This is yet another ultrasonic range finder project using Arduino. We have done several similar projects in the past.
It allows us to control a buzzer based on the distance detected by an HC-SR04 sensor, making it sound with a frequency proportional to the distance from an obstacle.
NE555 and Arduino for interactive sound production
MicroSD card breakout board for Arduino
Arduino Project 58- Infrared controlled robot car
DC Boarduino- A DIY Arduino
An experiment with LDR and Arduino
How to use infrared module with Arduino
FTDI basic breakout board
3 useful applications for serial data transfer between Android and Arduino
Assembly Tutorial of Amarino Nano 1.0
Arduino Project 30- Seven Segment Display Countdown with Buzzer and LED
Amarino shield- CD4094 control with Arduino- WITHOUT SMART PHONE
Make Arduino on breadboard using FTDI breakout board