For the target sensor i will use a piezo buzzer. They will react on vibration, when the bullet hits the target, an vibration will start and the piezo will notice this.
An voltage will send to the Arduino to inform that a target has been hit. The electric sheet is for one target only. I will use 3,5 mm phone to connect the targets with a cable.
Remember this is only for the wired version of the shooting game.
It’s not recommend to directly connect the piezo to the Arduino because it can be some high voltage. Thats why we need to add some diods and resistors to the sensor before it will go in to the Arduino.
There is also an blue led that will turn on when the target is going to hit.