I thought I was the only one with this issue, mspaeth has a good product but his assumption is everyone is Linux saavy and will engineer their way through it. Hopefully this will help folks who bought these boards and have been collecting dust as they gave up on getting it to work.
Here is the my tutorial on getting mspaeth's usb scoreboard to work with your rasp pi.
This tutorial requires you to have a little Linux knowledge and ability to navigate in the ES file manager, if your more advanced you can use the SSH command terminal through F4. Keep in mind this is the for dummies version so linux guru's if there are any command shortcuts that can be used please let me know and i will update the tutorial.
Ensure you have Dragon's Lair setup and running via retro pie before you even attempt this tutorial.
Setup Daphne on PI3
Once you have booted Dragons Lair through ES and the files have parsed and you are able to play, then continue. Otherwise stop and troubleshoot as the rest of this won't matter. I packaged up the relevant files to save everyone the trouble, and recompiled the libvldp2.so as for some reason PI3 didn't like it.
Here are the files you will need for the tutorial.
Daphne Files
The first issue was missing libglew, and libftdi files. Unzip the attach .rar and place the libraries.tar.gz in your RPI3 /usr/lib folder.
The easiest way for me since I am Linux dumb was to place my files in the //Retropie/daphne/config folder and then copy the files to the relevant directories via file manager.
Once libraries.tar.gz is in the /usr/lib folder type this command
tar zxvf libraries.tar.gz
If successful the files should unzip into your libraries folder. You can delete the tar.gz file
Now take your libvldp2.so file and place this in the ./lib folder, this is the root library folder, you will know you are in the correct folder if you see /lib under the word "Left" in the file manager
Arrow down to the libvldp2.so and type
chmod a+rwx libvldp2.so
Hit any key then type
chown root:root libvldp2.so
If done correctly you will see a * next to the file
Navigate to /opt/retropie/emulators/daphne
Place the daphne.bin and the dlusb file in this folder, you will copy over the current daphne.bin. Back this file up if you want to restore as I have not tested this .bin on other games yet.
Also, if you do an update via ES it will restore the original daphne.bin and your scoreboard will no longer work until you replace it again with the custom .bin file
While in the same folder type
chown root:root daphne.bin dlusb
Then type
chmod a+rwx daphne.bin dlusb
Both files should be green now with * next to them
While still in this folder type
./dlusb lair (or it could be dle21 if thats the rom your using)
You should see some numbers show up and the scoreboard will have a - for lair or L-p21 for dle21
Important - If you unplug your Pi, you have to run ./dlusb lair or dle21 again prior to the command below in order for the scoreboard to initialize again. I don't know why but it doesn't remember the scoreboard state. However after you do it once, as long as you have the Pi on and load up DL it will work. This issue can be remedied with scripts, etc. to load ./dlusb first at power-up.
Now for the moment of truth, while in same folder type
./daphne.bin lair vldp -framefile /home/pi/RetroPie/roms/daphne/lair.daphne/lair.txt –usbsb
Note - can be lair or dle21, and the below is assuming you followed the file structure in the setup tutorial above.
Now if you followed directions the scoreboard will clear and 5 secs later you will see a 2 15p2 00,
The game will do its normal start up and you're good to go.