I am a newbie to arduino (to electronics actually) and have been working through the adafruit tutorials. I am currently in Lesson 5 (http://www.ladyada.net/learn/arduino/lesson5.html) and am having trouble understanding this statement :
Can someone please help with this?Whats this 100Ω resistor all about?
There's a 100Ω resistor we use to connect the input pin to either HIGH or LOW voltage. Why is it there? Well, lets say you accidentally set P2 to be an OUTPUT type pin, but then you connected it to 5V. If you write a LOW to the pin (0V) but its connected to HIGH (5V), you've basically caused a short circuit at that pin. This isn't very good for the pin and could damage it! The 100Ω resistor acts as a buffer, to protect the pin from short circuits.
Thanks a lot!,
yogesh