I think Mr Hamilton would be your man https://www.chess.com/clubs/forum/view/dgt3000-pi-stockfish-15-level-20-i-managed-42-moves-against-the-engine
How to load Stockfish 15 on DGT Pi 3000

It’s within pico chess version 3. I have a card with it on. I went back to the current dgt one. 0.9l I think. Version 3 is a bit annoying. I’m not good enough at chess to get any advantage from 15 ;-) Having said that, my pi works better with a card I prepared.

Here's a link to the compiled Stockfish 15 engine files: Stockfish 15
There is a Readme.txt in the zip file. Flashing a new image that has SF15 on it is the easiest and doesn't require rudimentary Linux OS skills to install (e.g., copying/editing, changing permissions of files).
Version 3 of Pico can be annoying if you leave the Tutor and Coach functions on. I turned them both off in the menu options and use the voice "Daniel" which just announces moves.
Here's an example of playing today https://youtu.be/UrZGWxqDIaE
IMHO the real advantage to version 3 is it will tell you how to correct a "set pieces" error (your board is out of synch with the game) and not just keep telling you to "set the pieces".
Note, I also replied to your comment on YouTube which has more more information on how to access the operating system on your Pi.

Thank you for your two links; the stockfish link comes back "This item might not exist or is no longer available" the youtube link is the reason I asked about the step-by-step you used to get Stockfish 15 loaded on the DGT Pi 3000. Your entire setup intrigues me. In one game, you seem to be using an app that is not Fritz. On the one game where you have a monitor of some sort, you have cables running from it into what exactly? One other question when if ever, is the HDMI connection on the back of the Pi 3000 used? Would you be willing to do a video that would explain your setup in detail? I would very much apprecatie it.

Yeah, I was laying in bed this morning asking myself if I could make this easier and I was thinking of some sort of step by step video. I'm not sure why the SF link is giving you problems... Try this one : https://1drv.ms/u/s!AtQyUnq0VT842m3GbJVvB-zrvzwu?e=ksMnFU It should just instantly start downloading when you click on the link..
The 10" monitor in front of me in the video is simply a duplication of my main monitor. The monitor is an Elecrow 10" touchscreen you can get off Amazon. You can setup duel monitors in Windows under "Displays" > Multiple monitors.
My main monitor is connected by HDMI and the cable running to the 10" monitor is DisplayPort connection. The second cable is a standard USB connection that delivers power and touchscreen capability. The resolution of the monitor is 2160.
The display you see when I use the DGT Pi is coming from the Picochess App. You get this by typing the IP address of your Pi into any browser, example: 192.168.1.18
Find your Pi IP address by looking at your list of attached devices in you router info.
The display when I'm on chess.com/lichess is just a duplication of my main display
Fritz is just the Fat Fritz 2 display...
I have a AYL mini-speaker connected to the 3mm jack on the back of the Pi for audio. However, when on the Internet, the sound is coming from the monitor speakers.
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The DGT Pi is not just a chess app. It houses a fairly powerful computer that we would have all been happy to have back in the mid-ninties. Instead of paying $3K for that power, we not pay $35. It's a Raspberry Pi computer running a Linux based operating system and is capable of running Desktops, Office knockoffs (Word/Excel ), doing email, browsing the net etc... and PYTHON! I've even built Windows forms (in C#) and ran them on it.
Running at about 1.4 gHZ. Yeah, you present day PC is running twice that fast, but 1.4 can get a lot done. The version of Linux it is running is called Raspberry Pi. It's currently in version 11 (which is what I have on my Pi) The default version of the Pi has Raspberry 7.
Here's a video link showing the desktop on a 10" monitor: Raspberry Pi Desktop
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Okay, here's the important part if you're still reading...
I knew NOTHING about accessing the Pi's OS and could remember little about Linux about 8 months ago. I just sat down and figured most of my "skills" by researching the Net on the subject matter. It's all out there... Just not in one place.
Simply start by figuring out how to access your Pi's OS from your computer. The rest will just come as your need arises. Download some Linux command "cheat" sheets and just start playing around.
1) Connect an Ethernet cable between your Pi and Router
2) Connect a monitor to the Pi with an HDMI cable
3) Login to your Pi
4) Login: pi Password: picochess (sometimes: raspberry)
*5) sudo raspi-config ---- under system enble OpenSSH
6) Enable OpenSSH in Windows (or your MAC?)
7) Now use Powershell to login to your Pi
* As long as your in raspi-config, type in your wireless connection information so you won't need the Ethernet cable connection.
Here's a pic of my current layout (Open in a new tab to see a larget image) Credit to my wife for letting me convert a 3rd bedroom into my "mancave". It allows me to close the door so she won't hear me swearing when I blunder my queen :-)

Awesome!!! Read the whole post, and I am working on setting the system up similar to your setup to include the Elecrow 10" Monitor. The first challenge so far is the Pi 3000 is not accepting a DHCP address from my network. I do Network engineering for a living, and I am puzzled by this fact. Since I have had the device, it had never displayed an IP address; no matter what device I plug it into. The port lights up when it is plugged in but never displays an IP, SMH. Thank you for taking the time to detail and photograph your setup. I will keep you posted as to the success or failure of the project. thanks again

You should be able to connect a montor to your HDMI output on your Pi and a mouse and keyboard to the USB's and just login directly to the OS. Login name should be: pi and the password is: picochess. Note on a a default raspberry OS the password is: raspberry
You can change the password by typing: sudo passwd
Then unzip the Stockfish 15 files to a USB drive, mount the USB drive on the Pi and copy the files from the USB. It takes the PC out of the equation.
You don't need a touchscreen monitor or the high resolution. Go with a 1920x1080 display and no touchscreen. It's more practical, you won't notice the resolution difference and it cost less.

