4 layers284.7 × 100 mm
EC Pro2 Mainboard
4pplet/EC-Pro-2
Open source replacement PCB kit for the HHKB Pro 2 keyboard.
138 parts3MIT
2 layers77.1 × 137.6 mm
EC23U
davek184/EC23U1Open source numpad Electrostatic Capacitive PCB.
- Size
- 77.1 × 137.6 mm
- Copper layers
- 2
- Thickness
- 1.6 mm
- Parts
- 84
- Nets
- 57
- Pads
- 298
- Tracks, vias
- 469, 194
- Pours
- 2
- Routed
- Yes
- KiCad
- KiCad 6 (file 20211014)
- Created
- 5 Feb 2023
- Updated
- 16 Jan 2023
Overview
EC23U is an open-source printed circuit board by davek184, from the davek184/EC23U repository on GitHub, published under the MIT licence. It is a 2-layer board of 77.1 × 137.6 mm with 84 parts on 57 nets, routed with 469 tracks and 194 vias.
It is built around the SN74AHCT1G125DBV, OPA350UA and 74HC4051, with the PRTR5V0U2X among its other parts. Its parts include 28 switches, 18 resistors, 13 capacitors, 5 ICs and 2 diodes. It belongs with the STM32 boards of this library.
Main components
4
SN74AHCT1G125DBV
SOT-23-5-40℃~+125℃ 1 1 10uA 4.5V~5.5V 6.5ns@5V,15pF 74AHCT 8mA 8mA Output enable Tri-State Unidirectional SOT-23-5 Buffers, Drivers, Receivers, Transceivers ROHSTexas InstrumentsBuffers, Drivers, Receivers, Transceivers
OPA350UA
SOIC-8-55℃~+150℃ 1 10pA 10pA 2.7V~5.5V 22V/us 38MHz 40mA 4uV/℃ 5.2mA 500uV 7nV/√Hz@10kHz 90dB Built-in compensation Rail-to-Rail Input, Rail-to-Rail Output SOIC-8 Operational Amplifier ROHSTexas InstrumentsPrecision Op Amps
74HC4051
SOP-16-40℃~+85℃ 1 170MHz 28ns 29ns 3V~9V 5ns 5pF 80Ω 8:1 SOP-16 Analog Switches, Multiplexers ROHSWuxi I-core ElecAnalog Switches, Multiplexers
PRTR5V0U2X
SOT-143-55℃~+125℃ 0.3pF、0.8pF 100W 10V、15V 5V 6.5V 6A 80nA ESD IEC 61000-4-2、IEC 61000-4-5、IEC 61000-4-4 Three channels Unidirectional SOT-143 ESD and Surge Protection (TVS/ESD) ROHSTECH PUBLICESD And Surge Protection (TVS/ESD)
README
README.mdEC23U
Open source numpad Electrostatic Capacitive PCB.
Introduction
This project is a continuation of my development of open source EC boards.
The supported layout options are the following:
Technical information
- Layout size: 23U layouts with alternative options
- Compatible switches: EC switches (Topre and NIZ)
- Microcontroller: STM32F401
- Connector: Original OEM JST connector
- Firmware compatibility: QMK (with VIA/VIAL support)
- Protection hardware (present on both the mainboard and both controller versions):
- Fused
- ESD protection
- Addressable RGB LED support
- Numlock LED support
Renders and Prototypes
Render
Prototypes
NOTE: The silkscreen text near the JST connector has the GND and VBUS label swapped. This is wrong and have been fixed in the latest revision.
Revisions and relative features
Rev1.0
This revision implements all the main features of the mainboard ad controllers mentioned in the specifications.
RGB header
The mainboard features an RGB header for connecting +5V addressable RGB strips. THe properties of the lighting can be controlled through Vial or by assigning RGB control keycodes on the board itself.
NumLock Indicator
The mainboard features a NumLock indicator LED. The LED is controlled by the MCU and reacts based on the system state. The LED used is a 3.0mm THT LED. Polarity is signalled by the silkscreen. The indicator is optional.
DFU
To access the DFU mode of the mainboard you can perform one of the following actions:
- press the key to which the
QK_BOOTkeycode is assigned (if available) - while plugging in the board short the
Boot0pins on the mainboard
PCB order procedure
Production files
The production can be found in the Production folder.
In there you'll find the main PCB files and the JIS and HHKB plates.
As usual the *.zip files are the gerber files, BOM-*.csv are the BOM (Bill Of Material) files and POS-*.csv are the POS/CPL (Footprint POSition/Component Placement List) files.
