Non-internet-connected "smart" thermostat/thermometers

Question

I am aware that there are many emerging standards and products all focused on making my internet-connected home accessible from anywhere. I am exclusively interested in a solution where there is no internet connectivity - though there is a wired and wireless LAN and a range of computers/tablets - etc.

I am keen to establish a smarter control of heating - and to monitor the effects by collecting data that I can later analyse (on Linux by writing scripts etc.) I'd like to be able to implement an arbitrary heating regime driven by a range of sensors. I'd be happy if this were through a polished GUI - or if I were to roll-my-own using an API to low-level interactions with the sensors and thermostat. I would not be happy if (at any stage) any device at the house needed to be connected to the internet.

I am struggling as I only seem to be able to find advertisements for the-latest-and-greatest cloud-controlled systems. Is it possible to buy basic 'smart' thermostats and sensors that would work (directly) on a non-internet-connected network - ideally where I could control them from a standard Linux server? If so, what should I search for? Are there any open standards that I could choose to minimise the effort required to establish programmatic access to the features of the devices from my private LAN?

Answer 1

You are basically asking for an open IoT "edge" solution. You could try something like Eclipse Kura or Project Flogo which can run on popular open boards, and you'll have full control over how much do you want ( or not ) to send to the cloud.

For getting those to talk to off-the-shelf consumer products will be a hacking challenge in every case though. Best solution for that might actually be using Apple HomeKit compatible products and run open-source Homebridge on your "edge gateway" for controlling the devices.

There are a few other ways of doing it as well, for devices that speak somewhat standard local protocols, such as Zigbee or Z-Wave. You basically have to set up a Zigbee or Z-Wave gateway function on some embedded Linux board ( BeagleBoard, BeagleBone, Raspberry Pi ) and get your devices to connect to it. To ease this, there are software stacks like Mozilla IoT gateway or OpenHAB or Domoticz to make this easier.

Answer 2

A short answer to your long question is as following:

1. You can completely avoid internet connection but you will need to setup SDK/certificates for security and identity purpose (you can use your laptop or other pc)
2. You can use AWS, AWS greengrass or Azure sdks to communicate or device identification. Using these sdks would make your life easy to communicate with sensors easily. Or you can also use completely ad-hoc own code using python or nodejs for sensor data communication.
3. Use any local/LAN database connectivity through REST API in your code to store data in database.
4. You will need to create own monitoring tool (may be some ready-made tools also available on internet) to fetch data from local database for analysis or even live streaming of incoming sensor data for monitoring.

What you questioned is possible however timely system or security updates/patching will go outdated without internet.