Ask HN: Is it possible to create USB terminal keyboard/display?

by djl0on 1/18/2021, 4:09 PMwith 2 comments

Hi HN,

When my headless home server inevitably goes unresponsive after a power outage or something (I know I should get a better power supply), I have to fetch my big display monitor and keyboard to diagnose and get it back online.

Does there exist a device, or is it fairly doable to make one, which would be like a RPi-400 + display which could connect via USB to view and operate the terminal? I guess secondarily, a small or handheld terminal display is really the most important piece, since plugging in a usb keyboard is fairly trivial (could android phone be used for this?).

This seemed like a project that one of you smart people would have tried out, and I just thought I'd ask.

Or if there's a much easier solution than what I've been doing, I'd love to hear.

Thanks

by detaroon 1/18/2021, 4:31 PM

anything with purely USB won't work in BIOS or recovery system etc where a matching driver for whatever USB-graphics thing it is using isn't loaded.

If your server has HDMI out, you can use a cheap HDMI-USB-capture dongle with a laptop, smartphone or tablet. (small portable HDMI screens are also available, but for occasional use buying one is overkill). VGA capture modules are more expensive, but should also exist.

Otherwise a traditional way is a serial console, which again would need a serial adapter for whatever device you use with it - again depends if your hardware has a serial port and (if BIOS is relevant) if the BIOS talks over it.

by ThrowawayR2on 1/18/2021, 5:01 PM

Well, there exist rack consoles for datacenter use which can be found used on eBay. However, you might need a video converter since they are VGA only; rackmount servers only have VGA video outputs.

The least expensive option would be to buy a second small monitor.