If you feel the initial example is a bit underwhelming ("I don't need a metro to do this!"), let's use the metro to do something a bit more complicated. We are going to make a light-switch. One of the buttons on your breadboard is going to turn on the light, and the other is going to turn it off!
This is super simple, we're just going to change a few lines of code:
int ledPin = 13; // choose the pin for the LED
int buttonPin1 = 3; // button 1
int buttonPin2 = 2; // button 2
void setup() {
pinMode(ledPin, OUTPUT); // declare LED as output
pinMode(buttonPin1, INPUT); // make button 1 an input
pinMode(buttonPin2, INPUT); // make button 2 an input
}
void loop() {
if (digitalRead(buttonPin1) == LOW) {
digitalWrite(ledPin, LOW); // turn LED OFF
}
else if (digitalRead(buttonPin2) == LOW) {
digitalWrite(ledPin, HIGH); // turn LED ON
}
}
Copy and paste the code into a blank sketch, upload it to the board, and start toggling the LED on and off.
Let's use the buttons to control an analog signal. To do this, you will need to change the wire connecting the LED from Pin 13 to Pin 9.
In the code, change:
int ledPin = 13; -> int ledPin = 9;
Next, change the loop() code to read:
int value = 0;
void loop() {
if(digitalRead(buttonPin1) == LOW){
value--;
}
else if(digitalRead(buttonPin2) == LOW){
value++;
}
value = constrain(value, 0, 255);
analogWrite(ledPin, value);
delay(10);
}
