Picochess V4 and millenium boards

[Anastasios Polichronopoulos]

Hi all, I am trying to connect my Millenium chess classics exclusive board via chess link (bluetooth) with my picochess V4 ( the fork with the eval bar) but so far I had no success. My picochess connects fine to my chessnut air and go boards.

Any ideas ?

[RandyR]

That's strange. Chesslink is the one connection that is most reliable for me. The new image incorporates the eval bar in the master branch.

[Anastasios Polichronopoulos]

It's V4.1.4 I will also try the master version and report back.

Tassos

[Aldo Bleeker]

I have connected the Millennium eOne, and The King Competition to the Raspberry Pi 5 running PicoChess 3.4, and 4.1.4/5/6, and I haven't had any problems with the bluetooth connection on the PicoChess side. I have installed PicoChess 4 on a PC running Debian 12, and 13 as well, and even on a Debian 13 VM running in VMWare Workstation Pro, and there were no issues with PicoChess connecting with the boards over bluetooth. The eOne doesn't need a ChessLink, it's actually built-in, but I just connected The King Competition with the ChessLink, PicoChess recognised the boards, and I could play games on the boards against a chess engine running on PicoChess. Mind you, all the devices are running Debian, and it can be a bit tricky getting bluetooth to run smoothly on that side, but if other boards are using bluetooth, a Millennium board should as well.

How did you install PicoChess? Did you use an image, or did you install the source on Github?

Ah, I've just noticed you mentioned a Millennium Exclusive board! Do you mean a Mephisto Exclusive board, one of the boards made in the 80's? If it's one of those, I believe you'll need some kind of module to connect it to PicoChess, I don't think you can connect a Mephisto Exclusive board directly to a ChessLink. I actually have one of these, with the MM IV chess module, and the PC Modul, that links the board to a PC, but as far as I know it only connects to a parallel port. I think the Elfacun modules can do this, but I don't have them, and have no experience with them.

[Johan Sjöblom]

Nice to hear Aldo that you have so many setups working. I have tried to make sure that both Pi aarch64 and Debian x86_64 works and to keep the architectures separated. You have maybe already noticed, but to connect to my DGT board from my Debian laptop I always run the script connect-dgt-on-debian.sh (as normal user, not sudo). I run it after each laptop start. It fakes a com port with the name expected by Picochess, com123 if I remember correctly.

-Johan

[Anastasios Polichronopoulos]

No it's not a Mephisto board is a Millenium one that connects through chesslink. So far it's working all right with versions 3.2 , 3.3 , 3.4 but not with V4.1.4.

I am downloading now the latest V4 master and I will give it a try.

Tassos.

[Randy Reade]

It could be Bluetooth is OFF (soft blocked). I saw that with Chesslink yesterday (v4 Trixie Lite image on a DGTPi). 'sudo rfkill unblock all' fixed it. 

Randy

[Anastasios Polichronopoulos]

Nope is not the bluetooth. So far I tried V4.1.4 V4.1.6 and V 3.4 ,3.3, 3.2 in 3 different Pis , two 4s and 1 3b with chesslink and both chestnut go and chessnut air.

All V3s work fine with all boards in all Pis, none is working with V4s.

Any idea as to where I should start troubleshooting?

[Randy Reade]

Sounds like the setcap command didn't work, which would be surprising. Check the picochess.log and it should show the command to run.

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[Anastasios Polichronopoulos]

This is from the logs:  ERROR ble_transport - search_board: BLE scanning failed. Failed to execute management command 'le on' (code: 20, error: Permission Denied)
2025-10-23 01:41:11.401   ERROR ble_transport - search_board: excecute: sudo setcap 'cap_net_raw,cap_net_admin+eip' /opt/picochess/venv/lib/python3.13/site-packages/bluepy/bluepy-helper
2025-10-23 01:41:11.401   ERROR   protocol - __init__: Cannot connect.

[Randy Reade]

In a terminal or via ssh, run the command: sudo setcap 'cap_net_raw,cap_net_admin+eip' /opt/picochess/venv/lib/python3.13/site-packages/bluepy/bluepy-helper

To view this discussion visit https://groups.google.com/d/msgid/picochess/d7c3f72a-1552-48d8-8f85-f6fd49af1e4fn%40googlegroups.com.

[Anastasios Polichronopoulos]

Did that already, I think it recognize the board now. I will check all the boards tomorrow  and get back to you. Thanks for the help Randy :)

[Johan Sjöblom]

Very nice to hear Anastasios that it worked after all the hard testing work you have done. Aldo had also noticed that bluepy-helper setcap path indeed was wrong in the install-picochess.sh shell script. This install script is being run at boot time if you ask for an update in Pivo V4. 