Ok made some progress but ran into a small issue
1 Was able to set static IP (note NO IP is still observed on panel)
2 updated system
2 replace stockfish file per instructions of the readme file
3 edited engine.ini (only made changes related to Stockfish) reboot PI Panel shows err Engine after bootup
my question is should it be everything listed in engines.ini.example.astockf? Some items are present that are identical others such as ;move Overhead read 100 on original but 10 on example?
TIA for any help you can offer

On another note, I have the WLAN enabled as well and, as a precaution, built a new image for the Pi 3000 on a new mini SD so I can tinker. Everything was working until I copied the Stockfish 15 files and altered the engine.ini file. More than halfway there, replicating your setup. SO CLOSE!!!

Got past Err Engine (file permission issue) but can no longer select any Engine or book opening
:-( still searching for solutions

I sent you a private message asking about how you are playing the bots and having them show up in your stats. It made me question whether using a e-Board has a work around.
Ignore my basic Linux commands; I'm tying to speak to a wider audience.
Did you set a-stockf to an executable after copying it? sudo chmod +x a-stockf
The uci file is okay as copied
As you found out your need to give yourself permissions to work in the armv7l directory. From the /engines directory issue the command
sudo chmod 777 armv7l
Also sudo chmod 777 /armv7l/engines.ini (So you can edit the ini file).
Remove the old a-stockf and a-stockf.uci and *copy the new versions to /opt/picochess/engines/armv7l/
*Probably easiest just to mount a USB drive to you Pi and copy the files from there.
sudo rm a-stockf
sudo rm a-stockf.uci
sudo cp <My Source> /opt/picochess/engines/armv7l/
When you are done restore the permissions with: sudo chmod 755 armv7l
I normally replace the entire contents of the a-stockf section in the engines.ini file
There is a possibility this compiled version will not work with .9l. I suspect it was never tested with .9l after it was compiled. Scally would have only tested the compile engine with version 3.
My advice is to start with a clean image and try again. If you know how to burn and image, I think you'd be happier with version 3. In that case SF15 is already installed.
Another user stated they found version 3 annoying, but it isn't (in my opinion), if you shut off the coach and tutor in the menu options.
I'd also issue an update and upgrade command for Linux maybe a lib needs a newer version
sudo apt update
sudo apt full-upgrade

Apologize did not realize what you were asking about the bots. I need to review my stats to verify what exactly you are seeing. I think you are right; it may not be compatible with 9l. As I did some more research, I came across the picochess v3 and was going to ask you if that is what you are currently running from your earlier notes. I suspect you are. What is the best way to move to vs. three via CLI (if possible) or download vs.3 and burn a new SD?

Thank you for that; as for the bots, where are you seeing that information in my profile? I play/study using the bots on my Ipad and a couple of PC's around the house, so if I hit a setting by chance or the fact that I save some of the games in my analysis section, maybe that is it, but I am not sure.

Ok, located what it is you are seeing, and oh yeah, I have no clue how that is occurring. My goal with the bots is to learn how to play when theory is not followed or understood by my opponent online. I typically tilt against live players and bots, in some cases, help me recognize patterns or to look for patterns that are not based on theory and find better ways to adjust (stop being lazy and think truthfully)

Had to order a few mini SD cards and will try building a new image tomorrow after they arrive. Thanks again for helping do this, I will keep you posted.

Done!! Crazy easy to do. Now I am testing all the new settings and options, such as the coach and tutor. Thanks again for you all of your assistance.

Now to turn you into a Picochess V3 Power User:
If you want to use the tutor but not have it be so restrictive on what's blunder or bad move, edit the constant values at the top of the picotutor_constants.py It's in the picochess directory. I think I increased them 1-1.5
You can set your display to easier to read capital letters
When you figure out your favorite engines. Go to the /armv7l folder and edit favorites.ini and duplicate the engine.ini sections of those engines. There is no way to set favorites from the menu. However, make sure you check out the "Replay PGN" engine. By placing pgn data into the /games data files you can replay historic games, or even your own. Also you can retrieve your pgn data from this folder. Here, I use it to recreate half a game I didn't record Replay PGN demo
Run the Rod4Elo.sh file in your //home directory (./Rod4Elo.sh) to set the Elo level of Rodent IV between 800-2000. By default, they are all set to there highest level.
You now have 40 engines, 40 personalities in Rodent IV (and you can create more), Stockfish 15, many more voice choices and are running the latest version of Raspberry Pi (11 versus 7 [8-years worth of development]).
Wait until you run into a board synch issue and instead of repeatedly saying "Set Pieces", it tells you how to fix the issue. You'll know pico life is better.

I will look into that right now I am very content. playing stockfish 15 at level 4 and currently have a -1.15 as black. It appears the display indicated the Reti opening ...I am right it will now tell you the opening?

Yes...
Al Cooper (UK) visualized what he thought would be a "perfect" computer app by modifying version .9l of Picochess. Dirk Mollmann (German) spent two-years teaching himself Python and made the revisions (2 and 3). The original Pico developer was Dutch (Jean-François Romang) working for DGT. However, Picochess has had many contributors over the years. For example: Randy (Reade - Canada) recently (Feb 2022) fixed the V3 Bluetooth connection issue. Randy now maintains the Picochess versions as needed and it is distributed on the Google Groups - Picochess forum.
Does anyone have the step-by-step on how to load or upgrade Stockfish on the DGT Pi 3000?