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HermannSW
Posts: 6257
Joined: Fri Jul 22, 2016 9:09 pm
Location: Eberbach, Germany

Re: Pi400 KVM switch

Wed Dec 06, 2023 9:43 pm

OK, no more self healing.
So the original plan was to replace the Pi400 keyboard with the keyboard from Raspberry keyboard and hub.
But I would prefer to replace the Pi400 with Pi500 and keep the Raspberry keyboard and hub working.
While several discussions suggested that there will be a Pi500, it is likely not available before H2 2024.

I did investigate KVM devices on amazon.com, and learned that the simplest and cheapest have 2 USB connectors for keyboard and mouse and VGA for 2 computers.

Next simple and cheap are those for two computers with HDMI. I found and bought this one for 21.50$ only with Amazon prime:
https://www.amazon.de/dp/B0B13XBKX9?th=1
It arrived today. Has 4 USB-A connectors for keyboard/mouse/..., two HDMI-in and two USB-B out with matching cables to connect to both computers. And finally two HDMI cables for connecting both computers, a switch to toggle computers and two leds indicating which computer is active. Product allows for 4K@30Hz and is for USB 2.0 [which is OK for (Rsapberry) keyboard and mouse].

I use my laptop elevated, and installed all on top for testing first:
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IMG_20231206_175443_MP.10%.jpg (19.82 KiB) Viewed 1573 times
It directly worked, switching between Pi400 and laptop had no problems — wonderful.

Then I did stuff all cables below the laptop with both computers powered off.
And the problems begun. It took hours to get it working again, changing order of powering, which is PC1 and which is PC2, changing cabling, ...

But I was sure that I really had it working initially, so after eliminating all other problems, I focused on display resolution.
My HDMI display has 1920x1080, and the Pi400 as well.
My laptop has 4K builtin display, but I told it to use single external display with 1920x1080.
Did not work.
Then I tried "Mirror" to display 1920x1080 on both screens, and that did work.

While others don't like Raspberry keyboard, I do.
I used Pi400 as KVM switch for more than 2 years now and was happy to control Pi400 as well as laptop with Pi400 keybaord.
The 2 computer hardware KVM is good enough for me, and 21.50$ is more than OK to me.
Now again I have much free space; I did fixate the Raspberry keyboard cable with 3 drops of superglue on the keyboard hub.
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IMG_20231206_220150_MP.20%.jpg (62.11 KiB) Viewed 1573 times
https://github.com/Hermann-SW/RSA_numbers_factored
https://stamm-wilbrandt.de/GS [304+402+536fps]
https://hermann-sw.github.io/planar_graph_playground
https://github.com/Hermann-SW/Raspberry_v1_camera_global_external_shutter
https://stamm-wilbrandt.de

User avatar
HermannSW
Posts: 6257
Joined: Fri Jul 22, 2016 9:09 pm
Location: Eberbach, Germany

Re: Pi400 KVM switch

Fri Dec 08, 2023 11:25 pm

One last change to the setup — after I received my Pi5 today I will move the Pi400 with defect keyboard somewhere else for remote access.

For the Pi5 I measured the same 2.2x single threaded / 3.6× multithreaded speedup over Pi400 with Passmark benchmark others reported:
viewtopic.php?p=2152690#p2152690
I am impressed by the tiny and quiet active cooler:
I did run "speedtest --cpu 4" and in other window "watch vcgencmd measure_temp", and after 25min temperature was still <61°C.

I bought the Pi5 for getting at least 2.2× speedup for wolframscript computations
(because Mathematica/wolframscript are free for Raspberry computers):
viewtopic.php?p=2166024#p2166024
[PARI/GP CAS (Computer Algebra System) I use mostly is free on all platforms, and open source in addition]

I first had mixed feelings about bookworm, but the bad experiences were caused by a bad SDcard.
I just flashed Bookworm onto new SDcard, and everything is wonderful, with superfast browsing.
Someone reported that I can get another 25% single threaded speedup over Pi400 (2.75×) by 3000Mhz overclocking.
I will definitely test that.

So from now on, until Pi500 will GA, my KVM setup allows to switch between laptop and Pi5:
IMG_20231208_235331_MP.20%.jpg
IMG_20231208_235331_MP.20%.jpg
IMG_20231208_235331_MP.20%.jpg (57.45 KiB) Viewed 1467 times
https://github.com/Hermann-SW/RSA_numbers_factored
https://stamm-wilbrandt.de/GS [304+402+536fps]
https://hermann-sw.github.io/planar_graph_playground
https://github.com/Hermann-SW/Raspberry_v1_camera_global_external_shutter
https://stamm-wilbrandt.de

User avatar
HermannSW
Posts: 6257
Joined: Fri Jul 22, 2016 9:09 pm
Location: Eberbach, Germany

Re: Pi400 KVM switch

Sat Dec 09, 2023 9:09 pm

I have a wireless Logitech K400+ keyboard, that is cool if wireless is needed. But I like the Raspberry keyboards more, and since my Pi400 keyboard is bad now, and Raspberry keyboard and hub is permanently used for my KVM from now on, I just bought another keyboard plus USB hub. Because the other display, the USV it sits on and trackball are black, I ordered (German) black keyboard. Works nicely, and looks cool. I use that 2nd working place when working with other PIs or miniPC.
IMG_20231209_204553_MP.15%.jpg
IMG_20231209_204553_MP.15%.jpg
IMG_20231209_204553_MP.15%.jpg (33.15 KiB) Viewed 1317 times
https://github.com/Hermann-SW/RSA_numbers_factored
https://stamm-wilbrandt.de/GS [304+402+536fps]
https://hermann-sw.github.io/planar_graph_playground
https://github.com/Hermann-SW/Raspberry_v1_camera_global_external_shutter
https://stamm-wilbrandt.de

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