This project consisted in the making of a functional replica of the speedometer seen in the cult science-fiction film Back to the Future.
The finished product relies on a Freematics OBD-II UART adapter, connected directly to the car's ECU via the standard OBD-II port.
The circuit is controlled by an Arduino Nano board, wired to a switch (for mph/OFF/kmh functionality), the adapter, and two 7-segment displays.