Start Arduino course 06 - Buzzer

Transcription

1 Introduction: For your final project, we will be combining the different circuits and code elements we ve created to create a musical instrument. It can use any of our sensors and inputs to control our Piezo Buzzer. It s up to you. Goals Create a buzzer circuit. The Buzzer Our Piezo buzzer is used to create tones and notes using PWM and a built in Arduino library. Page 1 - Start Arduino Course: 06 Buzzer

2 Circuit Buzzer Hardware This is a simple circuit to get our piezo buzzer working. Make sure the + of the buzzer is connected to pin 11 and the of the buzzer is connected to Ground. For this, we will need: 1x Arduino Uno 1x USB Cable 1x Piezo Buzzer 1x 220 Ohm Resistor (Red Red Brown Gold) 2x Jumper Wire Page 2 - Start Arduino Course: 06 Buzzer

3 Circuit Buzzer Code Make a new sketch in the Arduino IDE and name this Buzzer. //array of musical notes int notes[] = { 220, 440, 660, 880, 1100, 1320, 1540; //variable to store buzzer pin int buzzerpin = 11; void setup(){ //set buzzer pin to output pinmode(buzzerpin, OUTPUT); void loop(){ //for loop to loop around notes for(int i = 0; i < 7; i++){ tone(buzzerpin,notes[i]); delay(400); This code has used external library functions, if statements, arrays and modulo. Let s quickly run over what they are; External library: How we use premade functions in our code. We must create an Object of the library and initialise it. For loops: For loops are how we create set length loops within our project. Unlike void loop (which loops infinitely) for loops have a duration set in the brackets. for(int i = 0; i < 7; i++){ In this instance, the loop will happen 7 times, executing the function within the curly brackets. Page 3 - Start Arduino Course: 06 Buzzer

4 Circuit Buzzer with tilt mute Hardware As mentioned, we re going to expand on this and make an instrument with our sensors. These can be used to control a variety of things eg: Mute, Pitch, Speed, length etc. For this, we will need: 1x Arduino Uno 1x USB Cable 1x Piezo Buzzer 1x Tilt Switch 6x Jumper Wire 1x 10 k Ohm Resistor (Orange Black Brown Gold) 1x 220 Ohm Resistor (Red Red Brown Gold) Here s a simple addition of a sensor to the original tone circuit, so we can use the tilt switch to act as a mute. The sequence will play through before muting. Page 4 - Start Arduino Course: 06 Buzzer

5 Circuit Buzzer Code Make a new sketch in the Arduino IDE and name this Buzzer_tilt. We have added an if statement to check if the digital Pin the tilt switch is receiving a voltage or not. This is because the tilt switch is making a complete circuit when the tilt switch is not tilted. //array of musical notes int notes[] = { 220, 440, 660, 880, 1100, 1320, 1540 ; //variable to store buzzer pin int buzzerpin = 11; //set up piezo transducer pin int tilt = 10; //variable to store value int tilt_value; void setup() { //set buzzer pin to output pinmode(buzzerpin, OUTPUT); //set tilt pin to input pinmode(tilt, INPUT); void loop() { //for loop to loop around notes tilt_value = digitalread(tilt); if (tilt_value == HIGH) { for (int i = 0; i < 7; i++) { tone(buzzerpin, notes[i]); delay(400); else { notone(buzzerpin); Page 5 - Start Arduino Course: 06 Buzzer

6 Once you have copied the code, press (upload) and watch the results! (compile) and if no errors appear, press My code won t compile! Is everything spelt correctly? Are all your lines ending in a semi-colon? Do you have the correct capital letters? Did you close the curly brackets? Buzzer Instrument Challenge Now it s your turn to use the skills you ve learn to create an instrument. One function what will help is Arduino map() function. This will help map analog values (0 1023) to tone functions. int outcome - map(int input, int min_input, int max_input, int min_output, int max_output); Some functions and routines that you could use: Some ideas you could use: Push button for each note using push button circuit and if statements. Thermistor controlled theremin. if(this < that){ //Do function Door bell melody triggered by Piezo transducer. Potentiometer controlled delay melody. Serial controlled melody Servo robot. for(int this = 0; this < that; this++){ //Do function that amount of time Page 6 - Start Arduino Course: 06 Buzzer