Good day, I am new to Arduino and am having trouble getting the first project (LED light) in the starter kit to work. I have the set up correct with the 220 Ohm resistor, but the LED bulb never comes on when using the 5V and GND from the Arduino. I tested the same circuit on the same breadboard with a 9V battery and everything worked perfectly.
The Arduino is getting power from the computer via USB, and the On light (green) and L light (yellow) are working on the Arduino.
Is there a way to troubleshoot, or reset, the 5V power on the Arduino? I am using Uno R3. Thank you.
The Uno has an onboard LED. Can you flash that, using the example Blink that comes with the IDE?
Next question will be, LEDs are polarity sensitive - did you try the LED with the leads in both directions? If not, turn it around, try it, and report back.
I figured out the issue! The culprit is the red and/or black power wires that came in the kit. Something is not connected in them, between the wire and the lead. When I tested the circuit with different wires, using both the 9V and the Arduino, everything works fine. Thanks @camsysca for nudging me in different directions!
interal +5v is present on that pin, but it isn't designed as a power supply. You get current dependent random resets, etc. Even the 20mA for an LED can cause issues, especially if you're near the total 200mA limit with a 12V ps voltage.
+5V is a supply input to power the card directly. The fact you can steal a few mA doesn’t make it best practice. If you want to power your project, use a USB charger or a real power supply for long term operation. The +5V should be considered a test point when not used as an input.
Context is everything, @madmark2150 , as you should know. This thread is about a newbie powering a single LED, using 5V from his USB, then 9V from a battery. Neither option poses any problem for a single LED.
OT rants about abuse of the 5V output are just that, OT rants.
It is a TECHNICAL stament that the +5V pin is an input, not an output. How many threads are here with a user complaining that their attempts to power the world fail even tho they can light an LED?
The thread title shows the fallacy because it complains that the "5v power out" isn't working. My response is "because it's an INPUT!".
It's neither, or both.
The 5volt pin is connected to the 5volt power rail.
You can supply and draw current to/from it if... you know the limitations.
Leo..