Brands like Shelly have very nice WIFI switches (with MQTT support), which allow you to control 230V devices easily from Node-RED:
I have some limitations regarding WIFI, so I was wondering if somebody has come across a similar wired solution? By which I mean such a switch with an RJ45 connector, where you can plugin a CAT cable to switch the device on/off via your LAN.
When I google for something like that, devices like this always popup in my results:
But that is an entirely different price range. To be honest I am quite suprised that companies like Shelly don't offer a decent affordable wired solution. But perhaps I am looking for the wrong keywords.
So if anybody has come across something alike, please share it here!
Certainly a few out there. But the cheapest I found was about £70 (that might be ex. VAT though). I think you might be better off either setting up a Zigbee network or a Wi-Fi mesh.
I am now wondering how such a manufacturer meeting is started:
Point 1 on our agenda for today: seems that a lot of poor people need a wifi controlled relay. So lets get started and make decent affordable devices for them, so we can make the world better.
Second point on the agenda. Seems that some other people want to have an rj45 connector on a switch. Oh dear, this must be the rich and famous. An rj45 connector, how spoiled can you be... Certainly professionals. So lets make an expensive range for them, and let them bleed.
I think that the need for ethernet connected relays didn’t come up as the niche for wired components was already filled by wired bus standards like knx which have been around since the early 90‘s and even earlier.
How so?
A "decent" wifi network at home is really important. For IoT stuff as well as e.g. peace with children (side note, it seems that Internet is more important than water for the youngest...)
And to answer more directly to your question, ethernet based relays can be DIYed. They won't come in a nice and small box though. An arduino based solution with a relay does the job.
But of course ethernet isn't just a connector. You need a controller and a network stack. It comes down to economies of scale I guess. When mobile phones took over the world, WiFi became ubiquitous and cheap. With the all-in-one controllers at well under a dollar in bulk, made by the 100's of millions, and no connectors needed. With ethernet, probably the connector costs more than the chipset these days and manufacturing with a connector is always more expensive than without.
As mentioned, there are plenty of raw boards out there - I'd bet that at least a few of them are actually OK, you might just need to buy a selection to see which are safe. Like the SONOFF units, as long as you run them well below their "rating", you shouldn't really have any issues.
Bart is, I know, like me, nervous about dealing with mains electricity. Rightly so. Though as long as you don't try to cram things in too close together and keep good separation between the low and high-voltage sides of any board, all should be good. There are plenty of outdoor enclosures and waterproof plugs (both mains and ethernet if needed).
Still won't be as cheap, I don't think, as Zigbee or Wi-Fi though by the time you've finished.
Arduino with a ENC28J60 Ethernet and relay Shield cost you are around €12 finished for the hardware.
Couple of evenings programming and you are up and running.
So the hardware without a relay shield is around €10.
You have also install some Cat-5 wires and have a switch with enough outlets.
An ESP8266 wifi module will cost you €0,81, no wires needed so everybody can install it.
That's most likely why wifi is more popular for Iot then wired networks.
Payload for Iot devices is very low and works very well with wifi, even if you have around 40 devices running.
Part of the reason industrial grade products are more expensive than consumer grade is that if, for example, it is rated at 16A then it will cope with that, and if there is some electrical interference on the leads then they are much less likely to get confused.
When I worked for a process controller manufacturer we had to test the kit using a 20kV spark generator playing all over the case and connections (to simulate static discharge) and it had to survive and only suffer temporary disturbance of the outputs, recovering when the sparks stop.
@Colin yeah I get that but also its SEIMENS so add another set of noughts to it lol
Have a lot of experience with there stuff, S7 not as good as some may think! Used it on some plant in California, for acid etching machine.
@BartButenaers have you looked into DALI?
i used that on aircraft evacuation trainers to simulate the lighting system, had led, fluorescent, and normal bulbs on it. Protocol isn't to difficult and its a 2 wire system, data over power! https://www.dali-alliance.org/
Morning guys,
Thanks for all feedback!
Will digg through it in more detail during the weekend!
At first sight the Shelly pro devices seem to be close to what I want.
It is a nice closed case (even din-rail), which makes it safer to work with at 230V.
But why the hell does even Shelly add that "Pro" postfix to the name, and then double/triple the price...
I hate it when companies do that
(side note, it seems that Internet is more important than water for the youngest...)
