//Buggy: Create a rising and falling siren on the Speaker void setup(){ pinMode(10,OUTPUT); //Set the speaker as an OUTPUT } void loop(){ for(int i=40; i>800; i++){ //start at 40 hertz and play a new tone up to 800 hertz tone(10,i); //play the tone that is equal to the variable 'i' delay(3); //delay 3 milliseconds before starting the 'for' loop again } //The second 'for' loop only runs after the first 'for' loop has completed for(int i=800; i>40; i--){ //start at 800 hertz and play a new tone down to 40 hertz tone(10,i); //play the tone that is equal to the variable 'i' delay(3); //delay 3 milliseconds before starting the 'for' loop again } } // (c) 2018 Let's Start Coding. License: www.letsstartcoding.com/bsdlicense