# flashing heart blocks lesson Learn how to create LED images with a global variable. ## Topic Pause ## Quick links * [activity](/lessons/flashing-heart/activity) * [quiz](/lessons/flashing-heart/quiz) * [quiz answers](/lessons/flashing-heart/quiz-answers) * [challenges](/lessons/flashing-heart/challenges) ## Prior learning/place of lesson in scheme of work Learn how to `show LEDs` by showing an image on the LED screen. We will be learning how to create a blinking app using a forever loop as well as simple commands, such as show LEDs, pause, and clear screen. ## Documentation ```cards basic.forever(() => {}) basic.showLeds(` . . . . . . . . . . . . # . . . . . . . . . . . . `) basic.pause(100) basic.clearScreen() ``` ## Objectives * learn how to repeat code in the background forever * learn how to show LEDs on the LED screen * learn how to pause your code for the specified number of milliseconds * learn how to turn off all the LED lights on the LED screen