Assembly options
Here follows the options to be used for assembly:
- Assembly Side: Bottom
- Confirm Parts Placement:
yes
Copyright notice
This project is not endorse nor sponsored in any way by Topre Corporation and PFU Limited. The HHKB Logo and Topre logo are trademarks of their respective owners.
This project is released under the MIT License. For the license, please refer to the LICENSE.md file.
Parts
84| Qty | Value | Footprint | References |
|---|---|---|---|
| 24 | EC_SW | cipulot_parts:ecs_pad_1U_no_ring | SW2, SW10, SW11, SW12, SW13, SW15, SW16, SW17, SW18, SW19, SW20, SW21, SW22, SW24, SW25, SW26 +8 |
| 8 | 100k | Resistor_SMD:R_0402_1005Metric | R3, R9, R10, R11, R12, R13, R14, R15 |
| 8 | 100n | Capacitor_SMD:C_0402_1005Metric | C4, C5, C6, C7, C8, C10, C12, C13 |
| 7 | Black_Screws | cipulot_parts:HOLE_M2_RF | H1, H2, H4, H5, H6, H7, H8 |
| 5 | 100 | Resistor_SMD:R_0402_1005Metric | R1, R2, R4, R5, R18 |
| 3 | 10k | Resistor_SMD:R_0402_1005Metric | R6, R7, R8 |
| 3 | 1u | Capacitor_SMD:C_0402_1005Metric | C2, C3, C9 |
| 3 | EC_SW | cipulot_parts:ecs_pad_2U_no_ring | SW14, SW23, SW28 |
| 3 | Silver_Screws | cipulot_parts:HOLE_M2_RF | H9, H10, H11 |
| 2 | LOGO | LOGO | G***, G*** |
| 1 | 1k | Resistor_SMD:R_0402_1005Metric | R16 |
| 1 | 220p | Capacitor_SMD:C_0402_1005Metric | C11 |
| 1 | 330 | Capacitor_SMD:C_0402_1005Metric | R17 |
| 1 | 4.7u | Capacitor_SMD:C_0402_1005Metric | C1 |
| 1 | 500mA | Fuse:Fuse_0603_1608Metric | F1 |
| 1 | 74HC4051 | cipulot_parts:TSSOP16 | U3 |
| 1 | 8 MHz | Crystal:Resonator_SMD_Murata_CSTxExxV-3Pin_3.0x1.1mm | Y1 |
| 1 | BOOT0 | Connector_PinHeader_2.00mm:PinHeader_1x02_P2.00mm_Vertical | SW1 |
| 1 | JST | Connector_JST:JST_EH_S4B-EH_1x04_P2.50mm_Horizontal | J1 |
| 1 | LED | LED_THT:LED_D3.0mm | D2 |
| 1 | LOGO | cipulot_parts:Cipulot_all_info | G*** |
| 1 | OPA350 | Package_SO:SOIC-8_3.9x4.9mm_P1.27mm | U4 |
| 1 | PRTR5V0U2X | Package_TO_SOT_SMD:SOT-143 | D1 |
| 1 | Plate_Shield | MountingHole:MountingHole_2.2mm_M2_Pad | H3 |
| 1 | RGB | Connector_PinSocket_2.54mm:PinSocket_1x03_P2.54mm_Vertical | J2 |
| 1 | SN74AHCT1G125 | Package_TO_SOT_SMD:SOT-23-5 | U5 |
| 1 | STM32F401CBUx | Package_DFN_QFN:QFN-48-1EP_7x7mm_P0.5mm_EP5.6x5.6mm | U1 |
| 1 | XC6206PxxxMR | Package_TO_SOT_SMD:SOT-23 | U2 |
Questions
How big is the EC23U PCB?
It measures 77.1 × 137.6 mm and has 2 copper layers, 1.6 mm thick.
What parts does the EC23U use?
84 parts, built around the SN74AHCT1G125DBV, OPA350UA, 74HC4051 and PRTR5V0U2X. The full list of its parts is on this page, with links to each part's symbol and footprint where PCBKit's library has them.
Where can I download the EC23U KiCad files?
From the davek184/EC23U repository on GitHub, at the commit this page was made from: the board is PCB/EC23U.kicad_pcb and its schematic PCB/EC23U.kicad_sch. PCBKit opens the board in the browser, with nothing to install.
Can I use the EC23U design in my own project?
Its repository publishes it under the MIT licence: you may reuse it on that licence's terms (keep the author's notice, and for a copyleft licence share your changes alike).
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