[ English | 日本語 (docs/ja/README.md) ]
A tougher, enclosure-friendly board for running your Arduino sketches in the real world.
ADX CORE-A is an open-hardware microcontroller board designed for projects that need to step off the workbench and run reliably inside real-world spaces—neatly mounted, cleanly wired, and built with practical protections.
Prototyping on a workbench with a breadboard is an incredible, creative way to bring ideas to life.
However, when it is time to move those sketches into a permanent spot—a workshop dust collector, a greenhouse watering rig, a storefront display, or a custom wall-mounted clock—makers often run into common physical challenges:
- Awkward Mounting: Mounting holes are often too close to delicate traces, making tightening M3 screws feel risky.
- Hard to Enclose: Wires and connectors stick out in multiple directions, requiring complicated multi-sided cutouts in enclosures.
- Loose Wiring: Standard jumper wires can loosen under minor vibration or accidental tugs.
- Maintenance Friction: Taking a heavy laptop to a crawl space or ladder just to change a few lines of code is inconvenient.
ADX addresses these hurdles through a grounded philosophy: "The Working Arduino."
Not a complicated, high-cost industrial PLC, but an accessible, slightly tougher companion that makes putting your projects into real enclosures natural and trouble-free.
The foundation of ADX is an open physical specification designed to ensure boards and modules mount cleanly and wire tidily.
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【 ADX HARDWARE STANDARD 】
・8748 Form Factor (87.0 mm × 48.0 mm outline)
・Corner M3 Mounting Holes with Φ5.0 mm Washer Clearances
・Rail-Grab Margins for Slot-In & Snap-Fit Enclosures
・Unidirectional I/F Edge (All external wiring on one face)
・20-Pin Robust Bus (Direct stack & flat IDC ribbon cable)
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│
┌──────────────────────────┴──────────────────────────┐
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【 Main Core Board 】 【 Modular CARDs 】
ADX CORE-A (Active R&D) ADX CARD Ecosystem
・Tougher, Enclosure-Native Core ・Prototyping CARD
・Spring Terminals & Protection ・AAA Battery CARD
・(See hardware/CORE-A/ for notes) ・3D-Print Mount STLs
- Dimensions:
87.0 mm × 48.0 mm(3425 mil × 1890 mil). - Clearance for Real Screws: Standardized 4-corner M3 mounting holes (
77.0 mm × 38.0 mmpitch) with generous Φ5.0 mm washer clearances, ensuring screw heads and washers never crush PCB traces. - Enclosure Grab Margins: Dedicated keep-out zones along the board edges support slot-in rail mounting and 3D-printed snap-fit tabs.
External field connections are strictly aligned along a single edge of the PCB.
By eliminating multi-directional wire protrusions, enclosure design is simplified—you only need to plan cutouts and openings on one face of your project box.
Expansion modules (CARDs) connect through a unified 20-pin expansion bus (VDD, GND, GPIO, ADC, DAC, I2C, SPI, UART).
- Direct Stack: CARDs can stack directly on top of or beneath the core board.
- Flexible IDC Ribbon Cable: The bus is standardized for off-the-shelf flat IDC ribbon cables. In shallow boxes, modules can sit side-by-side; in deep boxes, they can stack vertically—adapting to your enclosure shape rather than dictating it.
ADX is actively developing dedicated hardware solutions to bring "The Working Arduino" to life.
┌────────────────────────────────────────────────────────────────────────┐
│ 【 ADX CORE-A 】(Main Board — In Active R&D) │
│ - Microchip ATtiny1616-MNR MCU (16KB Flash / 2KB SRAM) │
│ - Push-in spring terminal blocks for vibration-resistant wiring │
│ - Protective circuitry designed to cushion external electrical noise │
│ - Native 8748 Form Factor with standardized corner M3 mounts │
└───────────────────────────────────┬────────────────────────────────────┘
│ Field connection
▼
┌────────────────────────────────────────────────────────────────────────┐
│ 【 RPR4 Smart Probe 】(Adapter Probe — In Active R&D) │
│ - Experimental tool exploring browser WebSerial connectivity │
│ - Researched to enable quick sketch updates directly in the field │
│ - Compact form factor to avoid carrying heavy laptops to deployed rigs│
└────────────────────────────────────────────────────────────────────────┘
CORE-A is the primary core board engineered for long-term installation.
- Push-in Spring Terminals: Screwless terminal blocks allow solid or ferruled wires to be inserted securely without loosening over time.
- Protection by Design: Circuitry designed to reduce the risk of accidental wiring damage, keeping the board steady when operating near switching devices or longer cable runs.
- For detailed circuit schematics, protection topology, and current revision notes, please refer to hardware/CORE-A/concept.md.
RPR4 is an experimental adapter currently under research and prototyping.
- Built to explore convenient field servicing—such as quick parameter tweaks and sketch updates over browser-based WebSerial—aiming to free makers from balancing a laptop in awkward installation spaces.
- For prototype development progress, please refer to hardware/RPR4/.
You do not need to learn a new programming language or switch to unfamiliar development tools.
- Familiar Code: Programs can be written with the standard Arduino language and libraries using
megaTinyCore. - Lightweight & Efficient: Driven by an ATtiny1616, CORE-A keeps power consumption modest and startup instantaneous, making it well-suited for everyday sensing, timing, and device control tasks.
ADX boards expand seamlessly through modular CARDs sharing the same 8748 physical profile:
- Prototyping CARD: A universal 2.54 mm pitch breadboard area with pass-through 20-pin bus access, keeping custom circuits tidy and securely mountable.
- AAA 2S Battery CARD: Onboard boost circuitry providing 5V to the bus from two standard AAA batteries for standalone and portable projects.
- Open 3D-Print STLs: Downloadable STL/STEP files for customizable brackets, rail guides, and snap-fit project boxes.
All hardware designs, dimensions, and specifications are open source:
- 8748 Form Factor Specification: docs/en/8748_formfactor.md | docs/ja/8748_formfactor.md
- ADX 20-Pin Bus Pinout: docs/memo/adx_pinout_v2.md | docs/ja/adx_pinout_v2.md
- CORE-A Hardware Notes: hardware/CORE-A/concept.md
- RPR4 Development Notes: hardware/RPR4/
- Documentation Reorganization Plan: memo/PLAN/WORKING_ARDUINO_CORE-A_DOCUMENTATION_PLAN.md