Boards LED on pin 13 Flashes continously

Using Arduino IDE 1.x
1

When I plug my Arduino Uno into the usb port on my computer, the built in LED on the board flashes. This is before I start my Arduino software. It will continue after I press the reset button.

When I run the very basic blink sketch, there are two other built in LEDs on the Uno that also flash, but then go out.

I am running the Arduino software on a computer running Window XP Service pack 3.

Any suggestions?

2

Sounds like normal operation to me? The bootloader on the controller chip uses/manages pin13 led until it passes control over to a uploaded sketch, then the sketch controls what you do with pin13 led.

Lefty

3

Thanks Lefty. I had a lot of problems just getting the computer I am using to load the software. When I first got my Uno, I had a dedicated laptop for it. I was scanning for viruses, malware, etc one day when the mother board burnt out. The Uno software and hardware worked great on it. Right now I have my Uno plugged into my new laptop running windows 8, and the led on pin 13 is flashing. Thank you for clarifying this

4

gusofmerced:
This is before I start my Arduino software.

The Arduino board will run whatever program it has regardless of what you are doing on your PC.

gusofmerced:
It will continue after I press the reset button.

That starts the previously loaded program over, not erases the memory.

gusofmerced:
there are two other built in LEDs on the Uno that also flash, but then go out.

I'm going to guess they say "TX" and "RX" next to them... probably a hint to why they flash.

5

James C.
Yes you were right about the tx and rx leds. Any idea about what would happen if I burned my bootloader? I saw that when I was on my tools menu.

6

gusofmerced:
Any idea about what would happen if I burned my bootloader?

If you have a hardware programmer attached (which is listed in the Programmer part of the menu), then the bootloader will be re-programmed. Otherwise, nothing will happen.

7

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8

Thanks spycatcher2k. I modified a the blink program to set pin 13 low and go into a loop. now it stays out. I will do what you do. Thanks for the tip