Basically we have an Ultrasonic sensor that measures the distance and the LED’s bar graph will light up according to our distance from the sensor and as we get closer the buzzer beeps in a different way. This circuit can work as a parking sensor! It's easy and cheap.
1x 74HC595 8 Bit Shift Register
8x LED’s (for example: 3x red, 3x yellow, 2x green)
9x 220 Ohm Resisters
1x Ultrasonic Sensor (for exemple: HC-SR04)