NOMAD Core

Networked Optimized Mobile Access Device

Note: This project is developed with assistance from Claude Sonnet 4.5 via GitHub Copilot.

A modular, 3D-printable forearm-mounted wearable computer platform built around the Raspberry Pi Zero 2W.

What is NOMAD?

NOMAD Core is an open-source wearable computer designed to be worn on your left forearm. It's built from three swappable modules:

• Compute Module - Raspberry Pi Zero 2W with UPS and battery power (1× 18650 cells)
• Display Module - 4.3" screen angled for comfortable viewing
• Input Module - Swappable gamepad or keyboard interface

The entire system mounts to an arm band via a quick-release puck mechanism, making it easy to put on and take off.

Design Philosophy

Core Principle: Modularity
The only fixed standards in NOMAD are the armband mount, M2.5 screws, and 33×33mm puck interface. Everything else is designed to be customized and modified to your needs. Want to use a different SBC? Model your own module mount. Need a bigger battery? Design a custom power module. The baseplate and puck system provide the foundation for whatever you want to build.

• Modular - Swap out individual modules without rebuilding the whole system
• Ergonomic - Worn comfortably on the forearm, no wrist rotation needed
• Open Source - All CAD files, documentation, and designs are freely available
• DIY-Friendly - Designed for 3D printing with common hardware components

Repository Contents

📐 CAD Files (cad/)

OpenSCAD parametric designs for all 3D-printed components:

• 00_assembly_complete.scad - Full system assembly view
• puck_design.scad - Quick-release mounting interface
• baseplate_initial.scad - Raspberry Pi mounting plate
• module_mount.scad - Compute module bracket
• parts/ - Reusable modules (screw cutouts, support columns)
• archive/ - Previous design iterations

📋 Documentation (plans/)

• hardware/DESIGN.md - Complete design specifications and system architecture
• README.md - Overview of planning documentation

📖 Development Docs (docs/)

• SCAD_STYLE_GUIDE.md - OpenSCAD coding standards and conventions

⚙️ Other Directories

• apps/ - Future: User applications for the device
• firmware/ - Future: System configurations and OS images

Getting Started

Prerequisites

• OpenSCAD (or use the included devcontainer)
• 3D printer
• Basic hardware: M2.5 screws, arm band mount

Quick Start

1. Clone the repository

   git clone https://github.com/Merith-TK/nomad.git
   cd nomad

2. Open CAD files

   openscad cad/00_assembly_complete.scad

3. Generate STL files for printing

   openscad -o puck.stl cad/puck_design.scad
   openscad -o baseplate.stl cad/baseplate_initial.scad
   openscad -o module_mount.stl cad/module_mount.scad

4. Print and assemble

   • Slice the STL files in your preferred slicer
   • Print with 20-50% infill
   • Assemble with M2.5 × 16mm screws

Development Environment

This repository includes a devcontainer with OpenSCAD and Python CAD tools pre-installed:

1. Open in VS Code
2. Install "Dev Containers" extension
3. Press F1 → "Dev Containers: Reopen in Container"
4. Wait for container build (first time only)

Contributing CAD Files

When creating or modifying .scad files, please follow the OpenSCAD Style Guide to maintain consistency across the project. The guide covers:

• File structure and organization
• Naming conventions (variables, modules, files)
• Comment standards and documentation
• Parameter grouping and calculated values
• Module design patterns

Hardware Specifications

Component	Specification
Platform	Raspberry Pi Zero 2W
Power	UPS HAT + 1× 18650 battery
Display	4.3" LCD (planned)
Mounting	33×33mm puck interface
Print Volume	~150×80×40mm total

Full specifications in plans/hardware/DESIGN.md

Bill of Materials

Required Components

Component	Description	Link
Raspberry Pi Zero 2WH	Kit includes GPIO header, heatsink, mini-HDMI adapter, and OTG cable	Amazon
Geekworm X306 UPS	UPS HAT for single 18650 battery	Amazon
M2.5 Screw Kit	Assorted M2.5 screws, nuts, lock nuts, and washers	Amazon
Arm Band Mount	Phone-style arm/wristband for wearable mounting	Amazon

USB Hub (Choose One)

Pick based on your connectivity needs:

Option	Ports	Features	Link
Option A	3× USB + Ethernet	Includes GPIO header extender (no GPIO loss)	Amazon
Option B	4× USB + UART	USB-to-UART via micro-USB for PC connection	Amazon

Note: Both USB hubs have a port positioned to fit a USB dongle inside the housing without modification (housing design pending).

Additional Items (Not Linked)

• 1× 18650 battery cell
• 3D printer filament (PLA/PETG recommended)

Current Status

✅ Completed:

• Puck mounting system (fit verified)
• Baseplate for Raspberry Pi 3B+ (test platform)
• Module mount bracket with screw holes
• Modular assembly system with adjustable positioning

🚧 In Progress:

• Display housing design
• Cable management system

📋 Planned:

• Input module dock
• Battery retention system
• Assembly instructions and build guide

Contributing

This is an open-source hardware project. Contributions, suggestions, and improvements are welcome!

License

Open source hardware - details TBD

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Project Status: Early development - functional components, active iteration