Waveshare’s $38 “Compute Module PoE Board” extends the Raspberry Pi CM3 with a PoE-enabled 10/100 LAN port, 4x USB, HDMI, MIPI-DSI and -CSI, 40-pin GPIO, and an optional case.

We’ve seen a variety of embedded systems based on the Raspberry Pi Compute Module 3, including IoT gateways such as CompuLab’s IOT-GATE-RPi and automation controllers like Techbase’s ModBerry or Brainboxes’ BB-400 NeuronEdge Controller, which is based on the wider temp, up to 32GB eMMC RPi CM3+. CM3-based development boards include Gumstix’s Alexa Voice Service, Kontron’s Passepartout, and balena’s balenaFin. among others. Waveshare‘s new Compute Module PoE Board joins this second group with a low $38 price and Power-over-Ethernet.

Compute Module PoE Board with RPi CM3 (left) and rear view
(click images to enlarge)

Although you can get a faster board with more features and less money with a Raspberry Pi 4 with a PoE HAT, Waveshare’s product is designed primarily for evaluating the CM3 or prototyping custom systems built around the CM3. (It can also be used for final products, says Waveshare.) The $38 price does not include the cost of the $25 to $30 CM3 or CM3+ module. There’s also an enclosed, $50 version of the PoE Board called the CM-IO-POE-BOX that also ships without the CM3/CM3+ (see farther below).

As noted by the CNXSoft story that alerted us to the product, the Compute Module PoE Board follows Waveshare’s $47 Compute Module IO Board Plus. This larger board offers features not found here, including 1-wire, ADC, DAC, RTC, IR, a sensor interface, and an Arduino header. However, it has no LAN port, let alone PoE. Waveshare has made other Raspberry Pi related products such as the RPi Camera G and Raspberry Pi 10.1 inch touchscreen, and this year it extended the Jetson Nano module with a JetBot AI Kit for robotics.

The 114 x 84.4mm Compute Module PoE Board builds on the CM3 or CM3+ modules, which offer quad-core Cortex-A53 Broadcom SoCs clocked to 1.2GHz with 400MHz VideoCore IV GPUs. There’s also 1GB of LPDDR2 RAM and either 4GB (CM3) or 8GB to 32GB eMMC (CM3+). The board also supports the Lite version of either model, which lacks eMMC storage.

Compute Module PoE Board detail view and legend
(click images to enlarge)

The 10/100 Ethernet port offers 802.3af-compliant Power-over-Ethernet with 37-57V DC input and 5V, 2.5A DC output. It’s accompanied by an Si3404 PoE PMIC, an EP13 PoE transformer, and PoE voltage measuring pads. There’ also an opto-isolated SMPS (Switching Mode Power Supply).

The Compute Module PoE Board is further equipped with 4x USB 2.0 host ports and 3x micro-USB ports. One is for power input, another for UART debug, and the third client/slave interface supports burning of system images.

Media interfaces include an HDMI port, a MIPI-DSI interface, and dual MIPI-CSI camera inputs. Other features include a microSD slot, dual LEDs, a fan interface, and a 40-pin GPIO connector. This is an open-spec board, with posted schematics and open source code for fan and camera interfaces.

The CM-IO-POE-BOX model adds a metal case, a power supply, and a cooling fan that can be controlled by software via GPIO. Cutouts are provided for all peripherals. With the mounting hole extensions, the dimensions are 144 x 88 x 30mm.
 
Further information
The Compute Module PoE Board, which is also referred to as the Raspberry Pi Compute Module IO Board with PoE Feature, is available for $38 at Waveshare and Seeed. The CM-IO-POE-BOX enclosure version is available at Seeed for $50 and at AliExpress for $56.41. More information may be found at Waveshare’s Compute Module PoE Board wiki.