Virtual Input Axis

Don’t know if anyone knows how to implement input axis in this application:

• My application received USB signals from arduino then decode it as a car tray to turn car left / right.
• There are two hardware buttons attached in arduino, Left & Right
• Unity reads USB signal at “update()” loop periodically
• When left button pressed, the “left” bool goes high. While when left button released, the corresponding bool goes low
• My left / right signals are not from neither keyboard NOR joystick. So unity inputManager cannot be used.