# Seismograph Lesson Build a seismograph with household materials ## Topic Acceleration & Analog Read Pin ## Quick Links * [activity](/lessons/seismograph/activity) * [challenge](/lessons/seismograph/challenge) ## Prior learning/place of lesson in scheme of work Learn how to **show LEDs** to turn on a LED light pattern on the LED screen. We will be learning basic comments such as show LEDs and pause. ## Documentation ```cards basic.forever(() => {}); radio.sendNumber(0); input.acceleration(Dimension.Strength) radio.onReceivedNumber(function (receivedNumber) {}); led.plotBarGraph(0, 0); ``` ## Objectives * learn how to repeat code forever in the background * learn how to display a vertical bar graph based on the value. * learn how to return the sum of the two numbers * learn how to get acceleration value in milli-gravitys * learn how to read the connector value as analog as a value comprised between 0 and 1023 ```package radio ```