Literally coin-op hardware? Communication between Unity and hardware.

Basically I am developing a game of type which are present in malls which require coins to continue. So, is there any plugin or unity has this feature inbuilt?

I’d do it via an Arduino.

It’s actually a lot simpler than you’d think. You can just use Unity’s built-in input system. No need for an Arduino, no need for plugins or extensions of any kind.

Create a new input, call it something like “Coin”. Then using a keyboard encoder (like the x-arcade or iPac), wire up the keyboard inputs to authentic arcade joysticks, buttons, and coin mechanisms.

When you put a coin into the mech, it’ll send a signal to Unity just like a button being pressed. Just work it into your games controls.