As low power consumption as possible linux board

I'm looking forward to buy some boards for some projects, and one that I'm in need is a linux device to run Tailscale (VPN Service) and to be able to WoL my main computer (from afar). As I intend to leave it on at all times, just for that, idk what the best option would be. I don't think a GUI is needed, though I'm not versed enough in linux to CLI everything right easily.

I've come to know that a specific ESP32 is able to run linux, and it would seem the best fit for such a low hardware requirement of a project like that, but idk if it would actually work.

Other options considered are the Pi Zero, as it would work just fine, but it'd be a waste for a board capable of so much more to be left to do just that (Also I do fear it's going to be way too much power hungry, but I'm a complete noob when it comes to linux power management). But it does have HDMI video output, SD card slot, usb ports, it's quite more friendly than just GPIO

I've come to ask if there are any better suggestions or knowledge that would be useful. I hope to finish this project before august

Hi,

Welcome to LQ!

Originally Posted by Kuuh I'm looking forward to buy some boards for some projects, and one that I'm in need is a linux device to run Tailscale (VPN Service) and to be able to WoL my main computer (from afar). As I intend to leave it on at all times, just for that, idk what the best option would be. I don't think a GUI is needed, though I'm not versed enough in linux to CLI everything right easily. I've come to know that a specific ESP32 is able to run linux, and it would seem the best fit for such a low hardware requirement of a project like that, but idk if it would actually work. Other options considered are the Pi Zero, as it would work just fine, but it'd be a waste for a board capable of so much more to be left to do just that (Also I do fear it's going to be way too much power hungry, but I'm a complete noob when it comes to linux power management). But it does have HDMI video output, SD card slot, usb ports, it's quite more friendly than just GPIO I've come to ask if there are any better suggestions or knowledge that would be useful. I hope to finish this project before august

You mentioned above about using the Pi zero but to power hungry. How is the proposed board to be powered? The Pi zero will use 2 watts of power from your supply source. You might want to expound on your system design a little more. What is the supply power source? For WoL you might look at this project for some review; https://www.spokenlikeageek.com/2023...rry-pi-zero-w/

When you query the LQ forums please provide as much detail as possible so we can assist with an issue/design.

EDIT: Look at this link for some useful Pi Zero information; https://www.tomshardware.com/features/raspberry-pi-zero

Hope this helps.

The Raspberry Pi Zero, Zero W, and Zero 2W are wi-fi only unless you add an Ethernet HAT to them. They're about as low as you can get as far as power consumption on a general-purpose computer goes, especially the original Zero and Zero W. The 3A+ has all the Ethernet hardware built-in but consumes more power.

If you need even lower, then you might look at one of the Arduinos, such as the Nano Every. But note that is a microcontroller and not a general purpose computer and that it does not have Ethernet hardware without an Ethernet shield added to it. There might be a way to do that without a breadboard and without soldering ... maybe.

Welcome to LinuxQuestions.

The advantage of the PI Zero would be that a Tailscale package is already available for the Pi OS. You can turn off bluetooth which will save some power. I do not think the ESP32 would work for your project.

Would a thin client be sufficient(?), they run on low power, are standard Intel/AMD hardware.

Lots are available cheaply on Ebay, ex corporate.

Originally Posted by fatmac are standard Intel/AMD hardware

thus inherently insecure (Spectre, Spectre2, etc) and electricity hungry. Arm or a microcontroller would be the lowest power and avoid at least the built-in hardware level security holes.

Arm would be easiest but you can go lower with a microcontroller. The tradeoff is that it is a lot more fiddly to get a magic packet out of a microcontroller (e.g. Arduino) than a general purpose computer (e.g. Raspberry Pi).

electricity hungry

Very low ampage usage, 4~6 usually, less in standby 1~2.

Very low ampage usage, 4~6 usually, less in standby 1~2.

