This is tutorial number 1 from our series of Arduino tutorials and in this part I will talk about blinking an LED using the one already available on the Arduino Uno board or using an external LED to ...

Back to the Blink example In the Blink sample's setup () function, there is one line of code: pinMode(LED_BUILTIN, OUTPUT); Both LED_BUILTIN and OUTPUT are #defines defined by Arduino headers.

Setup 1. Run Arduino. 2. Open the LED blink example sketch: File > Examples > 1.Basics > Blink. You should see a window like in Figure 2. 3. Choose Tools > Board, then select your board, like in ...

For the first sketch, let's blink an LED and then extend it to blink multiple LEDs alternately. Before the software part, let's first set up the circuit to connect the LED to the Arduino.

The power LED is on because, well, the Arduino has power! Why is the other LED blinking? Because the Arduino is executing the pre-installed software called Blink.