flashing " L " and " TX " on Arduino R3 when pluged in

Development Tools IDE 1.x
3

chickenhawk:
Our first sketch was to be " blinking an led " Will the leds stop blinking when we load our first sketch?

It depends on the sketch. If the sketch is setting pin 13 HIGH and LOW then the "L" LED will blink. If the sketch is printing to Serial then the "TX" LED will blink. If you do this:

  1. Select your Arduino board type from the Arduino IDE's Tools > Board menu.
  2. Select the COM port of your Arduino board from the Arduino IDE's Tools > Port menu.
  3. Select File > New from the Arduino IDE menus.
  4. Select Sketch > Upload from the Arduino IDE menus.

Then once the upload finishes there should be no blinking LEDs.