I have corrected the bluepy-helper setcap now for 4.1.6... (commit 8ad8fbe) but it did not run if you updated from 4.1.5 --> 4.1.6 because then the old 4.1.5 version install-picochess.sh updated still ran to do the update and it did not work on Trixie that has newer Python version. Next time it should work when you or anyone else runs an update in 4.16.

I think it works so that if you do a system update, then bluepy-helper loses the setcap rights. Therefore, if you do a manual system update you should run install-picochess.sh (as sudo) to make sure that all setcaps are correct... Or run it manually as per Randys suggestion above.

If you still find any problems, let me know, so that we can fix it :-)

[Anastasios Polichronopoulos]

Ok clean Installed Trixie and then picochess 4.1.6 , so far everything is ok , works with all boards fine.

Now I have to transfer all the extras from V3.4 like engines etc.

Thanks everyone for your help.

[Johan Sjöblom]

Nice to hear.

You can copy engines yourself or try the new system to get the latest engines for V4 as described in this post

https://groups.google.com/g/picochess/c/TzY_UEVtrjQ/m/fW0DfzgwAAAJ

[Anastasios Polichronopoulos]

Opps to fast to talk, Trixie did an update and now picochess service doesn't start at boot (  manually either).
Am I the only one cursed in here?

[Johan Sjöblom]

After any system update that has been done you need to run the install-picochess.sh again:

> cd /opt/picochess

>sudo ./install-picochess.sh

That should install picochess properly again... Hope that helps?!

-- Johan

[Anastasios Polichronopoulos]

Done that already but it did not help, so I deleted everything about picochess and start from the beginning.

I will post when I am done.

Tassos

[Anastasios Polichronopoulos]

Ok found the problem , if VNC is enabled for some reason picochess service can not run.

Tassos

[Johan Sjöblom]

Good testing!

Did you check the journal info for the failed picochess start.

> journalctl -u picochess.service

To view this discussion visit https://groups.google.com/d/msgid/picochess/711a8072-6df1-44f9-ad62-77869dad0b1bn%40googlegroups.com.

[Aldo Bleeker]

I've installed and set up a clean Trixie image with Pi Imager on a Raspberry Pi 5 with a 256 GB SATA SSD. Then I ran sudo raspi-config to expand the storage space, switch to X11, and pulseaudio, and enable the VNC interface (VNC is working without having to install VNC Server). After I got Trixie running, I updated it, and installed the latest PicoChess 4.1.6 by running the script that I had download from Johan's GitHub, with sudo /opt/install-picochess.sh. There were no issues. After rebooting I checked the picochess service with sudo systemctl status picochess. It was enabled, but inactive, and dead. Unfortunately executing sudo systemctl start picochess didn't work, it hung and didn't finish, not even after waiting quite a while. The log didn't have any information, but that might have been because the service hadn't started. Running install-picochess.sh again hasn't fixed the issue. I've also installed the official image again, but the same happened. I've installed Randy's latest image, and on that one picochess.service finishes correctly.

It may have been waiting for something that I should have installed, or started, but I can't think of anything. Doing this on Debian, or even a virtual machine, is working fine. Does anybody have any suggestions?

[Johan Sjöblom]

I will test the same tomorrow. The only quick thought I have now is that VNC confuses the access to DISPLAY, and pico either tries to start too early, or does not find the display.

To view this discussion visit https://groups.google.com/d/msgid/picochess/8f743516-ae1f-4286-a91e-088aa182842en%40googlegroups.com.

[Aldo Bleeker]

I had missed Tassos' post, and read it just now. Enabling VNC is the cause of this issue?

Can we still use VNC? Would not enabling the VNC interface, and installing VNC Server work?

Aldo

[Johan Sjöblom]

At this point I am just guessing. Lets find out exactly why it does not work and then fix it. I am sure we can make vnc work...

To get more info:

sudo journalctl -u picochess.service -b -n 50

I will try to reproduce the issue myself tomorrow...

I wonder if there is any reason why VNC and X would behave differently on Trixie... or maybe this is a problem also on Bookworm?

On Trixie it could be tightened security or wrong starting order of picochess.service?

I guess it cannot be that easy that picochess.service should wait for X graphics?

[Unit]

After=graphical.target

Wants=graphical.target

I never use VNC on picochess, I just use the web interface and ssh... I need to test what happens.

To view this discussion visit https://groups.google.com/d/msgid/picochess/79005c4f-b59a-49aa-8357-7fef29fb4350n%40googlegroups.com.

[Aldo Bleeker]

I've just installed a new Trixie image, and PicoChess 4.1.6 to the RPi 5, and I can confirm that without VNC, connecting with SSH, PicoChess is working great.

Tassos is right, awesome discovery!

