Some of us got our start in building virtual pinball machines before getting into building Homebrew pinball machines.
In the virtual pinball world, pc's drive TV screens emulating tables via pinmame and other software. A series of modules can also drive solenoids and shakers to emulate the real pinball experience.
One such piece is the back glass. This component consists of the scoring display (7 Segment, DMD, etc), lamps, flashers, and sound.
In the home brew world, beginners may choose to employ simple solutions such as 2 or 4 line LCD displays and push the score and ball & credit via it.
Lets face it when your learning the craft you take baby steps to learn.
I took a different route in my learning experience. I used a raspberry pi and python to replicate a back glass of my game.
Let me walk you thru it.
The Raspberry pi is receiving state information via serial data from an arduino mega (Score, Credit, Ball, Back glass lamps state, Sound events).
The pi reads the data via the python program and paints the data onto the back glass screen or plays the desired sound event.
This inexpensive method allow the budding Home brew builder the opportunity to explore building a simple backglass environment.
It addresses sound, score display, lamp wiring and attract issues. Plus adding future animation displays and events to the backglass over time.
Rest assured there are other ways to do this thing. You may choose to use a separate wave trigger board for sound events, and 6 7 segment displays for the 4 score displays and credit and ball display, or maybe use a DMD display, and have multiple wires to your backglass lamps. This is a daunting task for beginner homebrew folks. Perhaps for this very reason you see that beginning projects don't even have a backglass connected.
I will post a youtube video of the backglass and share the python code, which I have running on my raspberry pi 3.
Basically is python 2.7 and pygame talking serial to the arduino.
Hopefully by sharing this, beginning home brew builders have an alternative choice to constructing back glasses.
After they become proficient, they can continue the journey to building the next best home brew.