Can anyone recommend a simple micro-controller with some I/O (<8) that can be powered using PoE, something cheap like Raspberri Pi Zero. The requirements are:

  • Support PoE integrated. No power battery maintenance.
  • Support TCP/UDP communication
  • few I/O.

The thing is that if I need a power adapter per each micro controller distributed around the house I will require a lot of budget. Having a set if chips with PoE I avoid occupying the power outlets and I have safe communication at the same time.

Basically what I want is to through some Ethernet cables and add some sensors and actuator without having to set up a full Arduino in each end-point. And not having to change the battery every year. And also I don't want to spend extra money buying adfruits and shields.

Another alternative that fulfill somehow my requirements, although it is not what I was thinking of, it is to install a commercial Wi-Fi power outlet. I find it bit expensive for the amount of units I need.

Here is one example from Amazon.

  • This solves my power requirements by taking the power directly from the power net.
  • Provides communication over Wi-Fi.
  • I can connect any microcontroller with a power adapter to it.
  • Since it is commercial Hardware I believe that it will provide some safety level of operation, in comparison to a testing board I could do on my own, I won't like to set the kitchen on file because a silly short cut.

Of course, the fun will be to develop the application by myself

Orvibo Socket

  • 2
    You say you want a microcontroller, but then give an educational product board as an example. POE would be a property of a board, not an MCU. Various wiznet, HC9S12NE64 (if you can still get them) etc Embedded Ethernet solutions can probably be rigged up with add-on POE extraction. Chances are you can create a cheaper solution around some electrical variation of a serial port compared to Ethernet - you'd need a head-end bridge, but the cost per node could be cheaper, and MCU nodes won't take advantage of Ethernet bandwidth. Feb 10, 2017 at 16:43
  • 6
    I like your question because the problem is real. PoE is a good idea and maybe instead of asking direct product recommendation you could ask about a how to add PoE support to your designs. Feb 10, 2017 at 16:52
  • 1
    These comments are valuable and appreciated. My second option would be to replace the original requirement of PoE and TCP/IP by something more common in small boards, which is USB (Power+communication) but I doubt that such solution is cheaper, flexible, reliable and more scalable, besides I don't think that a real IoT project will use a net of USB nodes devices interconnected with a HUB. Anyway, I will do a quick research on the USB phisical properties. Feb 11, 2017 at 8:02
  • @SnakeSanders what are you actually trying to achieve here? You're talking about an application, but not what this application is going to achieve.
    – aaa
    Oct 9, 2017 at 17:59

7 Answers 7


Orange Pi Zero is cheap (7$ + shipping), can be hacked to run on passive PoE, supports TCP/UDP over on-board ethernet and wireless and has a few I/Os.

It's not exactly a microcontroller in my book, it's more like a small headless linux computer, but then you mention raspberrypi zero as a reference which is in the same class.

When using it, be sure to use the armbian distro and consult their forum for power consumption and wireless hints.

EDIT: Warning, the currently (Sept 2017) sold board revision 1.4 of the orange pi zero suffers from an overheating problem. It is not recommended to buy this board at the moment.


You do not need PoE for your setup. Just use two wires from Ethernet cable to power your controllers.

Ethernet cables have four unused wires: 4 (blue), 5 (white with blue), 7 (white with brown) and 8 (brown). For personal use, I believe, you can use these wires for powering up your micro controllers. Of course, you should take precautionary measures in case you or next user of your infrastructure will use it incorrectly. I would tag wires or put warning label.

  • TIL that it is called "Passive Power over Ehternet" en.wikipedia.org/wiki/Power_over_Ethernet. Oct 11, 2017 at 8:51
  • 2
    A big difference between "real" POE and this would be that POE uses a high voltage and lower current to minimize losses over moderate distance. You'd probably be supplying the MCU's operating voltage or regulator headroom above, so higher current. But if the overall current is low that can work. For something like a flash-based MCU this could be fine, for something power-hungry like a raspberry pi you may start to run into issues once you have several meters of cable. Also keep in mind a real POE receiver probably has some protection against overvoltage spikes coupled onto the cable. Jul 8, 2018 at 16:24

Arduino do a board with built in PoE, but at double the price of a Pi last time I looked, I would not consider it cheap. And sounds physically bigger than you are looking for.

The is also the Arduino Yun with poe, but that costs even more

If a pi Zero W will do what you want you can get PoE adapters for of the order of £8 each singularly, possibly cheaper in bulk which could be used to drive a pi Zero (or full sized)


The VoCore 2 + PoE dock will do this; I'm not sure if they're going to do another manufacturing run or not though.


I was using Itead Iboard arduino based ethernet board, powered by passive PoE adapter. I bought them for 14$ each, poe adapters can be purchased for less than $1 on ebay. Since it is MCU based, it boots instantly, doesn't require SD card, totally safe and cannot be hacked. I use it for home weather monitoring system using both TCP and UDP protocols with temperature/humidity/barometric/motion/rf sensors. There are currently 4 such devices on my network working without any problem. But for some sad reason they discontinued this product, so I am currently looking for replacement. And there is also one downside of using small footprint MCUs for networking - it is difficult to get secure http (ssl) working there.

Pros of using Arduino MCU over linux boards:

  • linux take long time to boot
  • regularily discovered new security vulnerabilities on linux systems
  • needs to be upgraded to keep it safe
  • if not configured properly, SD card worns out quickly
  • consumes more power than MCU board


  • only for simple applications because of memory constraints
  • not powerful enough even to host website
  • good for simple GET/POST http requests
  • too weak computational power to handle SSL
  • forget about using SD card
  • doesnt provide linux shell
  • unable to log to it remotely to upload new software

I list microcontrollers up to 30 EUR here. I'll keep looking and update this if I find something interesting. A really good solution would be something below 10 EUR, but I haven't found anything like that.

  • The Lantronix XPort is 30 EUR + shipping, in theory that would work too, but the prices are interesting, they are between 20 and 200 EUR, so hard to tell which one is the real price.
  • The Orange PI Zero is 28 EUR + shipping, I don't know from where the other answerer got that 7 USD price. In Europe that is very far from the truth. I don't think you can buy it in the US that cheap either.
  • The Olimex ESP32-POE-ISO is 25 EUR + shipping. There is a cheaper version for 18 EUR, but it is not galvano isolated, so it is easy to fry.
  • The Itead IBoard is for 20 EUR + shipping currently, but it is relative rare.
  • The PI Zero W + POE splitter is 16 EUR + shipping total at least. The active POE micro USB splitter is 6 EUR at least, which is relative expensive. The PI Zero W is currently 10 EUR.
  • The ESP32 is 5 EUR, but it does not have POE or even RJ45 normally. It is possible to add POE the DIY way, so with a little luck you might end up with the ESP32-POE-ISO if you have the right skills. I don't.

Today I found the W5500 Ethernet with POE IOT Board (Arduino Compatible) which is also available on Ali Express. However it has a price tag of ~$35.

Not the answer you're looking for? Browse other questions tagged or ask your own question.