Constraints

This chapter lists constraints that the Station’s architecture must work within.

Technical Constraints

Constraint	Impact
Runs on a single Raspberry Pi with a touch display, as established in System Design	Available CPU, GPU, and memory are limited compared to a desktop, and the UI must be fully operable by touch alone.
Pods are reachable only through the shared wire protocol over USB CDC (Protocol, ADR-002)	The Station cannot assume any other channel to a Pod. All hardware control is mediated by that protocol.
The Station must remain the sole initiator of all communication with a Pod (ADR-003)	The Station’s architecture must not introduce any path for a Pod to act without an originating Station request.
Recipes, ingredients, and glasses are provided as data validated against a published schema, not as code	The Station must be able to load and act on this data without a rebuild whenever it changes.

Constraint

Impact

Runs on a single Raspberry Pi with a touch display, as established in System Design

Available CPU, GPU, and memory are limited compared to a desktop, and the UI must be fully operable by touch alone.

Pods are reachable only through the shared wire protocol over USB CDC (Protocol, ADR-002)

The Station cannot assume any other channel to a Pod. All hardware control is mediated by that protocol.

The Station must remain the sole initiator of all communication with a Pod (ADR-003)

The Station’s architecture must not introduce any path for a Pod to act without an originating Station request.

Recipes, ingredients, and glasses are provided as data validated against a published schema, not as code

The Station must be able to load and act on this data without a rebuild whenever it changes.

Conventions

Domain terms and their naming across the Station’s code follow the project-wide convention in Naming Conventions. Architecturally significant choices made while designing the Station are recorded as ADRs alongside the code, in the same style as the machine-wide ADRs, rather than left implicit.

Continue with Context and Scope.