AS the topic states, im curious how others are powering their smart devices?
Im not referring to smart relays or smart plugs that have meanwell power supplies in them. I have a few Wemos D1 mini’s floating around doing odd jobs, and find myself having cell phone chargers in way too many places. Some even a little out of place and probably wouldnt pass a decent COC inspection.
Is this a question about backup power for these devices?
I have a Wemos D1 Pro which runs my geyser temperature sensore - which I specifically bought for the idea of running it off a normal 5 (or 12v, can’t remember) power brick.
Other than that I have 1 Sonoff SV for the dry-contact relays which is rigged to run on a USB power supply. The other SonoffSV is powered from the gate motor’s battery, and for the rest I rely on Sonoffs / Shelly’s with the power supplies.
I did have a Pi running my Home Assistant instance, running off a CCTV power supply and 2x 7Ah batteries. I hadn’t put the batteries in case or anything - it was just standing on a bookcase. At some point the cat jumped on, lost her grip, grabbed onto the wires connecting the batteries, pulled the whole setup down on top of my wife’s Macbook Pro and broke the screen. Lesson learned…
Nope, as stated, how are you powering yours.
Now I have a similar setup to @ebendl my d1 mini that measures gesyer temp is on a cellphone charger, the plug is fed on the geyser circuit, fitted after the isolator, so it is isolated with the geyser if need be. However, I dont think this is the best solution, and I doubt it would be compliant for a COC.if I ever need an updated one.
My D1 Pro runs in my study, plugged into a wall plug. I repurposed the original analog RTC temperature sensor (came with like a 20m cable) that the geyser came with and just moved that to a different room in my house.
If I have a 5V application, then I will use the D1 mini directly powered by USB (from PC or USB PSU), but if it needs to run from 220V then I try to use a Sonoff for that if I can. But it depend on the requirement and if I can get away with only 1-2 pin(s) that the Sonoff have available.
I’m always disassembling old electronics (DVDs, Radios, Decoders, anything with an LED power light 
) and keeping the PSU part of the circuit. That is mostly 220V AC to 12V DC, and then you can just add a R20 buck converter to get to your 5V PSU.
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I’m in the same boat as many of you other guys. I tend to use old cell phone chargers to power the devices, and I specifically aim for things with onboard 5V->3.3V regulators (such as the D1 mini).
I have one device that needed 12V (the Askari alarm interface, yes I have my beams wired into HomeAssistant), so in this case I used a Wemos D1 (non-mini) which can be powered from 12V. And then I bought a 12V SMPS from Takealot, so in essence it is no different to the other setups: It has a wall wart.
I bought one of these to directly power a project where I want it to be a little neater, but the project was never finished.
I have quite a few ESP boards in my home automation, I don’t like running them with a cellphone charger, my thinking has always been that they aren’t really designed to power a constant load, having said that they will probably work fine and its just be being a little over the top.
I have a lot of 12V power supplies from routers etc… so I generally use those with an adjustable buck converter, a plus with this method is you can fine tune the voltage and make sure you’re getting exact voltage regardless of cable length.
These are cheap, around R25 if I recall
I used one of those for a project, and it “blew up” this week after working flawlessly for more than a year. This event is actually what sparked my question. as my workaround was to use yet another cellphone charger in the roof, and im thinking I should really try and avoid the concept.
Maybe then just buy a purpose built 5V DC power supply like this:
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Can I interest you in a low voltage DC supply reticulation in your house. I can ask my confidante @mjmacleod to contribute his expertise as well…
Problem is most these smart devices take low voltage which is a pain, more things should run on PoE/48v… But anyway.
Run PoE everywhere and buy a bunch of these https://www.takealot.com/tp-link-poe-splitter/PLID28719963 (or similar) for your non 48V devices.
Costs a little bit more than the solutions above (probably not that much more if you shop around and get them in bulk) but it will last, and the PoE setup is at least forward compatible with all the future fancy stuff like PoE lighting etc. that everyone is eventually going to realise they want.
If you’re powering a lot of things that are close together, split out from the PoE and use a larger converter and then power them all from that one converter…
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Thanks @mjmacleod
I never considered POE. It helps that I have a 24 port cisco switch, and only use 6 of the ports.
I might look into this avenue.
If you want to just buy stuff that works, a cheap POE switch will work wonders, and you get stepdown adapters for 12V, 5V, 9V, etc. Pay attention to the power rating though, you usually can’t get max watts out of more than 3 or 4 ports, even in a large switch.
If you’re in for a bit more DIY, or if you’ll never use the E part of POE, look at 24V camera / alarm supplies. Most have a space for a backup battery and at 24V your wiring can be ripcord. Then use those stepdown modules where you need them.
Definitely rather do that than wire 230V around in the roof by yourself.
With 95% of ripcord you can currently buy in the country being CCA (copper clad aluminium), you should probably verify the voltage drop and losses you expect. Last time I ran the numbers it looked like a much better idea to have the power source near the endpoint (like a DC ups).
That’s disappointing. Same thing is happening with network cable: POE doesn’t work properly over CCA either, so you need to make sure that’s not what you’re getting, and it’s becoming more and more difficult.
Must be why the wires in the new roll always breaks when using a cable stripper. Back to doing it by hand an teeth again.
Amazing! I was going to sing the praises of network cables and how much of it is simply thrown away. (Go have a look in the waste dept. of a large business/es or casino and you will find coils of the stuff. I gave up collecting it unless it had moulded plugs. Then I was only interested in long pre assembled cables, and so on…)
PoE doesn’t have to comply with the standard 24/48V. What I have found useful is to power the WiFi with 12V (typically) over CATx cable.
You need the LAN cable anyway and this allows you to install the WiFi in a convenient location for better coverage
No power is required at that point and if you have backed up your ONT then the WiFi will also be backed up during power outages.
Sure you can run any voltage down it, but its nice to be on the standard, especially if you want to later plug various standard devices in as well, and 48v is better for long runs…
But yes there are cases where just running 12v or 24v down it makes sense (if all your stuff is 12v or 24v).
Victron has a very nice range of DC convertors (orion tr DC-DC converters - Victron Energy) that you could use to drop from 48v to 24v or 12v and then feed your devices from PoE over that and unlike these smaller individual buck convertors will likely last almost forever.
I’m using both a “victron Tr 48|24 - 12” and a “victron Tr 48|12-9” here, both already multiple years old.