31 KiB
Community FAQ
Index
- Can this be used for gaming? Why not?
- Can this do 4K?
- Does PIKVM support sound
- Why so much latency between the screen and target?
- Is Pi-KVM an OS or its own Distro?
- Why are you using Arch Linux?
- Can I power the Pi via POE?
- Do I need a power splitter? Why do I need one?
- I can't get the KVM KB to work on my ZeroW!
- Can I use a KB on my ZeroW?
- Can you have the pi-kvm(RPi4) connected along with a monitor?
- Wouldn't it be good to have different hostnames for your multitude of pi-kvms?
- I want to do something not related to Pi-KVM
- Can this be used in any other distro’s like Rasbian? Run this in a Docker?
- Can you switch from USB to CSI or from CSI to USB?
- My Pi keeps disconnecting from my wireless! What do I do?
- I want a static IP!!
- Why do I keep getting a different IP?
- HELP! I can't find the IP on the ZeroW/RPi4
- Help! I ran out of room!
- Can you connect a camera to this and still make pikvm functional?
- I have a question that is not answered here!! Now what?
- HELP! Something isn't working!!
- HELP! I am getting a 503 error when I try and access the main KVM page!
- Can you use an iPad on PiKVM?
- Can I use RealVNC/Guacamole to connect to PiKVM?
- How do I add my own SSL cert?
- How do I emulate various USB devices on the target machine?
- Things to do after initial install
- Can I have a RW FS all of the time?
- Can you run a desktop on pi-kvm?
- Troubleshooting
- Common Commands for troubleshooting Pi-KVM
- Common ARCH commands
- Common wifi commands
- Bootup/power issues
- PiKVM Complains about low power warnings
- USB Video Capture Issues
- HDMI-CSI Capture issues
- Misc stuff
- Useful links
Can this be used for gaming? Why not?
- ❗No❗, the max bus lanes the Pi provides, is not enough to support anything faster than 30 FPS. Your better off looking at other solutions for this.
- ❗No❗, PiKVM does not capture and transmit audio at this time. The developers have indicated that this may be available for the v3 hat at some point in the future, but it is not a priority for development at this time.
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Can this do 4K?
- For the CSI Bridge, ❗No❗. there is not enough bandwidth in the CSI bus for that much data. 1080p50 will max out the bandwidth
- For the USB capture devices: Technically yes, but they will downsample to something smaller to meet the usb2.0 bandwidth limitations, so the source may be 4k, but the stream will not.
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Does PIKVM support sound?
- At this time sound is not supported on any platform however, once sound is implimented, it will only be available for v3. Due to a hardware bug in v0/v2 capture devices, sound may or may not work.
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Why so much latency between the screen and target?
- capture device+compression+network+decompression+external network(if applicable)
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Is Pi-KVM an OS or its own Distro?
- Yes and No, Other than the some repacking and patches, its heavly based off an existing Arch Linux ARM.
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Why are you using Arch Linux?
- The developer was more familiar with Arch Linux so this was chosen as the base operating system. As a Linux distribution, it has more in common than not with other distributions.
As an appliance, users are not expected to interact with the host operating system often, if at all. There are some distribution-specific differences, by default networking is done using either systemd-networkd or netctl but NetworkManager can be used as a replacement if one prefers.
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Can I power the Pi via POE?
- Yes! But you will still need to ensure you isolate the 5v connection between the Raspberry Pi and host PC to prevent backpower issues that can cause instability or damage to either the host PC or the Pi. Power/Data cable + usb power blocker would work. Please see Variant #1 in the main getting started page for details.
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Do I need a power splitter? Why do I need one?
- Yes for RPi4, Yes and No for ZeroW - Yes if you want dedicated power, otherwise No
- Yes, otherwise you could back power the pi and or the target
- You can get a Y cable from amazon and mod one of the leads - Please see getting started guide - or see non modding of Y cable
- You can also get a power splitter board from Tindi or PiShop (Links provided below)
- If you have the v3 HAT - This is built in
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I can't get the KVM KB to work on my ZeroW!
Make sure that you did NOT modify your config.txt file, this is the default:
# See /boot/overlays/README for all available options
initramfs initramfs-linux.img followkernel
hdmi_force_hotplug=1
gpu_mem=64
enable_uart=1
dtoverlay=tc358743,i2c_pins_28_29=1
dtoverlay=disable-bt
dtoverlay=dwc2,dr_mode=peripheral
Ensure that you have the cable(Needs to support both power/data) plugged into the right port, the one closest to the mini HDMI is the correct port
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Can I use a KB on my ZeroW?
