johnny-five/docs/button-pullup.md

The JavaScript Arduino Programming Framework.

# Button Pullup

Run with:
```bash
node eg/button-pullup.js
```


```javascript
// The `isPullup` button option enables the pullup
// resistor on the pin and automatically sets the
// `invert` option to true

// In this circuit configuration, the LED would always
// be on without the pullup resistor enabled

// For more info on pullup resistors, see:
// http://arduino.cc/en/Tutorial/InputPullupSerial
// http://arduino.cc/en/Tutorial/DigitalPins
// https://learn.sparkfun.com/tutorials/pull-up-resistors

var five = require("../lib/johnny-five"),
  button, led;

five.Board().on("ready", function() {

  button = new five.Button({
    pin: 2,
    isPullup: true
  });

  led = new five.Led(13);

  button.on("down", function(value) {
    led.on();
  });

  button.on("up", function() {
    led.off();
  });

});

```


## Breadboard/Illustration


![docs/breadboard/button-pullup.png](breadboard/button-pullup.png)









## Contributing
All contributions must adhere to the [Idiomatic.js Style Guide](https://github.com/rwldrn/idiomatic.js),
by maintaining the existing coding style. Add unit tests for any new or changed functionality. Lint and test your code using [grunt](https://github.com/cowboy/grunt).

## License
Copyright (c) 2012 Rick Waldron <waldron.rick@gmail.com>
Licensed under the MIT license.