skip to Main Content

Power-Over-Ethernet Splitters are Good Fun!

Power-over-Ethernet is for more than IP phones, Wi-Fi access points and surveillance cameras. It can be used anywhere there’s a low-power device that would benefit from continuous power and the reliability of Ethernet connectivity. Assuming your network switch (or POE injector) is connected to a UPS, POE allows the attached devices to remain powered in the event of a power failure.

In my home and office, I use POE to connect and power a number of Raspberry Pi single-board computers configured as music players. The RPi3 B+ isn’t natively POE capable, so I use a POE splitter like the one pictured here.

Anvision POE splitter

Given a POE-capable switch upstream, this wee splitter provides 5 VDC at up to 2.4 A via a standard micro-USB connector. This model from Anvision is under $10. A 4-pack is just $37 on 

Turning Monitors On/Off

I have recently found a secondary advantage to leveraging POE for the music streamers. If the RPi is powered over the network it always appears as available to the Logitech Media Server (LMS.) I can use an Amazon smart plug to control power to the associated audio monitors at each location.

Amazon Smart Plug

Ideally, the smart plug would get a command from the LMS when I start something playing on its associated RPi. That would automatically power up the audio monitors when I start something playing.

While definitely doable, I haven’t quite implemented the server side script to accomplish that level of automation just yet. For the moment, I simply tell the echo to “turn on” the music at that location. A scheduled routine automatically turns off the powered audio monitors late each evening.

Beyond RPi

Alas, not everything can be powered via micro-USB. In some cases, a slightly different POE splitter is required. This model, also from Anvision, can provide 5, 9 or 12 VDC, switch selectable.

ANVISION Active Gigabit PoE Splitter Adapter with Multi-Size Tips

It also has a set of four interchangeable coaxial power tips. This allows it to be configured to power different kinds of devices.

Most recently, I’ve used one to power a very small form-factor computer. The tiny little computer that I have connected to a TV in my office needs 12 VDC at 2A. That’s well within what POE+ can deliver.

I bought this little PC for use at ClueCon 2018. It was to be an NDI playout device, accepting an NDI stream from the network and displaying it on a monitor. In that role it had to have real Gigabit Ethernet and enough grunt to reliably present a 120 mbps 1080p60 stream using Newtek’s NDI Studio Monitor application.

As it happens, I didn’t end up using the tiny computer in exactly that fashion. I have subsequently found the N3450 CPU and its lame-o Intel GPU are not quite up the task. It struggles to display 1080p60 without dropping some frames. That said, it does reliably deliver 1080p30.

Other Applications

I must admit that I’m intrigued by the Ubiquiti Networks Unifi LED lights. These are LED panels intended to fit into T-bar style drop ceilings in offices and industrial buildings. Paired with a mating UniFi Dimmer switcher they leverage 802.3at PoE+ to put the building lights on the network. That means easy remote control and monitoring via the same UniFi controller that tracks your Wi-Fi and managed switches.

Unfortunately, they don’t offer such items in a style that’s appropriate for a home office. It’s probably just as well.

There are clearly defined limits to how much power you can get from a network drop. So, there are cases were power from the network is just not practical. As POE standards continue to evolve the potential for its use expands tremendously.

Back To Top
%d bloggers like this: