52Pi, best known for its innovative cooling devices for the Raspberry Pi family of single-board computers, has launched a carrier board for the Raspberry Pi Compute Module 4 (CM4) — turning it into a router or network appliance with two gigabit Ethernet ports.
"[The] CM4 Router Board is an expansion board based on the Raspberry Pi Compute Module 4," the company explains of its latest launch. "It brings Raspberry Pi CM4 two full-speed gigabit network ports and offers better performance, lower CPU usage, and higher stability for a long time work[ing] compared with a USB network card."
Designed for both the Raspberry Pi CM4 and the CM4 Lite, the latter lacking on-board eMMC storage and instead using a microSD slot on the carrier board itself, the CM4 Router Board includes two full-speed gigabit Ethernet ports with the option of Power over Ethernet (PoE) support via the Raspberry Pi PoE Hat or PoE+ HAT. One port connects to the CM4's on-board Ethernet, with the other tying a Realtek RTL8111E controller into the system-on-module's PCI Express lane.
Elsewhere on the board is a full-size HDMI output, a single USB 2.0 port selectable as USB Host or Deviec, a USB Type-C power input, and a 40-pin general-purpose input/output (GPIO) header. 52Pi has also included a compact 0.91" OLED display, connected to the Raspberry Pi CM4 over I2C, and a 5V fan header with pulse-width modulation (PWM) control - though no fan is bundled.
The board is technically supported by any operating system compatible with the Raspberry Pi family of single-board computers, but 52Pi is concentrating on the use of OpenWRT as a router, gateway, firewall, or other network appliance requiring two Ethernet ports. For those who need more than two, the company recommends pairing the board with an external gigabit Ethernet switch.
The 52Pi CM4 Router Board is listed on Seeed Studio at $54.90 before volume discounts, supply-your-own Raspberry Pi CM4; at the time of writing, however, the item was shown as out of stock.