HolyGrail?

195 components, from 61 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 HolyGrail design files?

From the whbCool/HolyGrail 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 HolyGrail design in my own project?

The repository has no license, so all rights stay with whbCool. Use it as a reference, and ask the author before reusing the design.

Can I test firmware for the HolyGrail 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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