These pages are intended to assist new and old Arduino users with various issues of the hardware side of things, how to hook your modules together, etc. WE DO NOT HELP WITH CODE, Please try our Arduino Forum (growing) of another forum. Also, DO NOT ASK US TO DESIGN YOUR PROJECT! That can be done, on a contractual basis, but it is not the intent of this page to do your work for you for free. All requests of such will be ignored. You have been warned. Class/Student projects WILL NOT BE ASSISTED other than what is on these pages.
Finding Answers to YOUR problem
Believe it or not, over the past 7 years of Arduino, there has been a vast collection of information generated. You are probably NOT the first to have the problem you are encountering. How would you find if someone else has had the same issue? use a web search. It is that simple many times. Say you were having issues with your Arduino not driving a servo properly, what would you do? I’d google “Arduino, servo, jittery” for example, out of the thousands of records with those terms I am sure I could locate something that would help. If I had exhausted several dozen attempts, and still have issues, THEN I’d post to a forum with what I had found, what I had tried, where I am still having problems. I’d include my code and wiring diagram if possible.
Multiple Power Sources
Can you power your whizzbang module that needs 12V from the 5V of the Arduino? Nope, your whizzbang module needs 12 volts to operate properly. if you try it on 5v, it may work, but more than likely if it did anything it wouldn’t be what it was designed to do.
Can I power my Arduino from 6-12 volts? Sure, this will work fine, but ONLY if you use the coaxial power jack OR the VIN pin. DO NOT FEED HIGH VOLTAGE ANYWHERE ELSE ON THE ARDUINO BOARD.
Can I power my Arduino from 5 volts? Absolutely, feed it 5 volts on either the USB jack or +5 volt pin. Do not use the VIN or power jack, as 5V is not enough to operate the regulator to provide 5V out of it.
I hooked a voltage higher than 5V to the 5V pin, and my Arduino doesn’t seem to respond or function anymore. Congratulations, you have killed your Arduino. Unless you can determine which parts you blew up and replace them, it ain’t going to work correctly.
Ok, I’ve got my whizzbang module on 12 volts, my Arduino on a USB 5-volt adaptor, I’ve wired the signal from my whizzbang module to my Arduino, but I don’t see a signal, why? Well, unless you have the ground of the whizzbang module AND the ground of the Arduino connected together, the signal from the whizzbang module has no reference. 99.99% of signals, positive or negative, are referenced to ground. Think of this as trying to hook up only the positive pole of a battery.. does it supply power? no, Why? You do not have a circuit to complete the path for voltage and current to flow.
Basic LED stuff
Basic pushbutton switch connections
The Relay Project