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arrow_back Flashing Letters


In this add-on, you will program letters to flash across the screen and spell out your cause.

To start, click "Choose sprite from library," then click "Letters" on the left-hand side of the popup menu.

There are a few different styles of letters.

Choose a style you like, and find the first letter of the name of your cause.

Click “OK.”

To add the rest of the letters of your cause, select the costumes tab, click "choose costume from library," and add the next letter.

Repeat this process until the entire word is spelled out.

Add the letters to a single sprite.

Each letter will be its own costume within a sprite.

Take a look at the example project.

When the play button is pressed, the letters flash across a multicolored backdrop.

Then, the letters disappear and the backdrop switches.

At the same time, the rest of the sprites appear on the screen.

To make the letters flash across the screen when the play button is pressed, select the letter sprite, and add a "when I receive play" block.

Add a “next costume” block to make the letter on screen change.

To spell out the entire word, add a repeat loop.

Make the number in the repeat loop one less than the number of letters in the word.

Sports is six letters.

The animation will start with the first letter S, then change costume 5 times to show the 5 following letters and spell out the entire word.

Try it out.


The letters are changing too fast to read the word.

To fix that, add a “wait” block after the "next costume" block.

Adjust the time in the wait block until the name looks readable.

To make the letter sprite start on the first letter of the word when the play button is pressed, add a "set costume" block above the “repeat” block.

Select the first letter of the word in the dropdown menu.

Add a “wait” block under this block, too.

To make the letter sprite disappear after it spells out the name of your cause, add a "hide" block at the bottom of the code stack.

Make the letter sprite reappear when the play button is clicked by adding a "show" block under the "when I receive play" block.

Run your code again.

This looks pretty good, but the letters look a little small.

Add a "set size" block under the "when I receive" block, and set the size to something greater than 100%.

This example uses 200%.

Run your code.

This is a pretty cool effect.

You can stop here, and move on to your next add-on.

Or, if you'd like, make the backdrop change and the other sprites disappear when the letters flash on the screen.

Then, program the sprites to reappear after the word is spelled out.

To do this, select the stage, and add a "when I receive" block.

Select the “play” message from the dropdown menu.

Under this, add a "switch backdrop" block, and select "beachball" from the dropdown menu.

To make the other sprites hide when the animation starts, add a "hide" block under the "when I receive play" block for each sprite.

Make the sprites reappear after the letters flash on the screen by selecting the letter sprite and adding a “broadcast” block to the bottom of the code stack.

Click the dropdown menu, select new message, and call the message something like, "Show sprites."

For each sprite, add a "when I receive" block, and select "Show sprites" from the dropdown menu.

Under this, add a "show" block.

Select the spokesperson sprite.

This sprite delivers the opening message when it receives the play message.

To make the sprite wait to say the message until after the letters have flashed on the screen, click and drag the “say” blocks from the "when I receive Play" block to the "when I receive show sprites" block, and place them under the "show" block.

Finally, to change the backdrop back to the one you selected after the letters stop changing, click the stage, and add a "when I receive" block.

Select the message you just created, and add a "switch backdrop" block.

Select your original backdrop from the dropdown menu.

Click the play button to try out your code.


What a great way to start your viral video!

This add-on has a lot of code.

If you get stuck or have any questions, ask your neighbor or put up your sticky note to get the attention of your CS First Guru.

Now it's your turn!

Program the letter sprite to flash across the screen.

Then, hide the other sprites when the letter sprite is shown.

Finally, show the other sprites after the letter sprite has finished spelling out the name of your cause.

Choose an Add-On
Scene Change
Customize your video with different backdrops.
Flashing Letters
Create an exciting video opening.
Add other characters to support your cause.
Inspire with Music
Add uplifting music that will start when the play button is pressed.
Target Your Message
Change your message based on the user's response to a question.
Celebrate your Cause
Get the sprites moving!
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  1. Choose an Add-On, and click "watch" to learn how to build it.
  2. Once you finish one Add-On, try another one below the video!