It seems everything electronic these days takes 5v power, including many of the gadgets I make. So how do you power these? Well, it just so happens that cellphones, ipads, smartphones and about any rechargeable portable thing has standardized on a USB cable for charging, and you can find these chargers all over the place. This one was $7 at Wal*Mart.
This one didn't come with a USB cable, but it didn't take much digging to find an old phone charge cord from a phone I don't use any more. It had a USB plug on one end and something odd on the other.
Phone Cord Gets Whacked
So all I did was whack off the oddball end of the wire. Inside a USB cable, you'll find 5 wires. Usually Red, Black, Green, White and uninsulated. Predictably, red was + and black was -. Sometimes when the cable comes with the charger it might be missing the green and white wires.
If the colors in your cable don't make any sense, it won't take a couple minutes with your volt meter to figure it out.
Your meter only says 4.8v? Don't worry, that's well within spec. This charger says 5.03v.
What's it good for?
This one says it's good for 1 amp.
That will run a LOT of microcontrolers, LED's, Servos and such.
This is an INDOOR device. If you use it to power things in your garden, be sure to protect it from getting wet.