A very simple and fully functional Raspberry Pi-based IP-KVM 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.
A ready-to-use OS that can be created just by running `make build` and installed to an SD-card using `make install`. The hardware can be made in half an hour and without soldering.
There are many ways to build a Pi-KVM. Video capture devices can be attached using the CSI-2 or USB interfaces. Raspberry Pi models 2, 3, 4, or ZeroW may be used. Any combination of hardware is supported, and Pi-KVM implements the maximum possible set of features.
With a very simple circuit that can be assembled on a breadboard, the power button of the attached server can be controlled using the ATX button headers on the motherboard.
Pi-KVM can be opened to the Internet and no one will get access without the password. SSL encryption is used to protect traffic from being intercepted by third parties.
The Pi-KVM OS is based on [Arch Linux ARM](https://archlinuxarm.org) and can be customized for any needs. Thousands of pre-built binary packages are at your service and can be updated with a single command!
Multiple Pi-KVMs can be configured to use a [common authorization service](https://github.com/pikvm/kvmd-auth-server). PAM and its rich authorization mechanisms can also be used to integrate Pi-KVM into your existing authentication infrastructure.
If repetitive actions must be perfromed on the attached server (or on several different servers), a macro can be recorded with keyboard & mouse actions and can be played back mutiple times.
We created [our very own MJPG video server](https://github.com/pikvm/ustreamer) written in C with multi-threading support and GPU video encoding - the fastest streaming solution available to provide the best video quality for Pi-KVM. We also tested a lot of hardware configurations so that you can be sure devices you assemble will work reliably.
* **Recommended**: **v2** is the most modern implementation for **Raspberry Pi 4** and **ZeroW** supporting all of the features of Pi-KVM including the **Mass Storage Drive**. **It's also the easiest to make**
* v0 was designed to work with Raspberry Pi 2 and 3 that do not have OTG and requires a few more components for a basic implementation. It also does not support the Mass Storage Drive feature.
- ... or [HDMI to USB dongle](https://aliexpress.com/item/4001043540669.html) (not available for ZeroW) - high latency ~200ms, [not very reliable](#a-few-words-about-hdmi-usb-dongle)).
It's completely supported and Pi-KVM works great with it. But it has some disadvantages compared with recommended [HDMI-CSI bridge](https://aliexpress.com/item/4000102166176.html): 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). It also cannot automatically detect screen resolution. All this is caused by the hardware limitations of the dongle itself. In addition, some users report hardware problems: the dongle may not work in the BIOS or simply stop working after a while. It's a black box, and no one knows what's inside it. If you have problems with it, it will not be possible to fix them.
* Pi-KVM can be powered using PoE, but it is not recommend to use the official PoE HAT: it is unreliable and [not compatible with the HDMI bridge](https://github.com/pikvm/pikvm/issues/6). Use any other PoE hat without an I2C fan controller.
* **Don't use random relay modules or random optocouplers!** Some relays or optocouplers may not be sensitive enough for the Raspberry Pi, some others may be low-level controlled. Either use relays that are activated by a high logic level, or follow the design provided and buy an OMRON. See details [here](https://github.com/pikvm/pikvm/issues/13).
**Sounds interesting? [Subscribe in this form](https://docs.google.com/forms/d/1LA6iEYVtbJULvMDNktyNQMI4N9SYdNG03Wh9WK-80cM)** or join to https://discord.gg/bpmXfz5 and we will let you know when you can purchase the board. **Prototypes will be ready in Q4 2020**, and pre-orders will be available sooner. If you are considering ordering a wholesale lot, please email to mdevaev@gmail.com.
Insert the flexible flat cable of the HDMI bridge into the narrow white connector on the Raspberry Pi (the closest one to big USB sockets). Make sure that the cable is inserted on the correct side and until it stops, and then snap the black latch. Never connect or disconnect the flat cable from a powered device. This is not Plug-and-Play, and you can damage it. Also use only the cable that was included with the device package, or make sure that the third-party cable has the correct pinout.
