This video explains why we need to use resistor with push button with arduino?
Download the code for this video: http://bit.ly/pushbutton-resistor
View INPUT_PULLUP in my other video with push button (Dec 2017) : https://youtu.be/7CCSRs5bvH0?t=8m00s
Tutorial by Robojax.com
Get other projects code and learn Arduino
http://robojax.com/learn/arduino
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