ENABLE_DEVICE_RESPONSE¶

Flag to enable unified device response protocol.

Controls whether the firmware uses a unified device_response_t type for all output messages (responses and events) or legacy separate response_t/event_t types.

v2 (Always Enabled)¶

In v2, the unified device response protocol is a standard feature — always enabled, no flag required.

All output uses device_response_t:

{"type":"response","status":"ok","sent_us":1748012345678901,"version":"2.6.0"}
{"type":"event","status":"ok","sent_us":1748012345678901,"hit1":45,"hit2":38,"hit3":42,"detected_us":1748012345678456}

v1 (Configurable)¶

In v1, the unified protocol is opt-in via ENABLE_DEVICE_RESPONSE.

Default¶

v1: Disabled by default (ENABLE_DEVICE_RESPONSE=0, legacy protocol)

Options¶

ENABLE_DEVICE_RESPONSE=1: Use unified device_response_t for all output (v1.12.0+)
ENABLE_DEVICE_RESPONSE=0: Use legacy separate response_t/event_t types (default)

Override with `platformio.override.ini`¶

[env:esp32dev-v1]
build_flags =
    -D ENABLE_DEVICE_RESPONSE=1

Features (when enabled)¶

Single unified message structure for all output
JSON schema validation (strict and flexible modes)
Type and status enumerations
Builder functions for safe initialization
Error code standardization

JSON Schemas¶

All messages conform to:

docs/schemas/device-response.json — Strict validation (recommended for code generation)
docs/schemas/device-response-flexible.json — Permissive validation (for protocol evolution)

Memory Overhead¶

Flash: ~1-2KB (builder functions)
RAM: Minimal (no additional state)
Zero overhead when disabled: All code excluded by preprocessor

History¶

v1.12.0 — Initial implementation, opt-in (ENABLE_DEVICE_RESPONSE=1)
v2.0.0 — Promoted to always-enabled standard feature