DIY Hot Air Coffee Roaster

This repository is my latest attempt to make home coffee roasting simple, reliable, scientific, and affordable.

The tagged v1 release preserves a legacy Nextion-based hardware design. This branch intentionally documents only the current controller, tooling, and firmware layout.

Features

• PID temperature control with profile-based roast automation
• Dual MAX6675 thermocouple monitoring
• Integrated JC4827W543C touchscreen UI using LVGL
• Web console, REST API, and OTA firmware updates
• Artisan integration for roast logging
• Safety systems for over-temperature, sensor faults, and emergency shutdown

Firmware Setup

For complete setup, build, and deployment instructions, see roaster-firmware/README.md.

Hardware Docs

Hardware assembly guidance and the project bill of materials should live at the repository root because they span the whole build, not just the firmware:

• BUILD.md for the physical build and assembly workflow
• BOM.md for the parts list and sourcing notes

The tagged v1 release remains the reference for the legacy hardware design. This branch should document only the current controller and any current-generation enclosure or PCB assets that are restored into the repository.

Quick Start

git clone https://github.com/fredvisser/coffee-roaster.git
cd coffee-roaster/roaster-firmware
./tools/bootstrap.sh
./tools/firmware.sh build --board jc4827w543c

Canonical developer entrypoints:

• ./tools/bootstrap.sh
• ./tools/firmware.sh
• ./tools/tests.sh

Runtime Interfaces

• Web console: http://roaster-dev.local/console
• OTA update page: http://roaster-dev.local/update
• Profile editor: http://roaster-dev.local/profile
• PID workflow: http://roaster-dev.local/pid

Roast Data and Artisan

The firmware can stream roast data to Artisan over WebSockets. For setup and connection steps, see ARTISAN.md. The repository includes an Artisan settings file in Artisan/.

Firmware REST API (summary)

For full details see roaster-firmware/README.md. Key endpoints (id-based):

• GET /api/profiles → { profiles: [{ id, name, active }], active: id }
• POST /api/profiles → Create profile { name, setpoints?, activate? } → returns { ok, id, name, setpoints }
• GET /api/profiles/:id → { id, name, setpoints, active? }
• PUT /api/profiles/:id → Update { name, setpoints, activate? } (id from path wins)
• POST /api/profiles/:id/activate → Activate profile
• DELETE /api/profiles/:id → Delete (409 if active)

Notes:

• Times are seconds in API/UI; firmware stores milliseconds.
• Temp bounds 0–500°F; Fan bounds 0–100%.
• Names are display-only; storage is keyed by opaque ids.

Artisan

For complete Artisan setup, settings import, and connection steps, see ARTISAN.md.