Gage Langdon

Home automation

One button for the whole hi-fi

July 29, 2026

A single Zigbee button on the coffee table that boots a multi-component hi-fi system, switches inputs, and starts Spotify, simple enough for a guest to use.

The focal point of our social living room is a hi-fi stereo: an amplifier, a network streamer, and a turntable, all feeding one pair of speakers. We use it a lot, but actually turning it on was its own small project every time. Wake the amp, switch the streamer’s input from phono (for the turntable) to network (for Spotify), pull up Spotify on my phone or ask Alexa, and pick something to play. None of that is hard, but it’s four separate steps across three different interfaces, and it meant guests never touched it themselves; they’d just ask us to put music on.

Now there’s one button on the coffee table. Press: Spotify starts, shuffled, on the right input, at the right volume. Press again: pause. Hold: everything shuts off and the amp drops back into standby. Anyone in the room can run it, which was the actual point, not just saving myself a few taps.

This took an evening, and almost none of it was the automation.

The hardware

All of this runs through Home Assistant, an open source hub for home automation: it talks to Zigbee devices, gadgets on the network, and cloud services like Spotify, then runs whatever logic you give it. Mine is self-hosted on a Raspberry Pi, with a Zigbee USB adapter plugged in so it can hear the button.

The chain is: Spotify to the WiiM over the network, WiiM to the Marantz over an optical cable, Marantz to the speakers. (If you’re curious what’s on the other end: Focal Aria 948.)

What it does now

Flowchart of the button automation. A press branches into short, double, and long press. Short and double press pause or skip when music is playing; otherwise both run a nine step start sequence. Long press stops playback and puts the amp into standby.
The whole automation. Three triggers, one shared start sequence.

Starting volume depends on the time: 15 normally, 10 after 11pm. For scale on this amp: 5 is barely audible, 15 is dinner music, and 65 is loud enough to make out the lyrics from across the street through the glass wall.

The part that actually took the time

Powering the amp on and off. I assumed this was the trivial bit; it was the whole problem.

Home Assistant could see the Marantz, read what it was playing, change its input, set its volume. It could not turn it off. Meanwhile the HEOS app on my phone, same amp, same network, has a power button that works fine. Four options, in the order I tried them:

That’s what the phone app does: HEOS for the music, the old Denon protocol for power. Home Assistant only speaks the first one.

The custom bit

Home Assistant has a built-in telnet switch, but it’s YAML-only:

switch:
  - platform: telnet
    switches:
      marantz_power:
        name: Marantz Power
        resource: 10.0.0.200
        port: 23
        command_on: PWON
        command_off: PWSTANDBY
        timeout: 2

One deliberate omission: command_state, which would poll the amp to ask if it’s on. In standby the amp stays on the network and answers as if nothing changed, and a state that lies is worse than none. The automation checks whether music is playing instead.

Two bugs worth writing down

On using an AI assistant for this

I built the entire thing with Claude, working in Cowork mode against a completely blank Home Assistant setup. My part was physical: unbox the button, pull the plastic tab out of the battery compartment, and tell Claude what I wanted it to do.

From there Claude drove the browser itself. It opened Home Assistant’s UI, put the Zigbee radio into pairing mode, and discovered the button. It found the Marantz amp and configured it through the HEOS integration. It walked me through authenticating my Spotify account against Home Assistant so the automation could control playback directly.

The best part of the whole project: Claude probed the amp over the network and turned up an old forum post mentioning that sending a power-on command over telnet to port 23 would actually wake a Marantz amp on the local network. That’s not something the amp’s Home Assistant integration knows how to do, and it isn’t documented anywhere obvious; it took digging through old owner forum posts to find. Small thing, and exactly the kind of discovery you don’t expect a piece of software to go make on its own.

The prompts that worked described the outcome, not the steps:

use chrome to access home assistant. I want a new automation that runs on trigger. when triggered it should turn on the marantz amp and play spotify on the wiim.

Set volume on amp to 15 before playing music. If music is already playing on the wiim and the button is clicked, pause. If music is playing and double click, skip to next song. if amp is on and button hold, turn off wiim and amp.

And the one that unblocked everything, where I supplied the one fact it couldn’t know:

holding the button only mutes the marantz amp. in the heos app i can turn it off (enter standby); we want to do the same with our automation for power saving and to ensure the amp remains cool when not in use

It had already correctly concluded HEOS can’t do power: true, and a dead end. Knowing the phone app could was the clue that a second protocol existed.

It also said, after sending the standby command, that it couldn’t verify the result from where it sat and I should go look at the amp. Which is the right answer. The display was off.

Worth it?

We already used the stereo a lot; that was never the problem. An evening of work to cut four steps down to one press is worth it on its own, but the part I keep coming back to is the amp actually going to sleep when nobody’s listening instead of idling hot all night.