Request: Alternatives to the Raspberry Pi?
I will shortly have need for a small, low power (power as in watts, not compute power) system for always-on Home Assistant use. However, Raspberry Pis are out of stock everywhere and while they can be had for extortionate prices on various auction/marketplace sites, I'm not sure I want to spend a load of money on something which might not even be what it claims to be.
Home Assistant suggest Odroid which I'd probably go for the C4 edition but it's relatively expensive (I need to add an MMC and a psu and various other things to the listed main board price)
Any suggestions? The Asus Tinkerboard looks overkill and is very expensive. It needs to be capable of running a standard Linux distro, ideally Home Assistant's own OS. Low power consumption is a definite, 2-3W at idle is probably the maximum I'd be happy with. Wifi is a bonus although not required right now - but the ability to add it if needed is essential. Some amount of expansion capability would be good if I want to add hardware sensors or bluetooth or a Zigbee transceiver or whatever. It needs some reasonably amount of compute grunt I assume but I don't think HA is all that hungry for number crunching power. The machine will more than likely be headless at first but a little bit of GPU and graphical IO would be handy if I want to stick a display on it in the future, which I might want to.
Any ideas? Oh, and also must be easily available in/to the UK.
Relevant video just released by Linus Tech Tips:
https://youtu.be/uJvCVw1yONQ
But in my experience, Raspberry Pi has the Raspberry Pi community around it, and I'm not sure there is a drop in replacement that has a comparable community or enough overlap that you can ask for assistance and reliably get anything helpful.
So, I'll start with my review for the Raspberry Pi itself for Home Assistant, then work from there. I have the 3B+ and a 4GB 4.
It honestly works very well, even on the low-powered 3. However, I am using a separate VeraHub that does the heavy lifting for Zwave and Zigbee, HomeAssistant is for automation and UI only. When I last used Home Assistant on a Pi with a Zwave dongle, things got pretty laggy once I had more than a few devices. Switching to an x86 Docker image eliminated all the problems. So the answer I tentatively give is "ARM is great until it isn't."
The weakest part of the Pi is I/O. Especially before the 4, USB and network throughput was iffy. SD cards are also slow finicky things compared to a regular hard drive.
With that out of the way...my preference is an old laptop for running HomeAssistant. Built in battery backup, already has bluetooth and wireless. While you're not gonna bottom out at 2-3W, you'll also spend a lot more time idling. I should really take some time to study the metrics in more detail. To get a Pi running up from scratch, it'd cost me easily $50, between board, power supply, SD card.
I can get a free older laptop, there's dozens to choose from in a 10 mile radius. Even if it runs at 50W, that'd still be 2 years of runtime for less than paying for a pi, even at my high electricity costs.
Another great alternative if you can handle some finickiness is old cellphones. I got postmarketOS running on a Galaxy S5, which idled around your 3W goal. It performed as well or better than the pi, and for my use case (HomeAssistant and Vaultwarden) it worked quite well. Just be sure to take regular backups.
I second the old laptop suggestion. To add on to it if you don’t have one already you should go to eBay and buy a broken one to get a much better deal. After all, who cares if the screen or hinge is broken if you aren’t going to use them anyways.
The other reason I discounted the idea of a broken laptop is that I may well end up building this system into a nice monitor device which can sit on a shelf and display nice graphs about how power is being used in the house, which a laptop is rather less suited for, although not impossible. A SBC is much easier to shoehorn into a little wooden box though.
You might be surprised. The last few laptops I opened had the logic board only take about 2/3rds of the chassis at maximum; some only took about 1/4 the space. And of course if you buy one with a working screen you have an extremely nice display ready and working for you whenever you want it to.
As @whbboyd mentioned, most laptops don't use nearly that much power most of the time; those are peak ratings which describe the maximum they can draw when it's doing heavy work. While Home Assistant isn't the most lightweight application it's peanuts compared to the kinds of programs that these computers would typically be running.
More than anything the primary advantage is that you'll have more overhead; Not only will it take much longer to before you need to replace it because it doesn't do what you need, but you'll be able to use that same device if you want to run any other servers in the future. It's a much better long term investment.
I did consider an old laptop but sadly ~50W idle is not affordable for me. That's about 40% additional power use over my house's average base load and an extra ~£15/month at UK prices (45p/KWh). Even at half that power consumption an Odroid+MMC still pays back in less than a year. Admittedly the reason I'm setting up HA at all is to control and monitor my solar panels and battery which are being installed soon, but even so. I could be selling that power for profit!
I don't have a lot of devices right now and I think all of them are going to be managed via JSON over http rather than Zigbee/Zwave. That wouldn't have been my first choice but it does make the IO straightforward at least. But thanks for letting me know about ARM lagginess with lots of Things, that is helpful.
50W is wildly improbable, FWIW. Unless the laptop is actually broken somehow, I would plan for an idle power usage of closer to 5W-10W. (This completely arbitrary source suggests an average idle of ~6W.) Peak draw at the wall could be up to the max rating of the power supply (often 65W or 100W), but a typical homeserver is idle >90% of the time.
Ah, that makes more sense. I've never really thought about laptop power use, which is a bit of a miss on my part considering I wander around the house with a power meter looking for watts to save on anything with a plug..
5-10W is still quite a bit more power than a little SBC at <3W, but on the other hand using a laptop that might otherwise be going to waste does represent energy savings in other ways.
By the way, there is one thing that I forgot to mention in my earlier comment regarding power consumption.
