Circuit/System Description

The object alarm module directly controls the rear parking assist (RPA) display. The RPA display consists of 2 amber and one red LED that indicate the distance of an object from the rear bumper. The object alarm module will also use an audible warning by sending a serial data message to the radio. Each object sensor is a 3-wire sensor that is both a transmitter and a receiver that includes a signal circuit, a low reference circuit, and an 8-volt supply voltage circuit. The object alarm module supplies 8 volts to the object sensors via the object sensor supply voltage circuit and provides ground via the low reference circuit. The object alarm module triggers the sensors in a sequential loop and after each sensor transmits, the object alarm module uses the echo or signal return to calculate the distance and position of an object from the rear bumper.