Raspberry Pi Grants Remote Access Via PCIe (Sort Of)

September 20, 2022 by Al Williams 28 Comments

[Jeff] found a Raspberry Pi — well, the compute module version, anyway — in an odd place: on a PCI Express card. Why would you plug a Raspberry Pi into a PC? Well, you aren’t exactly. The card uses the PCI Express connector as a way to mount in the computer and connect to the PC’s ground. The Pi exposes its own network cable and is powered by PoE or a USB C cable. So what does it do? It offers remote keyboard, video, and mouse (KVM) services. The trick is you can then get to the PC remotely even if you need to access, say, the BIOS setup screen or troubleshoot an OS that won’t boot.

This isn’t a new idea. In fact, we’ve seen the underlying Pi-KVM software before, so if you don’t mind figuring out your mounting options for a Raspberry Pi, you probably don’t need this board. Good thing too. Judging by the comments, they are hard to actually buy — perhaps, due to the chip shortage.

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True Networked KVM Without Breaking The Bank

November 24, 2020 by Bryan Cockfield 27 Comments

For administering many computers at once, an IP KVM is an invaluable piece of equipment that makes it possible to get the job done over the network without having to haul a keyboard, monitor, and mouse around to each computer. The only downside is that they can get pricey, unless of course you can roll one out based on the Raspberry Pi and the PiKVM image for little more than the cost of the Pi itself.

The video linked below shows how to set all of this up, which involves flashing the image and then setting up the necessary hardware. The build shows an option for using HDMI over USB, but another option using the CSI bus would allow for control over options like video resolution and color that a USB HDMI dongle doesn’t allow for. It also makes it possible to restart the computer and do things like configure BIOS or boot from removable media, which is something that would be impossible with a remote desktop solution like VNC.

The creator of PiKVM was mentioned in a previous post about the creation of the CSI bus capture card, and a Pi hat based on this build will be available soon which would include options for ATX controls as well. Right now, though, it’s possible to build all of this on your own without the hat, and is part of what makes the Pi-KVM impressive, as well as its very low cost.

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Incredible Soldering In The Name Of Hardware Support

September 5, 2020 by Tom Nardi 31 Comments

If you’re developing a performant IP-KVM based on the Raspberry Pi, an HDMI capture device that plugs into the board’s CSI port would certainly be pretty high on your list of dream peripherals. Turns out such devices actually exist, and somewhat surprisingly, are being sold for reasonable prices. Unfortunately the documentation for the chipset they use is a bit lacking, which is a problem if you’re trying to wring as much performance out of them as possible.

As the creator of Pi-KVM, [Maxim Devaev] needed to truly understand how the Toshiba TC358743 chip used in these capture devices worked, so he decided to build his own version from scratch. In the name of expediency, he didn’t have a proper breakout board made and instead decided to hand-solder the tiny BGA chip directly to some parts bin finds. The resulting perfboard capture device is equal parts art and madness, but more importantly, actually works as expected even with 1080p video signals.

Ultimately, the lessons learned during this experiment will lead to a dedicated KVM board that will plug into the Pi’s expansion header and provide all the necessary hardware in one shot. As [Maxim] explains in the Pi-KVM docs, the move to the CSI connected Toshiba TC358743 cuts latency in half compared to using a USB capture device. That said, USB capture devices will remain fully supported for anyone who just needs a quick way to get things working.

This DIY capture card is a perfect example of how the skills demonstrated while working on a project can be just as impressive as the end result. [Maxim] didn’t set out to hand-solder a BGA HDMI capture chip, it was merely one step in the process towards creating something better. Those intermediary achievements are often lost in the rush to document the final project, so we’re always glad when folks take the time to share them.

[Thanks to Eric for the tip.]