How do smart speakers control lighting and HVAC?
Smart speakers can only communicate with connected smart devices. First, you need to connect your smart device to the internet directly through your Wi-Fi router or through another hub that talks to the smart device with one language (Zigbee or Zwave protocol) and to your Wi-Fi router using another protocol. Next, synchronize this smart device to your smart speaker's list of such devices. Your speaker will then understand the list of traits your device can support, such as turn on, turn off, adjust temperature or dim.
Your smart speaker will handle speech variations that can trigger these traits. When you tell the voice assistant to turn up the thermostat or turn on a light, it will process this voice command and send a signal out onto the internet through your router which will be sent back to the smart device.
Some devices, such as lightbulbs, may need to be already turned on in order to work with voice control. If power to the bulb is switched off, it will not respond to a voice command. You can install a single smart wall switch to control power to lighting and other connected devices on a single circuit.