It was sometime last year, that I asked about what power supply I could use for 12v led strip and arduino, and was told anything between 7v and 9v to the arduino.
As I said earlier in this thread, the voltage to the board and devices is 4.92v. As BJHenry said that something is dragging down the voltage, which I suspected when just using a 5v powersupply, which wouldn't power the display and show anything.
I did try to power this project with 9v to the breadboard, but the display screen came on then went off again.
How should I power the whole project, so that everything works
From this link:
I read this: from the Arduino website:
5V. This pin outputs a regulated 5V from the regulator on the board. The board can be supplied with power either from the DC power jack (7 - 12V), the USB connector (5V), or the VIN pin of the board (7-12V). Supplying voltage via the 5V or 3.3V pins bypasses the regulator, and can damage your board. We don't advise it.
Then someone posted this:
Yet, provided that you do not exceed 5.5 volts on the +5v pin, you can absolutely use it to supply the arduino. You bear the responsibility of ensuring that you do not exceed 6v though. – David Hoelzer