Code
Verbinde Arduino mit einem Knopf und zähle, wie oft der Knopf gedrückt wird
State change detection (edge detection)
Often, you don't need to know the state of a digital input all the time, but
you just need to know when the input changes from one state to another.
For example, you want to know when a button goes from OFF to ON. This is called
state change detection, or edge detection.
This example shows how to detect when a button or button changes from off to on
and on to off and how to count these changes.
The circuit:
- pushbutton attached to pin 2 from +5V
- 10 kilohm resistor attached to pin 2 from ground
by Tom Igoe
This example code is in the public domain.
http://www.arduino.cc/en/Tutorial/ButtonStateChange
// this constant won't change:
const int buttonPin = 2; // the pin that the pushbutton is attached to
// Variables will change:
int buttonPushCounter = 0; // counter for the number of button presses
int buttonState = 0; // current state of the button
int lastButtonState = 0; // previous state of the button
void setup() {
// initialize the button pin as a input:
pinMode(buttonPin, INPUT);
// initialize the LED as an output:
//pinMode(ledPin, OUTPUT);
// initialize serial communication:
Serial.begin(9600);
}
void loop() {
// read the pushbutton input pin:
buttonState = digitalRead(buttonPin);
// compare the buttonState to its previous state
if (buttonState != lastButtonState) {
// if the state has changed, increment the counter
if (buttonState == HIGH) {
// if the current state is HIGH then the button went from off to on.
Serial.println("on");
Serial.print("number of button pushes: ");
Serial.println(buttonPushCounter);
} else {
// if the current state is LOW then the button went from on to off:
Serial.println("off");
Serial.println(" ");
}
// Delay a little bit to avoid inaccurate counting.
delay(50);
}
// save the current state as the last state, for next time through the loop
lastButtonState = buttonState;
}
Führe eine Funktion einmalig aus, wenn ein Button gedrückt ist, und einmalig etwas anderes, wenn er losgelassen wird
int buttonDown =0;
int inputPin = 5; //hier muss der Pin eingetragen sein, an dem der Button hängt
[...]
void loop(){
if (digitalRead(inputPin)==LOW){
buttonDown++;
}
if (buttonDown==1){
DoSomethingOnceWhenPressed();
}
if (digitalRead(inputPin)==HIGH && buttonDown>0){
DoSomethingOnceWhenReleased();
buttonDown=0;
}
}
Mache etwas alle x-Durchläufe
int loopCounter=0;
int alleXLoops = 15; //Führt eine Funktion alle 15 loops aus
[...]
void loop(){
loopCounter++;
if (loopCounter%alleXLoops==0){
DoSomethingEveryXLoops();
}
}