Hi all,
I am on a sweet situation as I am planning my own home from the scratch. Because of this, I would have perfect opportunity to do a lot of hardwiring. However, as I have been trying to find hard wired sensors, it seems to be fairly difficult. For example door sensors, motions sensors, leak sensors, temperature and humidity sensors. Are you aware of some brands that would make hardwired zigbee or thread sensor products? In best case I would have one big transformer somewhere in my technical room where I have plenty of outputs for these sensors.
I am not sure why you would want the sensors “hard wired” and then also wireless (zigbee etc.). Either the power is NOT needed for the sensors to transmit their state (such as for a hard wired door or window sensor), or power required just to operate such as a motion sensor. If they are wired then you already have the state through the wire itself and don’t need any power - or could supply the power over POE… Let’s take for example a door or window sensor - open or closed. There are only two wires required from such a sensor, and no power even required. I think you are looking for in that case, a way to wire those two plain wires into HA. That can be done easily with a custom sensor you could buid with ESPhome or the like. If you are talking about a sensor that would need power to operate such as a motion sensor or the like, there may be POE versions so in that case you could get power to it and also get the sensor data back through the wire. A great rule of thumb is to always have all data and power through hard wiring wherever possible and try to avoid less reliable over the air (as well as batteries) so to speak. But if you are talking about powering a motion sensor and to have it also supply the sensor data instead over the air, that is a different animal. Ideally if building a house from scratch I would supply both ethernet (with POE - and actually also regular house power to everywhere so you have the best options for both for future technology :-)… If everything possible is hard wired and only power is used only when absolutely necessary, then you can have the option of some non-battery powered sensors working even when the power to your home has been cut … So you need to be more granular or specific in your question/s? Can you give a specific example or use case (as every one may be unique)…?
Protocols like Zigbee and Thread are based on radio, however there are several wired networks out there like KNX (big in Europe), MODbus and Loxone to name but a few. Several are focused on commercial building automation and tend to be distributed (e.g. PIR links to a light directly via initial programming) rather than classic HASS (PIR, HASS, automation, light).
I’d suggest a look at Automated Home, as they have self-built a couple of times in Northern Ireland:
Basically, put everything in ducts. You’ll be ripping out all the kit in 20-30 years for the latest shiny…
Hi, thanks for guiding towards POE, that seems fairly interesting! Especially for security cameras, maybe also some sensors. With a quick glance they seem fairly expensive though. Especially for some simple sensors such as door open/close sensor POE prices seems pretty overkill. I was wondering if a cheap non-smart wired door sensor with some smart relay would work?
My use case would be more or less that I would love to avoid battery as a power where ever I can, and hardwire as much as possible I can. And right now is the perfect time for that kind of planning as the structural planning, electricity and hvac planning is about to start. So I try to plan ahead where I need ethernet output, where I need some low-voltage outputs, where ordinary schukos and so on. Now I can easily get things hidden inside the walls.
Hi, this is interesting indeed! I somehow had already forgotten the whole KNX. Would KNX sensors work with Home Assistant together with other devices such as zigbee devices? Let’s say I would have KNX based sensors and some zigbee based smart wall switch powering the lights?
Yes, you would just have to do some automations - just like any other domains you’d want to connect via HA.
For a Knx guy this sound unintuitive Have a look into Knx smart switches. You can decide / reassign later what their actions are. Lights are controlled by actuators (often Multichannel) - not directly connected to any switches. Some use DALI with decentralized drivers and Knx gateways because they are cheaper and available in CC (whereas Knx currently mainly focuses on CV or 230V dimmers).
The strength of HASS is the ability to mix different platforms into one system, so yes, in principle, KNX could trigger Zigbee.
Just because you can, doesn’t mean you should though as this adds complexity, cost, points of failure, etc. Pick one platform and architect around that, adding others to fill gaps.
If you go to the expense of cabling for KNX ceiling PIRs, it would be surprising not to cable for KNX lighting switches which would be barely meters away.
If you really want a specific designer switch for aesthetics, install a dumb contact with a sensor module behind it. Mains controls could well be relay/ dimmer modules mounted centrally in a distribution board, wired radially. Clearly there is a tradeoff between mains cable and network cable length / cost.
- and actually also regular house power to everywhere so you have the best options for both for future technology :-)… If everything possible is hard wired and only power is used only when absolutely necessary, then you can have the option of some non-battery powered sensors working even when the power to your home has been cut 
this post!
Have a look into Knx smart switches. You can decide / reassign later what their actions are. Lights are controlled by actuators (often Multichannel) - not directly connected to any switches. Some use DALI with decentralized drivers and Knx gateways because they are cheaper and available in CC (whereas Knx currently mainly focuses on CV or 230V dimmers).