- Yes but kb/mouse passthrough will not work. Its one or the other - This is especially true if you use an addon that requires the below to change.
- edit
/boot/config.txt
- Host mode - Comment out dtoverlay=dwc2
- Passthrough mode - Uncomment out dtoverlay=dwc2
Can you have the pi-kvm(RPi4) connected along with a monitor?
- A community member has had success with the following: https://www.amazon.com/gp/product/B08DQWLXF1
- Some Alternitives
- If you have two outputs, you may be able to use screen mirroring from the OS but not BIOS
- If you have one output or need access from both a local monitor or Pi-KVM at boot time, one of the following options may work:
- Passthrough HDMI capture devices (sometimes referred to as a loop capture device). The Elgato devices DO NOT WORK! Look for Linux OS support when choosing a device, the expected price range is about $35-$70 US.
- Depending on your capture device, an HDMI splitter may work but will need what is called an EDID (Extended Device ID) generator, the monitor and capture device both generate EDID so the splitter must produce its own separate EDID for the host.
- Look for HDMI splitters - although there have been reports that these are not stable
- Please use the search function in Discord, some users have had sucess in getting this to work but your mileage may vary
- The better solution is to capture the stream in a dir and then use VLC to stream to that capture on another computer. This will result in fps loss.
Wouldn't it be good to have different hostnames for your multitude of pi-kvms?
Yes! And it's easy to do! Using a SSH session or the web terminal:
- Make sure you're
root
, if you're not root use thesu
command to become root - Enter read write mode of the PiKVM by executing the
rw
command - Execute:
hostnamectl set-hostname yournewhostname.domain
- Optional: Edit
/etc/kvmd/meta.yaml
to alter the displayed hostname in the web UI - Reboot the pikvm
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I want to do something not related to Pi-KVM
- It's recommended that you review Arch documents related to what you want to do, while there are several folks in discord who can help, there is no obligation...they do it for the feels. So if you don't get an answer within the time frame you are looking for, it's advised you start google searching for what you want.
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Can this be used in any other distro’s like Rasbian? Run this in a Docker?
- Not at this time, maybe in the future
Can you switch from USB to CSI or from CSI to USB?
- Officially, no. Unofficially yes. Please visit this site and grab the platform-switcher.sh script
Directions:
- Place script in the root dir
- Make a
custom-override.yaml
file - NEEDS to adhere to proper spacing, please see kvmd -m for proper formatting
kvmd:
streamer:
forever: true
cmd_append: [--slowdown] # for usb-hdmi only so that target PC display works w/o rebooting
### this section is for use with webrtc/h.264 -- up to resolution: line
h264_bitrate:
default: 5000
cmd_append:
- "--h264-sink=kvmd::ustreamer::h264" # requires gpu_mem=256 in /boot/config.txt for usb dongle
- "--h264-sink-mode=0660"
- "--h264-bitrate={h264_bitrate}"
- "--h264-gop={h264_gop}"
### Optional
#resolution:
# default: 1280x720 # default resolution I use in webui - usb-hdmi only
- Make a
config.txt.usb
file
initramfs initramfs-linux.img followkernel
hdmi_force_hotplug=1
gpu_mem=256
enable_uart=1
dtoverlay=disable-bt
dtoverlay=dwc2,dr_mode=peripheral
#dtparam=act_led_gpio=13
# SPI (AUM)
#dtoverlay=spi0-1cs
# I2C (display)
dtparam=i2c_arm=on
# Clock
#dtoverlay=i2c-rtc,pcf8563
- Make a
config.txt.csi
file
initramfs initramfs-linux.img followkernel
hdmi_force_hotplug=1
gpu_mem=128
enable_uart=1
dtoverlay=tc358743
dtoverlay=disable-bt
dtoverlay=dwc2,dr_mode=peripheral
dtparam=act_led_gpio=13
# HDMI audio capture
dtoverlay=tc358743-audio
# SPI (AUM)
dtoverlay=spi0-1cs
# I2C (display)
dtparam=i2c_arm=on
# Clock
dtoverlay=i2c-rtc,pcf8563
- Place all files in the same dir as the platform-switcher script
- Run
chmod +x platform-switcher.sh
- Run
./platform-switcher.sh
- Follow the directions that are printed out, Eg: ./platform-switcher.sh -f
- Now you can switch back and forth between usb and csi, please note there is an almost 2 min delay before the portal becomes active.
