Arduino Auto Knock
This is not a cheap version of the $20 commercial motion sensor chime, nor a fancy one. I built this because I have the parts on hand, I enjoy building it, and I learn how to control ultrasonic sensor, relay module and solenoid with Arduino.My office is free to enter for almost any workers, because ...By: chienline
Continue Reading »
from Instructables: exploring - featured http://ift.tt/2loRs4E
via IFTTT