Arduino Uno Quick Start Manual page 69

BinaryDice/SimpleButton/SimpleButton.ino
const unsigned int
const unsigned int
void setup() {
pinMode(LED_PIN, OUTPUT);
pinMode(BUTTON_PIN, INPUT);
}
void loop() {
const int BUTTON_STATE = digitalRead(BUTTON_PIN);
if (BUTTON_STATE == HIGH)
digitalWrite(LED_PIN, HIGH);
else
digitalWrite(LED_PIN, LOW);
}
We connect the button to pin 7 and the LED to pin 13 and initialize those
pins in the function. In
setup
to the button. If it is
Upload the program to the Arduino, and you ll see that the LED is on as long
as you press the button. As soon as you release the button, the LED turns
off. This is pretty cool, because now we nearly have everything we need to
control our die using our own button. But before we proceed, we ll slightly
enhance our example and turn the button into a real light switch.
To build a light switch, we start with the simplest possible solution. Do not
change the current circuit, and upload the following program to your Arduino:
BinaryDice/UnreliableSwitch/UnreliableSwitch.ino
const unsigned int
Line 1
const unsigned int
-
-
void setup() {
-
pinMode(LED_PIN, OUTPUT);
5
pinMode(BUTTON_PIN, INPUT);
-
}
-
int led_state = LOW;
-
void loop() {
-
const int CURRENT_BUTTON_STATE = digitalRead(BUTTON_PIN);
10
if (CURRENT_BUTTON_STATE == HIGH) {
-
if (led_state == LOW)
-
led_state = HIGH;
-
else
-
led_state = LOW;
15
digitalWrite(LED_PIN, led_state);
-
}
-
}
-
BUTTON_PIN = 7;
LED_PIN = 13;
, we read the current state of the pin connected
loop
HIGH , we turn the LED on. Otherwise, we turn it off.
BUTTON_PIN = 7;
LED_PIN = 13;
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Chapter 3. Building Binary Dice 50
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