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My Pi keeps disconnecting from my wireless! What do I do?
- You can try the following: Edit "/etc/conf.d/wireless-regdom" and look for your region and uncomment it. Example: WIRELESS_REGDOM="US"
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I want a static IP!!
- You can configure systemd-networkd for a static address for ethernet NIC. Config file is /etc/systemd/network/eth0.network
- For wireless adapter, config file is /etc/netctl/wlan0-
- See pikvm/wifi_config.md at master · pikvm/pikvm · GitHub for details on how to get basic wireless config with DHCP going. Afterwards, you’ll need to edit the /etc/netctl/wlan0- file changing the IP=dhcp line with the following lines updated to reflect your network:
For /etc/systemd/network/eth0.network
[Match]
Name=eth0
[Network]
Address=192.168.X.XXX/24
Gateway=192.168.X.X
DNS=192.168.X.X
DNS=192.168.X.X
For /etc/netctl/wlan0-<wifiname>
IP=static
Address=('192.168.X.XXX/24')
Gateway=('192.168.X.X')
DNS=("192.168.X.X 1.0.0.1 1.1.1.1")
- You can also reserve the IP in your dhcp server (Quicker)
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Why do I keep getting a different IP?
- You can do 2 of the following actions:
- Add to, /etc/systemd/network/eth0.network
[DHCP]
ClientIdentifier=mac
- OR reserve the DHCP ip in your server/router
HELP!! I can't find the IP on the ZeroW/RPi4
- Open a browser and type: pikvm, still doesnt work?
- Use the FING mobile app to scan your network, its free
- Install Angry IP scanner, tools/preferences/Display results in the results list/Select Alive hosts, modify IP range, hit start
- Using FF, navigate to https://pikvm (Depends on your network if this actually works, in most case's it "should" work))
- The below commands will verify that your Pi on on your network
Linux: arp -a | grep below is a list of MAC's for Raspberry Pi
B8:27:EB:xx:xx:xx B8-27-EB-xx-xx-xx B827.EBxx.xxxx
DC:A6:32:xx:xx:xx DC-A6-32-xx-xx-xx DCA6.32xx.xxxx
E4:5F:01:xx:xx:xx E4-5F-01-xx-xx-xx E45F.01xx.xxxx
Windows Power shell: arp -a | findstr 'b8-27-eb' (Replace with the above, all lower case)
- For older flashed images you can do the following on the RPI4, ZeroW edit it when you edit WiFi info
- Open web terminal and go to root,
rw
thennano /etc/issue
- add
IP: \4
- Once you reboot, you will now see the IP in the upper left
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- Open web terminal and go to root,
Help! I ran out of room! What now?
- You’ve cached package updates you no longer need.
- Enter read/write mode by executing rw as root
- Execute the following as root to clear the package cache
rm -rf /var/cache/pacman/pkg/*
- Exit read/write mode by executing ro as root
- You can also use gparted to resize partitions without "losing data", although there is a chance this may delete all of your data
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Can you connect a camera to this and still make pikvm functional?
- Yes, any cheapo webcam can be used in place of the usb dongle, please use the usb image
- A PiCam will NOT work
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I have a question that is not answered here!! Now what?
- Please look at all pins on Discord and/or ask in #chat
- Please look in #news on Discord
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HELP!! Something isn't working!!
- What was the last thing or most recent thing you did? Did you undo it?
- Did you change a file? Did you back it up before changing it?
- Did you hook this to anything else? If not why not?
- Did you try different cables?
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HELP! I am getting a 503 error when I try and access the main KVM page!
- This is due to a bad line in your yaml file, here are some steps you can make to help in the future.
- Run
kvmd -m
, this will display ALL kvmd settings, you can compare to your own. Make sure you are not doubling up on child/sub-child entries. - Remember you need 4 space per child and 4 additional for each sub-child
- Make a .nanorc file and populate it with the following: set linenumbers is optional
set linenumbers
set tabsize 4
set tabstospaces
- Now re-edit your override.yaml file and just use tab to get the right spacing, you might need to delete the current leading "spaces" to ensure proper formatting
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Can you use an iPad on PiKVM?
- Yes, with the correct hardware you can control an iPad
- Yes, activate VNC and use JUMP app(Full featured but more expensive), or bVNC(Not recommended, lack luster features but cheap). RealVNC does NOT work
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Can I use RealVNC/Guacamole to connect to PiKVM?
