Raspberry Pi is a popular platform choice for playing soft routing, but the original version has only one network port, which is inconvenient in some uses, and requires an external USB network port. Now if you want to make a soft router with dual network ports, you can use Raspberry Pi CM4, a company called Seeed Studio has given it a set of soft router expansion boards.
Raspberry Pi CM4 is launched in 2020. It adopts the hardware of Raspberry Pi 4, but removes the main interface, reduces the size of the PCB to the size of a credit card, and needs other functions that can be realized through the expansion board. This set of soft routing expansion board is the way to play, Its PCB size is only 6 inches in size, and it still maintains its compact characteristics, but the shell needs to be DIY by players.
This CM4 soft routing expansion board provides two full-speed Gigabit RJ45 wired network ports, as well as two USB 2.0 ports, microSD card slot, HDMI display output and other complete interfaces, and can be extended out of the Raspberry Pi standard 40-pin GPIO interface, and even a 0.91-inch monochrome OLED screen can be used to monitor network conditions, and it has OpenWRT firmware directly onboard, which is basically plug and play.
The CM4 can become a soft router, gateway, NAS, and small server after matching this expansion board. Seeed Studio said that the RTL8111E chip on the expansion board has better performance than the network card that comes with the Raspberry Pi, and can reduce the CPU load. , to provide a more stable network environment.
However, this routing expansion board is expensive at $55, and Raspberry Pi is hard to come by now, so this is really a plaything that is bigger than reality. If you are interested, you can put it in the shopping cart first, and the price of Raspberry Pi will come down. Toss again.