Sensor de Proximidad

http://bkargado.blogspot.com/2013/09/todosobrehc-sr04.html https://www.youtube.com/watch?v=zITpQQLj-AA http://www.micropik.com/PDF/HCSR04.pdf http://elprofegarcia.com/?p=198 http://tecbolivia.com/index.php/articulos-y-tutoriales-microcontroladores/17-com o-medir-distancias-con-el-sensor-ultrasonico-ping https://www.youtube.com/watch?v=aSEkdWSp05Y http://avrprogramer.blogspot.com/2014/01/obstacle-detection-using-ultrasonic.htm l http://www.wzona.info/2012/09/echolokacija-naudojant-hc-sr04.html https://www.youtube.com/watch?v=j9iwe6LdD0I http://extremeelectronics.co.in/avr-tutorials/ultrasonic-rangefinder-hc-sr04-int erfacing-with-atmega8/ http://www.instructables.com/id/Ejemplo-b%C3%A1sico-con-HC-SR04/step4/C%C3%B3dig o/