There are many revisions of the Raspberry Pi boards and you may come across one that we haven't tested. If the binding fails, the device will be available for all ports. Everything will work, but if you use a webcam and Linux mistakes it for a dongle, [write to us](https://discord.gg/bpmXfz5) and we will fix it.
**Raspberry Pi 4 note**: since one USB-C female connector is used to receive power and perform keyboard/mouse/drive emulation a special Y-cable must be made that splits the DATA and POWER lines of USB-C (see [reasons](https://github.com/pikvm/docs/issues/11)). It can be made from two suitable connecting cables, or soldered together from scratch. Be sure to check the circuit diagram below, otherwise you may damage your devices. The appropriate USB pinout(s) can easily be found on Google. Please note that if you make a Y-cable from two no-name cables, the colors of the wires may not match those shown. Use a multimeter to make sure the connections are correct.
Here the final steps. There are two ways to get the Pi-KVM OS:
* We provide the ready-made images for **Raspberry Pi 4** for platforms **v2-hdmi** (the CSI-2 bridge) and **v2-hdmiusb** (the USB dongle). [Follow these instructions](pages/flashing_os.md) to install the OS quickly.
* For the other boards and platforms, you need to build the operating system manually. Don't worry, it's very simple! [Just follow these instructions](pages/building_os.md). You can also build the OS for RPi4 manually if you really want to :)
Congratulations! Your Pi-KVM will be available via SSH (`ssh root@<addr>` with password `root` by default) and HTTPS (try to open in a browser the URL `https://<addr>`, the login `admin` and password `admin` by default). For HTTPS a self-signed certificate is used by default.
To change the root password use command `passwd` via SSH or webterm. To change Pi-KVM web password use `kvmd-htpasswd set admin`.
You can use port forwarding for port 443 on your router if it has an external IP address. In all other cases, you can use the excellent free VPN service [Tailscale](pages/tailscale.md), which is configured on Pi-KVM with a [few simple commands](pages/tailscale.md).
* In very rare cases, old motherboards contain a buggy BIOS that does not understand the keyboard of the **v2** platform (bellow). The reason for this is that the BIOS doesn't fully implement the USB HID stack for composite devices correctly. Meanwhile, Mass Storage Drive will be detected. For this case, we suggest using the Arduino HID from the **v0** platform with **v2**. Thus the Pi-KVM will be connected by two USB cables to the motherboard: one of them will be responsible for the keyboard and mouse, the other for everything else. See [here](pages/arduino_hid.md).
* A similar problem can be observed on devices with UEFI: the keyboard works fine, but the mouse does not work. This problem is much less significant, since all UEFI can be configured using the keyboard and hotkeys, without the mouse. If you want to get a mouse, the solution will be the same: using an Arduino HID, as in the advice above.
Our future [v3 platform](#the-future-v3-platform-work-in-progress) will contain an optional HID module for such cases, so you won't have to build anything yourself.
* The Pi-KVM file system is always mounted in read-only mode. This prevents it from being damaged by a sudden power outage. To change the configuration you must first switch the filesystem to write mode using the command `rw` from root. After the changes, be sure to run the command `ro` to switch it back to read-only.
* **NEVER** edit `/etc/kvmd/main.yaml`. Use `/etc/kvmd/override.yaml` to redefine the system parameters. All other files that are also not recommended for editing have read-only permissions. If you edit any of these files, you will need to manually make changes to them when you upgrade your system. You can view the current configuration and all available KVMD parameters using the command `kvmd -m`.
* Almost all KVMD (the main daemon controlling Pi-KVM) configuration files use [YAML](https://docs.ansible.com/ansible/latest/reference_appendices/YAMLSyntax.html) syntax. Information on the format's syntax can be found at the link provided.
