A KVM switch is a piece of hardware that allows you to control multiple computers from one set of keyboard, monitor and mice.
In this post we’ll take a closer look in a KVM constructed around a Raspberry Pi 3B+ or 4B.
This version of KVM is able to work over the internet. This makes it possible to do remote reboots and/or shutdowns, installations and so on.
A quick quote from the Pi-KVM team:
A very simple and fully functional Raspberry Pi-based KVM over IP that you can make with your own hands. This device helps to manage servers or workstations remotely, regardless of the health of the operating system or whether one is installed. You can fix any problem, configure the BIOS, and even reinstall the OS using the virtual CD-ROM or Flash Drive.mdevaev
- Raspberry Pi 4 (or 3B+)
- Power/Data Splitter
- HDMI Video capture*
- To USB
- To CSI
- HDMI cable
- Cabled network
- SD card
- USB RPI Power supply (3A)
There are 2 ways to get the required HDMI input, using a USB capture device OR use the camera input using a CSI board.
Note that de USB capture device has a higher delay.
It’s completely supported and Pi-KVM works great with it. But it has some disadvantages compared with recommended HDMI-CSI bridge: USB gives a lot of latency (200ms vs 100ms) and it doesn’t support stream compression control (you won’t be able to use Pi-KVM in a place with a poor internet connection).mdevaev
In this first Episode we’ll take a look on the USB Capture device way.
This uses one of the USB connectors (FIXED one).
You can find a nice tutorial on YouTube (Not Mine):
For a full install guide I’ll redirect you to the github of this project.
But here is a short version:
The splitter is only required if you wish to mount an ISO file to your remote server/pc.
This allows you to also control the ATX from the PC/Server. More on this you’ll find in the GitHub. this is only possible when using a Pi4 or a Pi Zero as only they have an OTG function build in. You’ll need a Pi4 or Pi Zero if you wish to use a remote keyboard and mouse.
The next thing we’ll need to do is install the software.
There is a prebuild version available but for those who want to build it themself there is that possibility to.
Download here for USB version.
Using the software
Once booted you’ll need to figure out the IP address of the Pi-KVM.
I use an IP scanning tool that scans my network, in my case I got 192.168.1.10.
In Linux you can use NMAP for this
Open your flavour browser and browse to the IP address you just found. You will be asked for a login and password, unless you have changed it in the console this will be admin – admin.
You can change this using the following command in the terminal:
kvmd-htpasswd set admin
Note that to login to the terminal you need the root login with password root.
Change the root password using the passwd command in the terminal.
Once logged in you’ll get the change to go to the KVM stream or Terminal.
In the case above no stream is active and it will give you a test screen.
In the upper right corner you can change some settings like mount a drive to the remote server, setting keyboard and screen settings.
The Pi KVM is a great piece of work, many thanks to the developer of this project (mdevaev).
In the next episode we’ll take a closer look at drive mounting, ATX control and the system settings.
If you have any question, pointers or remarks. Head over to our contact page and contact from there.
Otherwise I’ll see you in the next episode.