An open-source hardware build-it-yourself device to
remote-control up to 48 devices via their RS-232 serial port.

The hardware

There’s a Raspberry Pi 2 inside, so you can either follow our guide and run Debian GNU/Linux on it, or install your favorite operating system on its powerful 900 MHz quad-core ARM processor.

freetserv uses the FT4232HL chip, which is well-supported by Linux and BSD operating systems. No custom drivers are needed.

Pinout-wise, freetserv is compatible with the popular cisco console cables that you might already be familiar with.

The schematics and board layout are published under the CERN Open Hardware license.

Why use serial ports?

freetserv originated from a small server hosting colocation association where we share a 19″ rack; each member gets one unit.

Some devices like network switches or appliances come with a serial port and no other way to access them remotely.

Servers often have more modern remote management facilities like IPMI, but we weren’t too happy with that, no matter which server vendor we are talking about. Occasionally, the IPMI module would just crash (!) and need a reboot. Sometimes IPMI wasn’t reachable in early boot when you needed it most due to its network port sharing. And even when it works, it provides a huge attack surface.

In conclusion, some of our members prefer to turn off IPMI and use a good old serial port instead. Others take all the backup they can get and want to have both IPMI and serial port access.

Getting started

If you’re a freetserv user, see the User Guide for how to identify and use your serial ports.

If you’re a freetserv admin, the Admin Guide explains how to add users and assign ports.

Read the Assembly instructions to learn how to build a freetserv after you’ve bought the Materials.
Before deciding to build a freetserv yourself, check out the known issues!

If you don’t want to go all the way and prefer to build a terminal server from a commercial option, check out Coolgear’s 32 Port RS-232 USB-to-Serial adapter (USB-32COM-RM). Find more detail in lathama’s notes.

We also have a bunch of pictures if you’re just curious.