froling_modbus2mqtt/PROMPT.md

Prompt - Modbus to MQTT App

Use these development guidelines for this repository.

Goals

• Keep the app config-driven and backward compatible.
• Avoid breaking MQTT topics or HA discovery behavior.
• Prefer readable logs and safe defaults.

Core behavior

• Read Modbus registers and publish to MQTT.
• Support per-entity refresh intervals (seconds or minutes).
• Use batching for contiguous Modbus reads.
• Publish only on change by default (configurable).
• Publish availability (LWT) and metrics.

Configuration rules

• src/config.yaml is the active config file.
• Validate config on startup (required fields, unique_id).
• Support state_topic override per entity.
• Support value_map for text mapping.
• Allow computed entities (input_type: computed).

Reliability

• Reconnect Modbus with exponential backoff.
• Backoff per entity after read errors.
• Keep MQTT connection stable and log failures.

Observability

• Log at INFO by default, allow DEBUG via config.
• Optional file logging via log_file.
• Metrics to <topic_prefix>/metrics.

Changes checklist

• Update README and CHANGELOG when behavior changes.
• Keep ASCII where possible (avoid accents in new files).
• Add minimal comments only when logic is not obvious.