Sensors and smart plugs can control your home automatically.

Sensors, not voice is the future of the Smart Home

Alex Cox
5 min readNov 14, 2019


Imagine for a moment that you want to turn on a light in your super modern smart home? You have an Alexa enabled light switch. You say “Alex turn on the living room light.”

The light just turns on. Feels like magic, right?

Well. At least a few years ago it did. Now we’re at a point where voice control is taken for granted and we’re looking for the next innovation in home automation and control.

But that innovation is already here thanks to sensors.

With low power cheap sensors we are making any device not only smart, but intelligent. Look at the Nest. Its intelligence is thanks to 2 core things.

  1. A temperature sensor
  2. It’s backend watching the temperature readings and learning when to adjust your home’s temperature based on how you control the device and if you’re home

Since the Nest came out we haven’t really seen any other devices that can just do their thing without your intervention. Most devices still require a lot of turning on / off and babying to get it to work.

When it’s dark in a room and you’re in the room. How long does it stay dark? Usually just long enough for you to flip the light switch.

An infrared sensor can see when you walk into a room today. A light sensor can detect how bright or dim a room is. Combine that with a smart light switch and you’ve got yourself an autonomous light switch.

This same simple example with a light switch can be expanded to nearly every appliance in your house. When no one is in your home, the home should essentially turn off. The heat or cooling should turn down, any fans should turn off, the inside lights should turn off, and the house goes into a sort of hibernation mode. Then, when someone leaves work or school to come home or enters the house, the home should turn everything back on in the rooms the people are in.

With sensors placed strategically around the house and an app on the home dweller’s phone, their location inside the house and outside that house can be used to inform what is turned on and off whether that’s lights, fans, TVs, cable boxes, or the HVAC. Everything can be controlled only for when it’s actually needed. On top of saving electricity and money, sensors can help the people in the home stay healthy and productive.

With sound, light, and temperature sensors in the bedroom, the quality of your sleep environment can be tracked and changes can be made automatically. For instance, if there’s traffic noise at 2 am when the bars let out, your room has a bit too much blue light, or the bedroom temperature drops below 60° while you sleep. With local sensors, these abnormalities can be detected and fixed without you even having to wake up. Your speakers could start playing white noise to smooth out the erratic traffic noise, the furnace would know to turn on to keep the bedrooms a comfortable temperature, and lights could be automatically turned off if they were left on or the homeowner could be told that it’s a bit bright in their room for a good night’s rest.

These sensors all exist today, but most people do not have more than one or two smart gadgets, so there’s nothing for them to control. With cheaper smart plugs, however, anything can become smart. Imagine having a CO2 sensor in your living room and a typical old fan plugged into a smart plug. Now, when the CO2 is high, the fan can automatically turn on to circulate the air around the home. Or, when the air quality is poor, having any old $80 amazon air purifier automatically knows to turn on.

When you combine lots of sensors into one device such as Temperature, humidity, sound, light, infrared, CO2, chemicals, air quality, and air pressure you can build a more comprehensive view of the home and the environment inside that home. It’s like having another person there to turn things on and off based on how you’re feeling. Putting these sensors around the home can inform your HVAC when you might need some fresh air in the kitchen after a failed cooking experiment while also turning on just the kitchen air purifier to get rid of the smoke. Having these sensors in more places and giving them the smart plugs or smart thermostats to control means a fully automated home, today.

But the sensors alone are not what make this system innovative, it’s what the backend can do with those sensor readings. Thanks to the smarts in the cloud, when you burn something in the kitchen a comprehensive response can be triggered. From fresh air piped in via the HVAC system, to the kitchen’s air purifier turning on, all the way to an electric air freshener in the corner turning on. This sounds like science fiction, but that whole system would cost about $200 today with about $150 coming from the smart thermostat and $50 coming from smart plugs. The only missing piece is a sensor box with the backend intelligence to integrate and coordinate these other devices.

As the cost of sensors continues to come down, I think we’ll start seeing Amazon and Google begin to integrate more and more sensors beyond just their microphones to better control your home.

It’s just a matter of time before you can stop ordering your Alexa around and start enjoying a home where everything is done automatically.



Alex Cox

Product Manager and designer writing about ideas. Living and working in SF. See more of my projects at