ProximityArduino This is a project to create an Arduino with proximity sensing and LED output
Proximity Detector with Lights (created 16 Oct 2015 by Faran17)
Misc links to ideas and code sources:
https://www.arduino.cc/en/Tutorial/SFRRangerReader
https://www.arduino.cc/en/Reference/DigitalWrite
Parts at http://www.amazon.com/Arrela%C2%AE-Hc-sr04-Ultrasonic-Distance-Measuring/dp/B00NG8TJ6E/ref=sr_1_1/190-2812982-0623320?ie=UTF8&qid=1445035828&sr=8-1&keywords=srf04