Seeed Studio has created a Raspberry Pi Router Board specifically for the Compute Module 4 (CM4). Officially called the Raspberry Pi Router Board for CM4 module, the device contains two Gigabit Ethernet ports and supports PoE via an appropriate HAT. Correspondingly, the carrier board supports the standard Raspberry Pi HAT interface and contains a PCIe port for its second Ethernet connection.
Additionally, the board also features a 0.91-inch IIC OLED display that display its operating status. Meanwhile, Seeed Studio has included an HDMI port, USB ports and a microSD card slot, a required feature for CM4 units without built-in eMMC flash storage. Moreover, Seeed Studio has ensured 40-pin GPIO compatibility via a header that sits next to the CM4's mounting points. Similarly, the company has equipped the board with a 5V DC fan interface that supports PWM control.
According to Seeed Studio, the carrier board requires setting up with OpenWrt, a Linux-based customisable operating system for embedded devices. However, Seeed Studio also promises compatibility with Raspberry OS, Ubuntu Server and other Raspberry Pi systems. Currently, the board is orderable from Mouser for £53.40, although there is an eleven-week factory lead time at present. Generally, the device should be orderable from Seeed Studio directly for US$54.90, or US$51.90 if you order more than ten units.