CAN-bus (controller area network) is a standard designed to allow microcontrollers and other devices to communicate with each other within a vehicle without a host computer. It was designed specifically for automotive applications but can also be used in many other applications (industrial, entertainment). Today’s modern automobile can have as many as seventy electronic control units (ECU) for various subsystems. These include the engine control unit which is typically the biggest processor. Others are used for transmission, airbags, antilock braking, cruise control, electric power steering, audio systems, lighting, power windows, doors, mirror adjustment, battery and recharging systems for hybrid/electric cars.