

Earring
Collection of microcontroller projects
- Size
- 75 × 92.5 mm
- Copper layers
- 2
- Thickness
- 1.6 mm
- Parts
- 60
- Nets
- 36
- Pads
- 217
- Tracks, vias
- 684, 65
- Routed
- Yes
- KiCad
- KiCad 9.0 (file 20241229)
- Created
- 16 Nov 2018
- Updated
- 2 Sep 2026
Overview
Earring is an open-source printed circuit board by aykevl, from the aykevl/things repository on GitHub. It is a 2-layer board of 75 × 92.5 mm with 60 parts on 36 nets, routed with 684 tracks and 65 vias.
It is built around the AO3401A. Its parts include 36 diodes, 12 resistors, 1 capacitor, 1 IC and 1 transistor. It belongs with the STM32 boards of this library.
Main components
1README
README.mdSandbox for electronics projects
This is my personal stash of small electronics projects, usually written using TinyGo.
I won't guarantee anything about it. All I can say is that it did work for me at some point and I like sharing what I made. Many things are written once and then mostly forgotten so I probably won't provide any support for any of the code.
License
Feel free to use this code however you wish (in other words, you can treat it as public domain). Especially for small parts I won't mind if you just copy it in your project. For larger pieces of code or if you copy a project entirely, I would appreciate attribution somewhere (but it's not required).
If you prefer having an actual license for legal reasons, you can use the MIT license - but again, the code is public domain so no need to actually use this:
Copyright 2023 Ayke van Laethem
Permission is hereby granted, free of charge, to any person obtaining a
copy of this software and associated documentation files (the
“Software”), to deal in the Software without restriction, including
without limitation the rights to use, copy, modify, merge, publish,
distribute, sublicense, and/or sell copies of the Software, and to
permit persons to whom the Software is furnished to do so, subject to
the following conditions:
The above copyright notice and this permission notice shall be included
in all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED “AS IS”, WITHOUT WARRANTY OF ANY KIND, EXPRESS
OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.Parts
60| Qty | Value | Footprint | References |
|---|---|---|---|
| 36 | LED_ARGB | Custom:NH-Z1415RGBA-SG | D1, D2, D10, D11, D12, D13, D14, D15, D16, D17, D18, D19, D20, D21, D22, D23 +20 |
| 8 | 1k | Resistor_SMD:R_0402_1005Metric | R1, R2, R4, R5, R7, R8, R10, R11 |
| 6 | ToolingHole | Custom:ToolingHole_JLCPCB | H1, H1, H1, H1, H1, H1 |
| 4 | 220 | Resistor_SMD:R_0402_1005Metric | R3, R6, R9, R12 |
| 1 | 10uF | Capacitor_SMD:C_0402_1005Metric | C2 |
| 1 | AO3401A | Package_TO_SOT_SMD:SOT-23 | Q1 |
| 1 | Battery_Cell | Custom:MY-1220-03 | BT1 |
| 1 | Conn_01x05 | Custom:ProgramHeader | J1 |
| 1 | STM32L031G6Ux | Package_DFN_QFN:QFN-28_4x4mm_P0.5mm | U2 |
| 1 | SW_Push | Button_Switch_SMD:SW_Push_SPST_NO_Alps_SKRK | SW1 |
Questions
How big is the Earring PCB?
It measures 75 × 92.5 mm and has 2 copper layers, 1.6 mm thick.
What parts does the Earring use?
60 parts, built around the AO3401A. 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 Earring KiCad files?
From the aykevl/things repository on GitHub, at the commit this page was made from: the board is earring-ring-rgb36/earring/earring.kicad_pcb and its schematic amulet-supercap/amulet.kicad_sch. PCBKit opens the board in the browser, with nothing to install.
Can I use the Earring design in my own project?
Its repository states no licence, so its author keeps all rights: ask aykevl before reusing the design.
More from aykevl/things
5- 2 layers80 × 80 mm

- 2 layers

- 2 layers50 × 30 mm

- 2 layers15 × 20 mm

- 2 layers40 × 60 mm

Similar boards
- 2 layers192.2 × 150.5 mm

- 4 layers102.9 × 96.7 mm

PicoGUS chipdown
polpo/picogus
Emulation of ISA sound cards and CD-ROM on Raspberry Pi Pico (GUS, SB/Adlib, MPU-401, Tandy, CMS, Panasonic CD-ROM) with USB mouse/joystick support
99 parts805 - 6 layers237.9 × 80.5 mm

XG Mobile Dock
osy/XG_Mobile_Station
Open source eGPU dock for ROG Ally and ROG Flow
300 parts712CC-BY-4.0 - 2 layers60 × 111.3 mm

Silkscreen pcb
iandchasse/silkscreen-pcb
Silkscreen: open-hardware ESP32-S3 e-paper reader mainboard (KiCad 9). Formerly the de-link hub.
189 parts589CERN-OHL-S-2.0 - 2 layers89.2 × 82.6 mm

Desktop 50 Pin TopConn
BlueSCSI/BlueSCSI-v2
BlueSCSI v2/Ultra - an open source, open hardware, SCSI emulator using the Pi Pico PR2040 and Pico 2 RP2350
108 parts459GPL-3.0 - 4 layers55 × 55 mm

RBoard
pms67/LittleBrain-STM32F4-Sensorboard
STM32F4-based PCB interfacing with a variety of sensors.
90 parts339 - 6 layers55 × 95 mm

- 4 layers243.8 × 171.5 mm
