

555-timer
PCB designs
- Size
- 16.5 × 15.5 mm
- Copper layers
- 2
- Thickness
- 1.6 mm
- Parts
- 17
- Nets
- 11
- Pads
- 36
- Tracks, vias
- 82, 15
- Pours
- 1
- Routed
- Yes
- KiCad
- KiCad 8.0 (file 20240108)
- Created
- 22 Mar 2024
- Updated
- 11 Sep 2026
Overview
555-timer is an open-source printed circuit board by smkent, from the smkent/pcb repository on GitHub, published under the CC-BY-SA-4.0 licence. It is a 2-layer board of 16.5 × 15.5 mm with 17 parts on 11 nets, routed with 82 tracks and 15 vias.
It is built around the NE555. Its parts include 6 resistors, 2 capacitors, 2 diodes, 2 connectors and 1 IC.
Main components
1README
README.mdPCB designs
A monorepository of my PCB designs created with KiCAD 8.
Layout and Workflow
Custom symbols and footprints are located in libraries, which
is shared between PCB projects using ${KIPRJMOD}.
Individual PCB projects (e.g. *.kicad_pro and friends) are located within
within pcb for active projects, or
pcb-archived for archived projects.
When a PCB is ordered from a project, fabrication outputs are created and
in the project's fab subdirectory and committed to the repository.
Setup
Ensure pipx is installed:
pip install pipxInstall scons:
pipx install sconsInstall KiCAD-related dependencies using the system site packages directory:
pipx install --system-site-packages kikit interactivehtmlbomBuild
To render all outputs, simply run scons.
To render outputs for a particular board, run scons -u within that board's
project subdirectory.
Licenses
Individual hardware designs in this repository may use different licenses. The following licenses apply unless an included design directory specifies different license(s).
- Hardware materials and designs are licensed under CERN Open Hardware License version 2.0 Permissive (CERN-OHL-P v2) (text). The version control history of this repository serves as the changes file.
- Software is licensed under the GNU General Public License v3.0 (GPL-3.0) (text)
- All documentation is licensed under Creative Commons Attribution-ShareAlike 4.0 International (CC-BY-SA-4.0) (text)
The lcsc KiCAD symbols,
footprints, and 3D models
libraries were created using easyeda2kicad
(pypi), which are from LCSC. More info about
easyeda2kicad
Parts
17| Qty | Value | Footprint | References |
|---|---|---|---|
| 3 | 0R | Resistor_SMD:R_0603_1608Metric_Pad0.98x0.95mm_HandSolder | R0, R3, R4 |
| 2 | 1K | Resistor_SMD:R_0603_1608Metric_Pad0.98x0.95mm_HandSolder | R5, R6 |
| 2 | LED_Small | custom:LED_0603_1608Metric_Pad1.05x0.95mm_HandSolder_simple | LED1, LED2 |
| 1 | 0u1 | discrete:C_0603_1608Metric_Pad1.08x0.95mm_HandSolder | C0 |
| 1 | 10K | Resistor_SMD:R_0603_1608Metric_Pad0.98x0.95mm_HandSolder | R1 |
| 1 | 1u | custom:C_Combo_CP_Elec_5x5.4 | C1 |
| 1 | 500K | discrete:Potentiometer_3.8mmx3.0mm_Vertical | RV1 |
| 1 | LOGO | graphics:oshw-logo-2mm | G*** |
| 1 | LOGO | graphics:wa-state-heart-3mm | G*** |
| 1 | LOGO | graphics:oshw-logo-1.5mm | G*** |
| 1 | NE555 | Package_SO:SOIC-8_3.9x4.9mm_P1.27mm | U1 |
| 1 | Pin headers | custom:PinHeader_1x02_P2.54mm_Vertical_simple | J2 |
| 1 | Pin headers | custom:PinHeader_1x03_P2.54mm_Vertical_simple_pad2gnd | J1 |
Questions
How big is the 555-timer PCB?
It measures 16.5 × 15.5 mm and has 2 copper layers, 1.6 mm thick.
What parts does the 555-timer use?
17 parts, built around the NE555. 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 555-timer KiCad files?
From the smkent/pcb repository on GitHub, at the commit this page was made from: the board is pcb/jigs/555-timer/555-timer.kicad_pcb. PCBKit opens the board in the browser, with nothing to install.
Can I use the 555-timer design in my own project?
Its repository publishes it under the CC-BY-SA-4.0 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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