Aldo

[Randy Reade]

Unless something has changed from RPiOS in the last couple of weeks, the VNC they released is WayVNC which can't be enabled unless you are in Wayland. If you install VNC Server from RealVNC, under X11, then enable VNC, you'll be running the X11 version.

Also, PicoChess technically doesn't need a display server. It will run on the Lite image.

What does 'systemctl status picochess' show when it doesn't work? I assume you are using a monitor and not running headless.

I also cannot test at the moment.

Randy

[Anastasios Polichronopoulos]

Same as Aldo , was showing "sudo systemctl status picochess. It was enabled, but inactive, and dead" for some reason it could not start the service at all , I tried manually  lots of times, start , restart etc but nothing.

Tassos

[Johan Sjöblom]

First of all, thanks Tassos again for a great testing effort :-)

I downloaded Randy's latest "clean" V4 Desktop image and started it in a Pi 4B. Before doing any updates whatsoever, no Trixie, no System updates the status is the following:

- both picochess and realvnc works

Reason most likely being that Randy seems to have installed the realvnc-vnc-server which is for X11. If you use the built in VNC server it will be the Wayland VNC and that one does not work. How to check the difference?

> ps -ef | grep -i vnc

If you see /usr/bin/vncserver-x11-serviced you have the correct one. The Wayland wrong one would show something like /usr/bin/wayvnc and this one is wrong!

The X11 vnc server binary is here:

/user/bin/vncserver-x11-serviced

The service process file that starts it is found here, not sure if you need to write it yourself or if Randy has written it for us.

/usr/lib/systemd/system/vncserver-x11-serviced.service

to install this X11 VNC I think Randy must have used something like this:

> sudo apt install x11vnc

Also check the value of this variable, it should be X11 if everything is ok:

>echo $XDG_SESSION_TYPE

it should output: x11

to make sure your system is not running Wayland vnc server you can do something like this:

> sudo systemctl stop wayvnc
> sudo systemctl disable wayvnc

Or you can remove or edit the service /etc/systemd/system/wayvnc-control.service

By-the-way... It seems the wayvnc is a python program!?

-- Johan

[Aldo Bleeker]

Last time when I had installed Trixie and configured it with raspi-config, I had at that time enabled VNC in the interfaces. I'm assuming it was running Wayland at the time, and enabling VNC then may well have installed Wayland-VNC. After rebooting, VNC was working, but picochess.service was hanging. Its status then was enabled, but it was inactive, and dead.

This time however, Tassos had found out that there was an issue with VNC, so I ran raspi-config without enabling VNC. I enabled X11, and pulseaudio, and rebooted the RPi. I then updated Trixie, and ran install-picochess.sh. This time picochess.service was enabled, active and running, confirming there's some kind of issue with VNC. I enabled autostart, and tested it. PicoChess came up and ran without issues. I then wanted to see what would happen when I enabled VNC, so I used SSH to run raspi-config. After rebooting just to be sure, I noticed that this time the status of picochess.service still was active, and running, but PicoChess was only displaying a completely white screen. I waited a while, and to my surprise PicoChess started properly, and VNC was working as well!

I now believe the difference is that the RPi was running X11 at the time I installed VNC. This probably resulted in installing the X11-version of VNC, so all was well, and everything is now up and running.

I've now read Johan's latest post as well, and the result of the commands he suggested is that the RPi is running X11, and vncserver-x11. Awesome job, guys!

BTW, I noticed prompts about the key ring. Apparently, this is caused by autologin, which I had configured as well. If you see the prompt, enter a blank password and confirm it. This will satisfy the key ring, and stop the prompts.

[Johan Sjöblom]

Nice, I think we have nailed this one. Some minor notes:

• The key ring can be triggered from many programs but most likely its Chromium web browser that triggers the keyring prompt. I was surprised by the popup too as I was not sure which program caused it. My bet is on the web browser, but it could be any program that needs to store passwords, manage SSL certificates, encryption keys or managing google account sync tokens.
• Even if picochess would start after a while under Wayland VNC I think we would find that the real problem is with mame artwork. As Randy pointed out in a discussion the problem is the xdotool. And the long term solution to this is that we port picochess to be able to use Wayland instead of X11.   ( https://github.com/JohanSjoblom/picochess/discussions/120 ) 
• And finally, how to help other users? Well I will put a warning in the readme file in github for people installing on a stock pi image. I could also "print out" a warning if the  $XDG_SESSION_TYPE variable is not X11. If I do that at the end of the picochess installation it might save someone else this trouble.

BR, Johan

[Randy Reade]

There's also some X11 related commands when starting kiosk mode. And the script (in my images) will fail under Wayland, giving no browser.

The switch to Wayland should be fairly easy.

Randy