The KVM Project Story [001] – The Idea

A few years ago I scored a great deal on several HP Elite Desk 600 Mini PC’s. I purchased 5 and was giving a price per unit of roughly $33 USD. I upgraded the ram in all of them from 8GB to 16GB, kept 3, and sold two on eBay for around $60 each. I was about $200 all in, and after selling those two online, was feeling pretty good about getting three of these costing roughly $27. The idea was I’d set them all up with PROXMOX and use them for some of my own hosting needs, including a Kubernetes cluster.

Everything went well, except the processes of setting up these devices and wiping them. I have a small house and a lot of kids. Not a great combination for setting up, taking apart and working on five computers. These computers also required a display to be connected to boot. I would later get some dummy dongles for this, but that mean having a monitor hooked up. I kept thinking to myself the entire time, “How is it there is no simple KVM cable that I can just plug in and use my laptop as Keyboard, Mouse, and Display for these machines I’m working on?” As it turns out, there was, they are called crash karts, and they were around $500.

I reeled at price, I couldn’t believe it. A little more looking around, and I came across several Raspberry PI projects. Even these options were hundreds of dollars, and came with setup complexity. How hard could it be to just have a single cable on the controlling side, and a display cable with mouse/keyboard cable on the other.

As I looked into the issue more, I started thinking seriously, maybe this was something I would have to create myself. I had some cheap HDMI USB2.0 capture cards I had purchased, they were a little latent, but for the price pretty good. I also knew the RP2040 PICO and some Arduino variants could be configured as a HID device. And so the idea was born, if I could combine a cheap capture card, and a cheap MCU with reasonable software, I could create the tool I always wanted but didn’t have. And If I was looking for it. Maybe others were too.

It was the summer of 2022, and by the end of August I had the HDMI capture card working with OpenCV-Python and had a working Python script for capturing keystrokes.