hello all you wonderfully intutive minds. i am trying to figure out what kind of transistors i need to use for my project. i will be using a uno to control a TFT screen that will be relaying commands to a mega via serial communication to operate all the cool stuff i have added into my car. but the most important thing i want to do is do a pin number lock screen that gives way to a touch screen start ]:) ]:D so im figuring transistors or relays but the arduino can not push a automotive 12v relay so how do i get this to work?
and i am hell bent on this idea so please dont post the "why dont you just do a push button" cause this is purely for the thrill of making it. with that being said who knows what im looking for?