I have not measured my Pi Zero but there are reports running Pi OS lite headless (no desktop), disabling bluetooth, camera and lowering the frequency is on the order of 115 mA. If Tailscale is a hard requirement and it seems you do not have much experience with SBCs or linux then I am not sure that anything else would work for a lower power device.

Usually the core requirement for a network device is adequate resource to manage the maximum bandwidth expected at full speed. Power should normally be a secondary consideration.
Can you say WHY power usage is a consideration for your project?
Understanding the requirement better might prompt better recommendations.

Re-reading your question again, because of the Tailscale VPN requirement it sounds like you need a general-purpose computer. Also, it seems you would not find working with a micocontroller a productive experience (yet).

In that case I would suggest considering the Raspberry Pi 3B+ for your short list. Or, maybe, even a Raspberry Pi B+. Both have Ethernet for your Wake-on-LAN requirement. Either one can be configured to cut current to unnecessary services (if present) like HDMI, Wi-fi, and Bluetooth for reduced power consumption. Tailscale seems to provide a ready-made, pre-configured package for the Raspberry Pi. So my bet is that it is the easy way for you to go here.

I think esp32 can run a vpn client and can wake up another host, just you need to build your own software to run on it. (so it is not a full linux distro, but a compiled app). Or probably you can also use micropython. ESP32 can run on battery for a year, but obviously it depends on the code running on it.
From the other hand I assume you have a router, and your main computer is connected to the router.

First of all, tremendous thanks for your time and support.

My intention is to have a device running 24/7 solely for using Wake on Lan through Tailscale. Tailscale offers a curl installation easily acessible.

(surely would be glad to be able to use the board to control some other devices at my office, such as restarting my router through a relay, for example)

I have some experience with microcontrollers (such as arduino), and am quite used to soldering and basic electronic circuits. Am used to programming as well, but I do lack the knowledge/experience on how to use it to build software. It'd be a steep learning curve for me at the moment, mainly because I'll be building my graduation thesis/project this year. I'm ok with using a terminal to install stuff, but I do rely on automatic installers or tutorials most of the time.

I've gone through my numbers, and a Pi Zero seems to be a nice option for me right now. Idk if I'll grab a Zero, a ZeroW or Zero2W, and a USB lan adapter (or a ENC28J60 lan to gpio board). I may repurpose the device afterwards as a basic NAS with tailscale and the Wake on Lan function, or a media client, idk yet!

2 Watts is prety much low enough power consumption for me to have it running without any worry. I got interested on running this kind of stuff on a microcontroler but more for the amusement than pragmatism, I just thought the Pi would consume way much power. Also, I do not need anything close to a high LAN speed for this board, just the bare minimum to probably SSH into it and send these WoL packets. Surely bandwidth is welcome, as I could use it as an acess point to connect to other devices in my local network, but it's definetly not a priority at the moment.

I may rely on a basic setup for now, and I'm very glad for each answer to this thread. Some of you have joined this forum in 2002! I'm just 23 now and knowing a productive forum like this is still active to this day, after more than 20 years, is something that makes me happy. I'll be ordering my board and components as soon as May comes in. Will get some ESP32 just to toy with (in hopes of having any free time for other projects).

Thanks for welcoming me in

I designed a µcontroller powered device that ran on batteries at <1mA, because I ran it at 32.768KHz. People laughed at me for trying it, but I had the last laugh. It worked perfectly.

You can probably specify a very low clock frequency (arm_freq=20Mhz in /boot/config.txt) and still get faster networking because a pi Zero gets information in 32bit wide chunks and sends it out in serial. Keep going down until things malfunction, or the power stops reducing.

The formula for power consumption is: P(Watts) = ½C(Farads)V²F(in Hz). You can't change C or V, but you can change F. The Pi Zero is old, so wafer fab will be large(28nm or maybe 40nm). Get that spec for your thesis. That controls C. If it's possible to reduce Voltage, go after that too. I just have a Pi 4, and reducing voltage is not an option.