Since both the hardware and the software is opensource I expect folks to go poking around. The following should help if your going to be making changes.

If there's a code update but you don't want to re-flash the image, or if something isn't working quite right and you have figured out why. Following this procedure should allow you to change anything and everything on the Chess Challenger:

• Power off your device
• Don't run the Challenger from the battery if your making system changes.
• Flip the read/Write switch to the 'ON' position.
• Reapply power, and wait for the Pi to boot.
• Stop the chess service with this command sudo systemctl stop chess.service

At this point, assuming you followed my 'image' install instructions, you're now ready to make changes on the system or make a software update/change.

When your finished with the changes:

• Properly shut down the Pi with sudo poweroff
• Flip the read/write switch to the 'OFF' position.

There aren't any, rewrite everything if ya want, I know it can be done better. Just let me know if you make any cool changes.

Suggestions:

• Make a web based UI.
• Play over lan.
• Make an all python adaptation.
• Run a different/custom engine
• Redesign the hardware

Stockfish does support an endgame table-bases. To use an endgame table-base you need to find one first. I'm using the the syzygy 3-4-5, this can be found with google. If you want to find this table-base faster, google this hash B2E48ABBC6497F4A066E454AE4FAC73356D83313. This table-base is 938 MB, small enough to live on the Pi's sd card.

Edit the polyglot.ini file, this should be placed under the Engine section.

SyzygyPath = ~/chess/syzygy

The above directory should reflect the table-base path.