One of the most power hungry peripherals on any computer is typically going to be the screen. LCD panels can draw a lot of power because they have to have a bright light shining through them in order to see them properly. @whbboyd's article gives two numbers, one for "short idle" and "long idle", and while it doesn't actually describe the difference I'm pretty sure that they are talking about the point in which the operating system would shut off the display. So you're actually probably going to be looking at a very similar amount of draw to that RPi until you decide you want to use that display.
That being said, every computer is different and your configuration will also affect it, so YMMV.
Yeah, LCDs, especially high-res ones, really eat power. My last little Pi-powered project used an eink display, which means for 59.5 minutes out of the hour it draws no power at all, then spends 30 seconds refreshing - and yeah, 0.03fps is a framerate to be reckoned with, but I do have it running on the slow side to gain clarity..
The output of Home Assistant that I'm interested in will, I hope, have limited requirement for rapid updates so I'll probably use eInk again if I can, or perhaps a dot-segment display or LED matrix for more realtimey stuff. If I want to dive deep into the data and smoosh it about I can use a web browser on my PC to do that. I'm really interested in ambient information systems so the more I think about it, the less useful an LCD is on this machine at all. I'm currently wondering about using some RGB LEDs to wash a wall with colour that communicates power status at a glance. Then I got a bit distracted trying to think about using a bubble tube which can communicate power level by bubble density and status by colour and really that's just not practical but it might be fun.
What I'll do is run the system for a bit without it's own output system(s) and see what information I need out of it and try to find an interesting and low-power way to communicate that to me and the rest of the people in the house. At least 60% of whom are not interested in graphs or numbers.
This is correct. I was putting a hyperbolic high rather than an actual idle.
I am a big fan of thin clients for this application. Most of them do sit a bit higher in power usage, but the wyse 3040 looks like it runs at 3W idle.
I have 4 raspberry pis I'm not using if you (and others) want them. They're Pi 4s with 4GB of RAM, micro SD card and PoE hat included.
I've been interested in running norns for a super long time but haven't since my pi is too old. Can I buy one off of you?
I was going to give them away for free.
Giveaway thread
Oh wow thanks so much! Will go there
I have many RPis and also an Odroid C2. The latter runs really reliably but the eMMC is really annoying, as you already mentioned. Then I got tired of the ARM processors and fully switched to a DeskMini home server. Definitely not the cheapest alternative, but with Proxmox the most versatile by far :) Since I got that, I barely touched my RPis and migrated all kinds of containers to my server. Only HA and a small discord bot runs on my RPi4 for now.
Years ago, I used to have a big (relatively) home server which did all my... well, home serving. HTPC, NAS, webserver, general mucking about, torrents, etc. etc. But over the years I've ended up with more little dedicated systems, each running at a few watts each rather than a big machine which probably draws the same amount of power.
Yeah, I can see that being nice, too. But with Proxmox you can create a VM on your home server within minutes and this way everything has its own little system, too. Really useful! Also supports LXC, which is nice (but I don't have any experience yet with it).
Having had the same question, a friend suggested Libre Board to me. I'm not sure if it meets all your needs - I'm not sure if it meets all my needs - but having asked the same question yesterday and received this as an answer, I thought I'd at least throw it your way, and wish you good luck, and then maybe see if it meets your needs, which seem like they exceed my needs, it's not really a selfish answer, honestly.
Yeah, those have come up... I'm not entirely sure they meet my requirements, quite. But they might. I need to spend a little more time with their spec sheets I think. I love their attitude though, would be nice to support the project if possible.
Take a look at some of the videos from Explaining Computers on YouTube. He does a lot of reviews of single board computers, so he could probably give you a good place to start.
I don't know what time scale you're working with, but it might be possible for you to wait for a Raspberry Pi as they expect to be back in stock within a few months (sorry, I know this isn't really what you asked for.)
I'd like to have a system running by the end of the month, ideally. But it wouldn't be a disaster if I waited a bit longer.
UK? Stick some alerts in an RSS reader with rpilocator and keep an eye on it. I waited a year for a 3B+ (specific use case) but managed to get hold of a 4 within about a week of checking.
There's plenty of Pi alternative SBCs but software support isn't nearly as good so you could come across all sorts of weird edge cases. I also didn't have the option of anything higher wattage as I'm off-grid and reliant on solar. I love your e-ink idea though! Tempted to put a remote screen in with some simple stats and controls on.
Yeah the conclusion I'm coming to is that the Pi-likes all suffer from in some not entirely defined until you stumble upon it sort of way, not being 100% Pi-compatible. While in the old days I was happier to footle about getting things to work, I have a four year old and a job now. I really want to just have my hardware and software all work with minimal effort.
There's a tonne of excellent low-power display options available for the Pi from eink to LED matrices to segmented displays. I really want to find some way to use this ridiculous round LCD for something. And sure, they're mostly SPI devices and in theory there's nothing stopping them working with other devices but there are nice Pi-friendly python libraries out there and 99% of the time it's just as simple is "import solution; solution.dothething()"
btw, the eink screen I used is this one and it's pretty darn cool. Can be... um.. fun.. formatting stuff for it to display, if you do get one and you're hitting funtimes by all means drop me a line. I hit some hardware restrictions of the Pi Zero and got involved in some interesting workarounds.
Pimoroni have 2GB Pi 4 packages in stock right now (Pi + PSU + case deals), I've signed up for notifications when they get the 4GB boards but I'm not in a big rush anyway.
Nice one thank you! Love the colour e-ink.
Yeah I totally agree on the usability. I need to build a current shunt to measure an alternator and was prepared for a bunch of work but...I can just buy a breakout board for an off-the-shelf chip and stick it on the i2c bus. Then all I need to do is write a python driver that converts it to dbus messages. Except someone's already done that too. Job done!