HardLabs

EC Pro2 Mainboard

4pplet·EC-Pro-2·PCB/EC_Pro2_Mainboard/EC_Pro2_Mainboard.kicad_pcb

EC Pro2 Mainboard PCB layout, top view — open source STM32 board by 4pplet
Simulate this board

About the EC Pro2 Mainboard PCB

EC Pro2 Mainboard is an open source STM32 PCB design by 4pplet, published on GitHub under the MIT license. It is a 4-layer board measuring 284.7 × 100 mm, with 49 components from 27 distinct parts.

Its main chip is the MIC2026-2BM, from the STM32 family. Other key parts include the SRV05-4, FE1.1 and SN74AHCT1G125. By type, the board carries 26 resistors, 13 capacitors, 6 ICs, 1 crystal, 1 connector and 1 fuse.

It belongs with the keyboards designs in this gallery.

From the project

Open source replacement PCB kit for the HHKB Pro 2 keyboard.

Open source HHKB Pro2 Controller and mainboard.

This project is a continuation of my development of open source EC boards.

The supported layout options are the following:

- Layout size: HHKB Pro2 ANSI and some additions - Compatible switches: EC switches (Topre and NIZ) - Microcontroller: STM32F401 - Connector: JST connector for controller board - Firmware compatibility: QMK (with VIA/VIAL support) - Protection hardware (present on both the mainboard and both controller versions): - Fused - ESD protection

EC Pro2 Mainboard, from the project README
From the project README

Main components on the EC Pro2 Mainboard

MIC2026-2BMSRV05-4FE1.1SN74AHCT1G125

EC Pro2 Mainboard bill of materials (BOM)

49 components, 27 distinct parts — part numbers from the project's BOM.

QtyPartRefs
1
MIC2026-2BM
STM32F401CBUx
U1
1
SRV05-4
XC6206PxxxMR
U2
1
SRV05-4
74HC4051
U3
1
SRV05-4
OPA350
U4
1
FE1.1
74HC4051
U5
1
SN74AHCT1G125
U6
1
12MHZ
8 MHz
Y1
1
C145956
JST
J1
1
500MA
500mA
F1
1
PRTR5V0U2X
D1
1
100N
4.7u
C1
1
100N
1u
C2
1
10U
1u
C3
2
100U
100n
C4, C7
3
100N
100n
C5, C10, C12
1
10U
100n
C6
1
30P
100n
C8
1
30P
1u
C9
1
100N
220p
C11
1
100n
C13
Show 7 more
QtyPartRefs
2
5.1K
100
R1, R2
3
10K
100
R3, R4, R6
3
10K
100k
R5, R10, R11
3
10K
10k
R7, R8, R9
1
2.7K
100k
R12
13
100k
R13, R14, R15, R16, R17, R18, R20, R21 +5
1
1k
R19

EC Pro2 Mainboard design files

The KiCad project lives in the 4pplet/EC-Pro-2 repository on GitHub; these links point at the commit this page was built from.

EC Pro2 Mainboard: common questions

What microcontroller does the EC Pro2 Mainboard use?

The EC Pro2 Mainboard is built around the MIC2026-2BM, from the STM32 family.

How big is the EC Pro2 Mainboard PCB?

The EC Pro2 Mainboard measures 284.7 × 100 mm, has 4 copper layers and is 1.59 mm thick.

How many components are on the EC Pro2 Mainboard?

49 components, from 27 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 EC Pro2 Mainboard design files?

From the 4pplet/EC-Pro-2 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 EC Pro2 Mainboard design in my own project?

Yes, under the terms of its MIT license, which 4pplet chose for the repository.

Can I test firmware for the EC Pro2 Mainboard without the hardware?

Yes. HardLabs builds a simulation of the board from its netlist and BOM, so you can run and debug STM32 firmware against it before you order a PCB.

More boards in EC-Pro-2

Similar boards