- No, RealVNC is not a real vnc so will not work
- No, Guacamole supports a minimum of VNC capabilities and is fundamentally incompatible with Pi-KVM (for example, it does not support JPEG for video compression).
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How do I add my own SSL cert?
- If you have a certificate(❗Making a cert falls outside the scope of PIKVM - Please reference Linux documentation❗), replace the public key in /etc/kvmd/nginx/ssl/server.crt and private key in /etc/kvmd/nginx/ssl/server.key and restart the kvmd-nginx service.
- It should look like the following:
cd /etc/kvmd/nginx
cat ssl.conf (Expection of what's inside the file)
ssl_protocols TLSv1.3 TLSv1.2 TLSv1.1 TLSv1;
ssl_ciphers "EECDH+AESGCM:EDH+AESGCM:AES256+EECDH:AES256+EDH";
ssl_certificate /etc/kvmd/nginx/ssl/server.crt;
ssl_certificate_key /etc/kvmd/nginx/ssl/server.key;
add_header Strict-Transport-Security "max-age=31536000; includeSubDomains" always;
How do I emulate various USB devices on the target machine?
By default this is what is set:
otg:
manufacturer: Pi-KVM
max_power: 250
product: Composite KVM Device
product_id: 260
serial: CAFEBABE
udc: ''
user: kvmd
vendor_id: 7531
You can change how this is displayed with the following example:
nano /etc/kvmd/override.yaml
otg:
manufacturer: Corsair
product: Corsair Gaming RGB
serial:
vendor_id: 6940
product_id: 6973
Use the following USB Data Base to get the desired devices: https://the-sz.com/products/usbid/
or https://devicehunt.com
❗NOTE❗ You may need to include 0x0
in the id string's for it to work properly.
- Example:
vendor_id: 0x06940
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Things to do after initial install:
- Fix date: 'timedatectl list-timezones' then 'timedatectl set-timezone America/Los_Angeles' (Change to your location)
- Update Pi-KVM, follow #news on Discord for instructions
- Setup a NFS share to give read/write storage on the read only pikvm
- Note: this does assume you already have an NFS server on your network and accessible to pikvm
- Source https://linuxhint.com/install_configure_nfs/
pacman -S nfs-utils
showmount -e 192.168.1.XXX
mount -t nfs 192.168.1.XXX:/volume1/Data /mnt/Data
nano /etc/fstab
Add To the bottom of the file
192.168.1.XXX:/volume1/Data /mnt/Data nfs auto,rw,soft 0 0
Can you run a desktop on pi-kvm?
- Yes BUT, its not recommended as this OS should be used in RO and it will need RW enabled all of the time. Instructions here
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Can I have a RW FS all of the time?
- YES! BUT its not recommended, however this is what you can do:
nano /boot/cmdline.txt
&nano /etc/fstab
Change ro to rw and change the /boot line from ro to rw
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Troubleshooting
-
❗It is expected that you are aware of basic networking while working on this project and that you have read up on the project prior to going to Discord❗
- Do you know the IP?
- Can you ping the IP?
- Did you swap cables?
- Did you swap the eth port to a known working eth port?
- Do you have access to another router or switch?
- Did you change ports on the router/switch?
- RPi4 - Did you hook up a monitor? Once logged in, can you ping to your gateway? Other IP's on the same network?
- Did you connect a monitor to the target? Does it work?
- Did you connect the PIKVM to the target directly? Does it work?
