You can only use one of the three following connections:1. Barrel Jack (for 7-12V power supplies)2. Vin (for 7-12V power supplies)3. 5V (for 5V power supply)PICK ONE and ONLY ONE.
I really wish you would not confuse the poor fellow with such unhelpful nonsense!
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.
Besides the lack of a caveat to indicate the 5V available is not able to power anything of consequence.
Yes, you finally "got it". That was exactly my complaint. The fellow appears to be having trouble comprehending that single detail. Under the circumstances, and in particular that he is wishing to power something "of consequence", I feel that we need to be consistent in advice and not favour recidivism in any form.
Totally forget the "barrel jack" and "Vin" - never even mention them as possible options.Even if you feel that they might be usable when someone has a UNO (or my preference: Nano) and nothing else beyond a few indicator LEDs and resistors, I think the requirement for a 5 V power supply - and I cannot say this too often; "phone chargers" are by far the most readily available option - should be emphasised as the preliminary basis of any further progress.
We are talking apples and oranges. I am talking power in. You are talking power out. Your complaint has nothing to do with what I am saying. I am saying to choose one of the three power inputs and you are "confusing" issues by including power output (ie., using power from the 5V pin). I never said to use the 5V power out....The 5V pin as a power source (out) is useless. On that we agree.
How many devices out there run on 9V?
Your stance is very peculiar, since you appear to keep criticizing the use of two separate power supplies, but powering the Arduino via the regulator at 9 V mandates a second supply for the 5 V yet you are suggesting that it is "possible" to use a 9 V input.