Windrow
Windrow ("Windrow") is a separate sibling repo, not code that lives in this one — it bridges BACnet (and Modbus) devices to MQTT so Baler never has to speak a building-automation protocol directly.
Why it exists
Haxall (SkyFoundry's open-source BIoT framework) ships open connectors for Modbus, MQTT, SQL, oBIX, and more, but not BACnet. Windrow fills that gap: it speaks BACnet directly (via BACpypes3, BSD-licensed) and publishes readings to plain MQTT — no Fantom code required.
How it reaches Baler
Windrow and Baler share nothing but an MQTT broker and a frozen wire contract (Adding a New Source):
- Topic:
f"{topic_prefix}/{point}", e.g.fbf/mock-ahu-1/analogValue,1. - Payload: JSON
{"point": <str>, "value": <int|float|str|bool|null>, "ts": <unix epoch float>}, published retained viawindrow.mqtt_sink.publish_reading(). - Tags (Haystack markers, equipment refs, units) ride the same helper
under a
<point>/tagstopic, published once at startup rather than per reading. Baler'smqtt_listener.pystrips the/tagssuffix to recover the point's real topic and routes toingest_tags()instead ofingest_reading()— samepoint_urieither way.
Baler's side of this needs no Windrow-specific code at all:
mqtt_listener.py already subscribes to fbf/# and treats every message
identically regardless of which protocol produced it. See Adding a Data
Source for the push-vs-pull decision this all
comes from — Windrow is the answer for anything push/protocol-native
(BACnet, Modbus, a native MQTT device); a periodic REST/HTTP source (like
Haystack Puller) belongs in this repo instead.
Status
Early scaffold, per Windrow's own README — a mock BACnet device/site generator and discovery API exist and are exercised in Windrow's own test suite, but treat it as young, evolving code, not a hardened production bridge.