-
Reboot target
-
Try default image, do not update and test
-copy/paste into a file, call it pi-info.sh, chmod +x pi-info.sh, ./pi-info.sh Same script is located here
#!/bin/bash
uptime
TMPFILE="/tmp/pacmanquery"; /bin/rm -f $TMPFILE
pacman -Q | awk '{print $2, $1}' > $TMPFILE
chmod go+w $TMPFILE
pistat && echo
printf "%-18s\t%s\n" "Version" "Package-Name" "----------------------" "-----------------------------"
PACKAGES="firmware bootloader kvmd ustreamer nginx wpa wireless"
for PKG in $( echo $PACKAGES ); do
printf "%-18s\t%s\n" $(grep $PKG $TMPFILE | sed 's/-[1-9]//g')
done
dmesg | grep tc35
- CSI
dmesg | egrep '1-1.[245]|uvc'
- USB
systemctl status kvmd
systemctl status kvmd-otg
-
hint: look at kvmd-platform line of the output... make sure it matches the image they expect for the capture device and platform
-
Keyboard/Mouse icons orange? Try a different cable (ALLOT are power only), try a different usb port
-
Should see the following if everything is in place
ls -l /dev/kvmd
lrwxrwxrwx 1 root root 5 Apr 5 21:33 /dev/kvmd-hid-keyboard -> hidg0
lrwxrwxrwx 1 root root 5 Apr 5 21:33 /dev/kvmd-hid-mouse -> hidg1
lrwxrwxrwx 1 root root 6 Mar 15 09:07 /dev/kvmd-video -> video0
Common Commands for troubleshooting Pi-KVM
journalctl -u kvmd
journalctl -u kvmd-vnc
journalctl -u kvmd-ipmi
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Common ARCH commands
- search -
pacman -Ss 'the thing'
- install -
pacman -S 'the thing'
- remove -
pacman -Rscnd 'the thing'
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Common wifi commands
-
iwconfig
manipulate the basic wireless parameters -
iwlist
allow's you to initiate scanning and list frequencies, bit-rates, encryption keys… -
iwspy
displays per node link quality -
iwpriv
allow's you to manipulate the Wireless Extensions specific to a driver (private) -
Some examples
iw dev wlan0 scan | egrep "signal:|SSID:" | sed -e "s/\tsignal: //" -e "s/\tSSID: //" | awk '{ORS = (NR % 2 == 0)? "\n" : " "; print}' | sort
iwlist wlan0 scan | egrep "Cell|ESSID|Signal|Rates"
iwlist wlan0 scan
iw wlan0 info
Bootup/power issues
- PiKVM won’t boot past “rainbow” screen
- Are you plugged into the right HDMI port? Needs to be the one next to the power for RPI4
- Have you reflashed your SD card?
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PiKVM Complains about low power warnings
- Are you using a
proper
power supply? Not one you hacked together? - Some USB power bricks advertise 5V @ 2.1A or higher, but can’t deliver consistent 5V. Best to use rpi foundation recommended power supplies
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USB Video Capture Issues
- Make sure this is a capture card and not an adapter (HDMI->USB)
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HDMI-CSI Capture issues
- Have you reset the Target PC?
- Are you sure it's a bridge and not an extender? There is a difference
- Did you make sure it's plugged into the right port? It needs to say Camera NOT Display
- Did you try another ribbon cable?
- Did you reseat the ribbon cable?
- Is the ribbon cable facing the right way? Needs to be towards the PCB (Green or Black)
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Capturing video from non HDMI sources
- TBD
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Keyboard/Mouse Issues
- TBD
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OTG Keyboard/Mouse Connection
- TBD
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Arduino Keyboard Mouse Connection (UART wiring)
- TBD
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Arduino Keyboard/Mouse Connection (SPI Wiring)
- TBD
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ATX Control Issues
- TBD
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HDMI KVM Interface Issues
- TBD
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Connection issues
- TBD
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Misc stuff
- Fully working example of a Pi4 USB-HDMI KVM attached to AIMOS 4-port HDMI KVM switch (8 port is on AliExpress), with keyboard hotkey switching between inputs, and mass storage media emulation on a Pi Zero W https://docs.google.com/document/d/1wgBZHxwpbJWkJBD3I8ZkZxSDxt0DdNDDYRNtVoL_vK4
- Useful scripts that enhance the Pi-KVM's functionality
https://pastebin.com/u/srepac
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Useful links
- https://www.tomshardware.com/how-to/kvm-over-ip-raspberry-pi - Very good article on PI-KVM setup
- Current 3D cases that support the various Pi-KVM hardware configurations:
https://www.thingiverse.com/search?q=pi-kvm&type=things&sort=relevant
https://www.thingiverse.com/thing:4799094
As of March 2021, Out of Stock or hard to get, all have exceptionally LONG shipping dates - Could try AliExpress or get a usb2hdmi dongle from Amazon, please ask or search in Discord for the best known working one
Ezcoo KVM - Goes out of stock frequently
CSI2-HDMI bridge w/ TC358743XBG chip - Goes out of stock freqently
Alternative names for the same devices:
Tiamu Sling Yazan Ningwang Essenc Geekworm
Fauge Haudang AKAT Docoop Katigan Lyusa (recommended by mdevaev)
LNIMI cherrypop Lopbinte Uang Tuneway Mustwell
Facibom Binchil Cobeky Ctzrzyt Davitu
- Community recommended USB capture card
- Community recommended Loop device that allows Monitor+PiKVM
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