MQTT lets compatible systems like Home Assistant monitor and control your RV alongside everything else in your smart home. Most people can leave this off, RVAltCtrl works great entirely on its own, but if you already run Home Assistant or another MQTT-based setup, this connects the two. Manage it from Settings → MQTT.
Fields
- Enable MQTT: turns the connection on. Nothing below matters until this is checked.
- Broker Host: the address of your MQTT broker, an IP address (e.g.
192.168.1.50) or a hostname (e.g.broker.example.com). - Port: your broker's MQTT port. Defaults to 1883 (plain) or 8883 (TLS) depending on the TLS toggle below, but you can set it to whatever your broker actually uses.
- Use TLS: encrypts the connection to your broker. See TLS (Experimental) below before turning this on.
- Username / Password: optional, leave both blank for an anonymous connection if your broker allows it.
- Client ID: optional. RVAltCtrl generates one for you automatically if left blank; the greyed-out placeholder text shows what it would use.
- Base Topic: optional. Prefixes every topic RVAltCtrl publishes or subscribes to, in case you need to namespace it alongside other devices on the same broker. Like Client ID, leaving it blank shows the auto-generated default as a placeholder.
- Publish Home Assistant Discovery: see the next section.
Unlike Wireless Sensors's Enable BTLE switch, which takes effect the moment you tap it, nothing on this page takes effect until you press Save, including the Enable MQTT switch at the top. Flipping a switch here just changes what's about to be saved; your device keeps using its previous settings until you actually save.
Home Assistant Discovery
Turning on Publish Home Assistant Discovery tells RVAltCtrl to publish Home Assistant MQTT discovery messages alongside its regular state and command topics. Home Assistant picks these up automatically. Every control RVAltCtrl knows about, lights, switches, climate, tanks, battery, and more, shows up as its own entity in Home Assistant with no manual entity configuration on your end. From there, they're just normal Home Assistant entities: add them to any dashboard, group them into any room or area, and arrange them wherever you'd like in your own layout, exactly like any other device in your smart home.
It's worth giving your RV a name first, from Settings → RV Name on the device, since that name is what shows up as the device name in Home Assistant.
Discovery messages are republished automatically every time RVAltCtrl reconnects to your broker. There's also a Publish Now button on the MQTT page for whenever you want to force a refresh without waiting for a reconnect, useful right after you rename something, for example.
You don't need Home Assistant to get value from MQTT. Turn MQTT on by itself, without Discovery, and RVAltCtrl still publishes the same state and command topics to your broker for any other MQTT-based system, script, or dashboard to use. Discovery is purely a Home Assistant convenience layered on top.
TLS (Experimental)
We recommend running MQTT without TLS, against your own private broker, one on your home network or your RV's own network, not exposed to the public. That keeps things simple and avoids the issues below entirely.
TLS support exists and can be turned on, but it's still experimental. Handling TLS certificates takes a meaningful amount of RAM, more than the RVAltCtrl device comfortably has free while running everything else it does. Because memory is this tight with TLS enabled, you may need to turn off Bluetooth (Wireless Sensors) if you're also using TLS for MQTT, since both compete for the same limited memory. If you don't need Bluetooth sensors, this may be less of a concern; if you do, consider whether a private broker without TLS would serve you just as well.