Which module does what: the overview

Updated 16 October 2026SmartKnob

Camper Jarvis consists of the SmartKnob and modules that each take on one area. Some modules switch power to your appliances, others talk to a device through its own interface or read sensors. This overview shows which module does what, so you can see quickly what your build really needs.

At a glance

Module What it does Switches power Measures consumption Wired push buttons 230V
Ampy Switches, protects and measures 12V and 24V appliances, dims light up to 5A per output Yes, 6 outputs Yes Yes No
Switchy Switches 230V appliances and 12V or 24V appliances, checks shore power Yes, 4 × 230V and 4 × DC No No Yes
Lighty Lighting with fine, flicker-free dimming, white from warm to cool and colour Yes, 5 channels Yes Yes No
Heaty Controls your heater through its interface No No No No
Thermy Controls air conditioning and fridge through their interface No No No No
Volty Pro Reads your energy system, switches the inverter on and off No Battery, solar, charging No No
Fluidy Pro Tank levels, temperature, water pressure and leaks No No No No

The SmartKnob is the centre of the system. You operate everything on it and in the dashboard on your phone, tablet or laptop. It also has its own sensors for presence, brightness, temperature, humidity, air pressure and tilt.

Two kinds of modules

Ampy, Switchy and Lighty switch power. Your appliances are connected to them, and they switch the supply on and off. Ampy and Lighty also measure what each output draws and protect it with an electronic fuse.

Heaty, Thermy, Volty Pro and Fluidy Pro do not switch power. They talk to a device through its interface or read sensors. Heaty, for example, tells your heater which temperature to heat to, instead of cutting its power.

Typical cases

  • Light: For one or two white lights that you switch and dim a little, Ampy is enough. For very fine dimming down to 0.1%, white from warm to cool, colour or a gentle sunrise, use Lighty.
  • Water pump, fan, fridge on 12V: Ampy. You also see what each appliance draws and set its fuse.
  • Fridge with CI-Bus: Thermy controls it through its interface.
  • Diesel heater: always Heaty. Do not switch a heater on and off through its power supply. After switching off it needs an afterrun to cool the burner, and that afterrun is missing if its power is simply cut.
  • 230V sockets or a boiler heating element on 230V: Switchy, up to 10A per channel. Each 230V channel needs its own B10 circuit breaker.
  • Pop-top roof or lift bed with a 12V motor: Ampy over two outputs. The direction lock sits right inside the device, so both directions are never on at the same time.
  • Inverter: switched on and off through Volty Pro, either via its data interface (for example Victron MultiPlus) or via the remote output.
  • Check shore power: Switchy detects a swapped phase and neutral and a missing earth. If the earth is missing, it switches all 230V channels off at once.

Push buttons and switches

Wired wall push buttons and switches are connected directly to Ampy and Lighty. They switch there directly, even if the SmartKnob is not there. Switchy has no inputs for wired push buttons.

With wireless push buttons from Häfele Connect Mesh you can switch any device where on and off makes sense, including the channels on Switchy. They need the SmartKnob, also during normal operation. Wireless push buttons from Shelly will follow later.

Automatic switching

The radar sensor in the SmartKnob detects whether someone is in the vehicle. You can link your devices to presence, for example light, water pump or inverter. When you leave the vehicle, they switch off after an afterrun time you set yourself. When you come back, everything returns to how it was.

Presence and time of day can be combined. An example with a fan: it runs while someone is in the vehicle. Between 8am and 8pm it keeps running for 12 hours after you leave, from 8pm to 8am only for 2 minutes. Heaters have their own time schedule built in, so warming up in the morning works directly through Heaty.

Start small

You only take the modules you need, and you can add more at any time. A new module pairs with the SmartKnob in seconds, with no new cables to the SmartKnob. Only plan the areas where you would otherwise have to rewire later: the LED strips for Lighty and the fuse level with Ampy.

More on the system as a whole in How Camper Jarvis is built.

More on this: Camper van smart home: how to retrofit your motorhome.

Related questions

How do I connect a new module to the SmartKnob?

Pairing practically takes care of itself. You start it on the SmartKnob or in the dashboard and then power up the module. An LED and a sound on the SmartKnob confirm that the connection is up. That is all there is to it: no cable to the SmartKnob, no configuration, no searching for networks. The only thing that matters is that your SmartKnob is already running, because the modules always connect to it. With Lighty: right after pairing, its wall push buttons stop responding. Create a light widget for each light in the dashboard and switch on "Push button" in it, then they switch again.

Can I use several modules at the same time?

Yes, up to 20 modules at the same time, in any combination. That is enough for almost any camper conversion, from a compact panel van to a fully equipped motorhome. If you want to add several modules one after the other, the SmartKnob stays ready to receive for a short while after each successful pairing. You simply power up the next module.

What is the difference between AP and STA mode?

The two modes only decide which Wi-Fi network you use to open your dashboard on your phone or tablet. They have no effect on your modules. • AP mode: the SmartKnob opens its own Wi-Fi network and you connect your phone or tablet directly to it. You need no router and no internet, ideal when you are parked off-grid. • STA mode: the SmartKnob joins your existing Wi-Fi network, for example your camper router or your phone's hotspot. That is handy if you want internet access at the same time, for instance for online updates. You can switch between the two at any time.

What happens if my Wi-Fi drops out?

You are still never locked out. If the SmartKnob loses the connection to your Wi-Fi network, because the router is off, you have moved to another pitch or you are simply out of range, it automatically opens its own Wi-Fi network again. You can then reach the dashboard directly through it straight away. As soon as your usual network is back, it reconnects to it by itself. You do not have to do a thing.

What happens if the SmartKnob fails?

Ampy and Lighty keep their settings and carry on working. You simply keep switching and dimming lights and appliances at the wall switch, fuses and voltage protection stay active, and the outputs stay as they are. The display, dashboard, scenes, automations, the double tap for all lights and the wireless push buttons pause. This is a fallback, not a permanent state: without the SmartKnob you cannot change settings such as fuse values, and dimming only works with push buttons, not with switches. The one exception: an Ampy output set up as a heating element switches itself off after 10 minutes for safety, so that no boiler keeps heating unattended. We are also working on a backup function where a module takes over the dashboard, so that the whole system can still be operated from your phone and tablet.

What do I need to watch out for when mounting the SmartKnob?

The wall surface under the mounting plate must be flat: no more than 0.5mm of unevenness across the whole area of the mounting plate. If the wall is bent, curved or warped, the SmartKnob will not click in cleanly. Check the surface with a straight edge before screwing the plate on. Double-sided tape on the back of the mounting plate gives extra hold.

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