![header-lesson-03](assets/header-lesson-03.png)

# Blinking an LED

Now that you know about breadboards and resistors and have built a basic circuit with an LED and the micro:bit, it is time to make the LED blink.

![kitronik-blink-one-led-04](assets/kitronik-blink-one-led-04.png)

Open [MakeCode](https://makecode.microbit.org/) and create a new project.

![makecode-blink-one-led-00](assets/makecode-blink-one-led-00.png)

Select the Advanced drawer in the Toolbox.

![makecode-blink-one-led-01](assets/makecode-blink-one-led-01.png)

Select the `digital write` block.

![makecode-blink-one-led-03](assets/makecode-blink-one-led-03.png)

Insert the `digital write` block into the forever block. You can change the value by typing a value or using the slider. A value of `0` means the digital signal will be off, and a value of `1` means the digital signal will be on. This is what will make the LED blink. The pin is set to `P0` and does not need to be changed, because the LED is connected to `0` on the  Kitronik prototyping plate.

![makecode-blink-one-led-04](assets/makecode-blink-one-led-04.png)

Change the value to `1` to turn the LED on.

![makecode-blink-one-led-05](assets/makecode-blink-one-led-05.png)

Next, select the Basic drawer in the Toolbox.

![makecode-blink-one-led-05](assets/makecode-blink-one-led-06.png)

Select the `pause` block.


![makecode-blink-one-led-07](assets/makecode-blink-one-led-07.png)

Place the `pause` block in the `forever` block below the `digital write` block.

![makecode-blink-one-led-08](assets/makecode-blink-one-led-08.png)

Duplicate the `digital write` block.

![makecode-blink-one-led-09](assets/makecode-blink-one-led-09.png)

The duplicated block appaears over the original blocks. .Select the duplicated `digital write` block.

![makecode-blink-one-led-10](assets/makecode-blink-one-led-10.png)

Place it below the `pause` block in the forever block.

![makecode-blink-one-led-11](assets/makecode-blink-one-led-11.png)

Change the value from `1` to `0`.

![makecode-blink-one-led-12](assets/makecode-blink-one-led-12.png)

Duplicate the `pause` block.

![makecode-blink-one-led-13](assets/makecode-blink-one-led-13.png)

Select the duplicated `pause` block.

![makecode-blink-one-led-14](assets/makecode-blink-one-led-14.png)

Place the duplicated `pause` block below the second `digital write` block.

![makecode-blink-one-led-15](assets/makecode-blink-one-led-15.png)

Notice that the default value is 100. MakeCode measures time in **milliseconds** (ms), and 1000 ms is equal to one second. The default value of 100 is 0.10 (one-tenth) of a second, which will cause the LED to blink 5 times (on and off) in a second. Let's change this value to change the blinking rate.

![makecode-blink-one-led-16](assets/makecode-blink-one-led-16.png)

To make the LED blink once (on and off) in a second, change the value from `100` to `500`.

![makecode-blink-one-led-17](assets/makecode-blink-one-led-17.png)

Change the value in the other `pause` block from `100` to `500`.

![makecode-blink-one-led-18](assets/makecode-blink-one-led-18.png)

Now both values are `500` code will turn the LED on for half a second and turn the LED off for half a second.

![makecode-blink-one-led-19](assets/makecode-blink-one-led-19.png)

The program is now complete. The LED should be turning on and off every second.

Try experimenting with different blink rates by changing the value in the `delay` block.

The micro:bit is now ready to be flashed with code. Press the download button to transfer the code to the micro:bit.