Raspberry Pi Power-over-Ethernet Injector zaps life into networks lacking spark

Official PoE+ HAT+ for the Pi 5 still MIA

The Raspberry Pi team has launched a Power-over-Ethernet Injector aimed at users who are seeking to add some juice to their network but who lack a network switch capable of doing so.

Power-over-Ethernet is a technology that brings power to devices over the network. It might seem redundant in a home lab environment, but being able to run power through an Ethernet cable, as well as data, opens up a variety of applications in places where plugging into a power oulet isn't an option.

The problem comes with the switch – something capable of supporting Power-over-Ethernet (PoE) is required. Where that's not possible, there is the Raspberry Pi PoE+ Injector, which supports IEEE 802.3af (PoE, 13 W) and IEEE 802.11at (PoE+, 25 W) standards, and mains voltages between 100 V and 240 V. Plug in a mains lead (not included) and some RJ45 connectors, and away you go.

This is assuming your devices can accept power this way. Raspberry Pi famously came somewhat unstuck with the Pi 3 Model B+ Power-over-Ethernet adapter. Problems with power to the USB ports were eventually traced to hardware issues that weren't picked up in testing before release.

There are plenty of other Power-over-Ethernet Injectors available from vendors, including TP-Link. The Raspberry Pi unit is priced at $25.

While Raspberry Pi computers since 2018 have been able to function as Powered Devices (PD), drawing from PoE, an optional PoE or PoE+ HAT (Hardware Attached on Top) has been required to make the magic happen. The official PoE+ HAT+ for the Raspberry Pi 5 was absent from the announcement.

Some third-party options exist, or a splitter that breaks out a USB-C power connector is available. However, in the product announcement, Pi supremo Eben Upton wrote: "This promises to be our smallest, most efficient PD accessory, and is in the final stages of development."

We asked Upton what the hold-up was: "The principal cause of delay is that for the first time it features a planar transformer on our own PCB. So a ferrite clamped around the PCB, rather than a separate wound object (like the PoE HAT) or a planar transformer from a third party (like the PoE+ HAT)."

"Lots of engineering challenges!" he added.

"The end product is incredibly Spartan-looking, with very few components, and fits inside the official case, with most of the clever stuff sitting in the space between the fan and the USB and Ethernet connectors." ®