* To use Wake-on-LAN with your server you must define some options such as the server's MAC address and (optionaly) IP address. Use `/etc/kvmd/override.yaml`. The format is:
Replace `ff:ff:ff:ff:ff:ff` with the MAC of your server. By default, a packet is sent via a broadcast request to the entire IPv4 network (`255.255.255.255`, port `9`), but you can address it to a specific static address:
* To use IPMI BMC you need to set up an appropriate account and run the `kvmd-ipmi` daemon (`systemctl enable --now kvmd-ipmi`). Although Pi-KVM supports the IPMI protocol, we strongly recommend that you do not use it outside of trusted networks due to the protocol's [insecurity](https://github.com/NitescuLucian/nliplace.com.blog.drafts). Refer to the file `/etc/kvmd/ipmipasswd` to configure IPMI account.
* **Unexpected interruption while loading the image for Mass Storage Drive**
If problems occur when uploading even a small disk image it may be due to unstable network operation or antivirus software. It is well known that Kaspersky antivirus cuts off Pi-KVM connections during uploading, so you should add the Pi-KVM website to Kaspersky's list of exceptions or not filter web requests with the antivirus. Antivirus programs can also affect the performance of certain interface elements, for example the quality slider.
For Kaspersky, the steps to add the network address of Pi-KVM's website to the exclusion list is: **Protection -> Private browsing -> Categories and exclusions -> Exclusions**
If you can't or don't want to enable the CSM, you can try connecting a DisplayPort monitor, or a [dummy plug](http://amazon.com/s?k=displayport+dummy+plug). If you remove the DP cable/adapter the bug will reappear.
If none of this works, try connecting the DP cable first, boot into the BIOS, disable the CSM and shutdown (do not restart) your PC. Then, boot into the BIOS and enable the CSM before shutting down your PC. Then connect the HDMI and turn your PC on again.
* **Awesome WM on Linux** sometimes can't recognize a video output change on a cable. That is, if the cable was first inserted into the monitor, and then you reconnected it to Pi-KVM - it may happen that you will not see the image. It seems that the problem is Awesome WM, since for example with KDE it does not reproducing. If you turn on your workstation with Pi-KVM already connected, everything will work fine.
**Q:** **Can I connect multiple servers to a single Pi-KVM?**
**A:** Yes, but it will require additional work to set up. Pi-KVM can be connected to a multi-port HDMI/USB switch and the switch's buttons can be connected via optocouplers to the Pi's GPIO pins to switch channels. If your KVM switches channels using keyboard shortcuts, there is a chance that it will not be able to work with OTG (v2 platform, see bellow), since it does not fully implement the USB stack. In this case, you will have to use an Arduino board to emulate the keyboard & mouse. (Pi-KVM supports this configuration)
**Q:** **Can I use Pi-KVM with non-Raspberry Pi boards?**
**A:** Yes, but you will have to prepare the board OS yourself. As for the Pi-KVM software, you will need to replace the RPi.GPIO module and some files (such as UDEV rules). If you are a developer or an experienced system administrator, you will not have any problems with this. In addition, we are open to patches. If you need help with this, please contact us via Discord: https://discord.gg/bpmXfz5
This project is developed on a non-commercial basis by Open Source enthusiasts. If you find Pi-KVM useful or it has saved you a long trip to check on an unresponsive server, you can support the lead developer by donating a few dollars via [Patreon](https://www.patreon.com/pikvm) or [PayPal](https://www.paypal.me/mdevaev). With this money, he will be able to buy new hardware (Raspberry Pi boards and other components) to test and maintain various configurations of Pi-KVM, and generally devote significantly more time to the project. At the bottom of this page are the names of all the people who have helped this project develop with their donations. Our gratitude knows no bounds!
If you wish to use Pi-KVM in production, we accept orders to modify it for your needs or implement custom features you require. Contact us via [live chat](https://discord.gg/bpmXfz5) or email the lead developer at: mdevaev@gmail.com
These kind people donated money to the Pi-KVM project and supported work on it. We are very grateful for their help, and commemorating their names is the least we can do in return.
