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I am an electronics engineer by trade and I have been feeling some stress about how I spent too much free time
developing my programming skills over my circuit skills.

Then, the idea hit me. I can practice developing circuit systems by making a video game just from circuit logic.
I am specifically going to limit myself to analog circuits because I am more interested in analog circuit logic than digital circuit logic
or mixed-signal circuits.

It has been done by Tennis for Two in the 1950s using an analog computer and an oscilloscope.


However, the graphical display was an oscilloscope which limited it to only having 1 point per y-coordinate on a 1 channel oscilloscope.
A switching circuit had to be used to switch between display for tennis ball and net.

My game will try to use a circuit block to convert voltage signal information to a video signal for a composite or component cable
that will be connected to a television set.

I'm excited about this project! If this is successful, maybe this might be a different direction for the video game meta to take.

Man, I have only the most rudimentary understanding of what you're trying to do!

But, it sounds really cool.

How can you use circuit logic? Like... are you going to build a board with a tiny microprocessor on it? And how in the world do you translate that to a video signal?

Thanks, man! = )

Deckhead wrote: ↑Fri Jul 24, 2020 10:03 am
How can you use circuit logic? Like... are you going to build a board with a tiny microprocessor on it?

I am not going to use a microprocessor since it is a digital circuit component and I want to only use analog circuit components for analog circuit logic
for this project.

I can use analog circuit logic by manipulating a voltage representing the x coordinate of a player and another voltage representing the y coordinate of a player.

Op-amps allow me to do addition, subtraction, and comparison with voltages which is enough for collision detection and moving a player.

https://www.electronics-tutorials.ws/category/opamp

Deckhead wrote: ↑Fri Jul 24, 2020 10:03 am
And how in the world do you translate that to a video signal?

I still need to figure out how to convert a 2d image of the world into a video signal to pass to a tv set.

Fortunately, I have these resources that explain how analog video signals make an image on screen.
https://www.maximintegrated.com/en/desi ... /1184.html
https://www.maximintegrated.com/en/desi ... 7/734.html

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The game I am going to develop will be a simple game in which players try to stab the back of the other player to win.
The player who gets their back stabbed dies. Last player standing is the winner.

It is a simple game that will only require collision detection and moving a few dots across the screen.

Oh I see what you mean by "analog" now; this sounds really cool.

I started tracking this project on Github.

https://github.com/adct-the-experimente ... VG-Stabber

So far I was able to have player position and weapon position set by joystick input and center weapon around player.

I need to design a circuit that reacts to zero volt difference between a player's position and the other player's weapon
for collision detection.

I have collision detection working well.

It was difficult, but rewarding.

I just made a circuit that subtracted voltages representing x,y coordinates of 2 objects.
Then, the subtraction result was passed to a positive negative indicator circuit with its output connected to a differentiator to get the moment
that a zero was crossed i.e. polarity of signal was changed.

sign = 5V if (position_obj_1 - position_obj_2) is positive, -5V if (position_obj_1 - position_obj_2) is negative
collision ~= d/dt * sign

I still am completely unaware of what you're saying, but I'm amazed that you're doing it just the same.

Do you have photos? I'm curious how this looks.

I'm using LTSpice circuit simulation software at the moment. I will move on to real parts soon.

This is a picture of the whole circuit. It uses 24 op-amps, 4 nmos, many resistors.


This is the test circuit for collision detection.
The picture shows that whenever a player's x coordinate and a opponent's weapon x coordinate
are the same, the difference between them is zero, then zero detect signal changes sign, and the change in sign is indicated by the
derivative of the zero detect signal.

I have been having a very difficult time trying to make a way to produce discrete graphics(e.g a dot) in video signal from
from only continuous analog signals.

Analog signals are continuous and can't be discretely changed at a certain point, but rather over a certain range periodically with the change going on forever.
It is nearly impossible to make discrete graphics from direct analog signals without converting output into digital data or
inventing some crazy math. Video games use digital signals to produce a digital TV video signal or use digital signal converted into analog TV video signal.

This is why I am taking the video game into a new direction.
I won't make discrete graphics, but instead I'll make continuous graphics that are directly affected by output signals representing
a video game parameter. I need to change the logic of my game and base it on the production of the TV video signal itself.

I have a new idea for the game.

The game will be based on generation of a real-time analog video signal.
It is a simple fighting game in which a colored line drawn on screen represents the actions of the defending player and the other player
must accurately copy the defending player's actions to win. The line will stay on the TV until it is redrawn.

The more the attacking player accurately copies the defending player's actions, the more health the defending player loses.

The defending player or the attacking player can switch roles with a button press.

Also both players are able to start a new line on the TV with a button press.

If this doesn't work, I am probably going to make a software video game out of it since it seems like an interesting fighting video game.

I'm excited for it. The details will need to be worked out, but it will be really interesting to see the history of your opponent's actions
on TV. The game mechanics will also make for some fast-paced gameplay strategies.