I have a keypad that, if you enter the correct code, it opens a solenoid for 5 seconds. This unlocks my shotgun or it will once I get the project done completely. Here is the shotgun lock, if you are interested. http://www.policeproducts.com/santa-cruz-gun-lock-for-pump-shotguns-p-1038.html
I have a 9v wall wart powering the Arduino, but two 9 volt batteries powering the Solenoid. Like so: http://www.instructables.com/id/Controlling-solenoids-with-arduino/
Can I lose the two 9 volt batteries and have one wall wart (110v to whatever DC) that powers both the Arduino and the solenoid?
I have just enough electrical knowledge to make my head hurt, so go easy on me. This is my first project. I am much better with the coding than the electrical.
In case anyone asks, it is for easy access in case of zombie attacks. Of course.