The following diagram shows the locations of the LEDs that will be used in this chapter:

The pin 13 LED is a simple single red LED that will be used in the first recipe. There are a total of 10 NeoPixels on the board. Each NeoPixel is made up of a red, green, and blue LED. By controlling the individual brightness of each of these LEDs, you will be able to set any NeoPixel to a specific color.

In this recipe, we will learn how to turn the pin 13 LED on and off. This is the simplest LED available on the board as it has only one color, and interacting with it in Python is also very straightforward. For these reasons, the pin 13 LED is a good starting point.

You will need access to the REPL on the Circuit Playground Express to run the code presented in this recipe.

To do this, perform the following steps:

1. Run the following lines of code in the REPL:

>>> from adafruit_circuitplayground.express import...

Controlling the brightness of the pixels will be the theme of this recipe. It is important to be able to set the brightness of the pixels depending on the need of the project. Note that you will have to change the brightness to a level that is bright enough so that the pixels are clearly visible, but not so bright that it causes discomfort.

You will need access to the REPL on the Circuit Playground Express to run the code presented in this recipe.

To do this, perform the following steps:

1. Run the following...

This recipe will show you how to set the a specific NeoPixel to different colors. It will then show you how to change the color of any of the 10 NeoPixels that come with the board. This will be a useful recipe to follow so that you can start unleashing the power and flexibility of these onboard pixels.

You will need access to the REPL on the Circuit Playground Express to run the code presented in this recipe.

To do this, perform the following steps:

1. Run the following lines of code in the REPL:

...

There is a common convention to express any color using the hex code, which works by representing the red, green, and blue components of the color. This recipe demonstrates how to set the color of a NeoPixel using this hex code convention. Using such a popular convention will be useful when you want to apply specific color settings from other applications on the web or your desktop.

You will need access to the REPL on the Circuit Playground Express to run the code presented in this recipe.

Using human-readable color names can make it much easier to keep track of what colors are in use in your application. This recipe demonstrates a technique that allows you to set pixel colors using regular color names. This feature of referring to colors by a standard set of color names is available in popular languages, including CSS. This recipe shows you how to bring this feature to your MicroPython scripts.

You will need access to the REPL on the Circuit Playground Express to run the code presented in this recipe.

This recipe explains how you can set all the pixels to one color through a single call, instead of looping through all the NeoPixels and setting their colors individually. You can use this technique to create a nice effect to set all 10 NeoPixels to the same color. They are arranged in a perfect circle, so it creates a ring of color when they are all set to the same color. It is also an easy way to turn all the NeoPixels off in one call.

You will need access to the REPL on the Circuit Playground Express to run the code presented in this recipe.

This recipe will explore how the slicing feature can be used to set a specific range of pixels to a specific color. This can be quite useful when you want to turn the ring of pixels into a gauge to show the level of a value from 1 to 10. Essentially, it provides a clearer and simpler way of setting a range of pixels to a particular color.

You will need access to the REPL on the Circuit Playground Express to run the code presented in this recipe.

To do this, perform the following steps:

1. Run the following...

This recipe demonstrates a technique that can be used to endlessly generate random colors. We will then use these random colors on a specific NeoPixel. Adding randomness to the color section can make projects more interesting, as you can never predict the exact sequence of colors that will appear as your script executes.

You will need access to the REPL on the Circuit Playground Express to run the code presented in this recipe.

To do this, perform the following steps:

1. Run the following lines of code in...

This recipe will combine some aspects of the previous recipes in this chapter to create an animation using randomly selected colors. This recipe builds on the techniques of other recipes to create your first animation. With 10 pixels on the board, there are a lot of options for creating engaging visual animations on the board—this is just one of those.

You will need access to the REPL on the Circuit Playground Express to run the code presented in this recipe.

To do this, perform the following...

This recipe will produce a ring of colors following the same sequence of colors found in a rainbow. These colors will each appear after a certain delay, creating a rainbow animation effect. Using a sequence of colors that naturally fits together, like the ones found in the rainbow, can be both pleasing and engaging. The strength of this animation is in learning how to control the exact sequence of colors being animated, whether they be in a rainbow sequence or another sequence of your choosing.

You will need access to the REPL on the Circuit Playground Express to run the code presented in this recipe.