Arduino: A new & improved Button library with some handy features
By Ted Hayes, from code originally by Alexander Brevig & Tom Igoe
The Arduino Button library (Github Repo) makes it easy to do some very common but rather tedious tasks. Usually when you interact with a button (such as a momentary switch), you mainly want to detect the state change, not just the current state. You have to do something like:
int lastState = 0;
void loop(){
int currentState = digitalRead(11);
if(currentState != lastState){
// do something
}
lastState = currentState;
}
It’s not hard, just tedious. This new and improved Button library makes this much simpler but adds so much more. Now you can do it this way:
Button button = Button(12);
void onPress(Button& b){
Serial.print("onPress: ");
Serial.println(b.pin);
// will print out "onPress: 12"
}
void setup(){
Serial.begin(9600);
// Assign callback function
button.pressHandler(onPress);
}
void loop(){
// update the buttons' internals
button.process();
}
Features
- Object-oriented design
Button myButton(11);
- Automatic pull-up setting
Button myButton(11, BUTTON_PULLUP_INTERNAL);
- Simplified state-change detection:
if(button.isPressed()) ...
- Callback model
button.pressHandler(onPress)
- Built-in debouncing
// Sets 50ms debounce duration Button button = Button(12, BUTTON_PULLUP_INTERNAL, true, 50);
Installing
To install, download the library, extract it to ~/Documents/Arduino/libraries and rename the folder “Button.” (Github generates a different name for the zip link.) Restart Arduino if it was already open.
I hope you find this useful! Please report any bugs using the Github issue tracker.
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