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Rick Waldron edited this page Feb 23, 2015 · 28 revisions

The Pin class constructs objects that represent any one pin on the physical board.

For most cases, a proper Component class should be used instead of Pin.

Parameters

  • pin A Number or String address for the pin. If digital, use the number, if analog use the "A" prefixed string.

  • options An object of property parameters.

    Property Name Type Value(s) Description Required
    id Number, String Non-specific Any string or number value. Defaults to null no
    pin Number, String Any Pin The Number or String address of the pin yes
    type String "digital", "analog" For most cases, this can be omitted; the type will be inferred based on the pin address number. no

Shape

{ 
  id: A user definable id value. Defaults to null
  pin: The pin address of the pin
  type: The type of pin this is, either "digital" or "analog"
  value: The most recently reported value for this pin.
}

Component Initialization

var digital = new five.Pin(13);

var analog = new five.Pin("A0");
var digital = new five.Pin({
  pin: 13
});

var analog = new five.Pin({
  pin: "A0"
});

var analogAsDigital = new five.Pin({
  pin: 14,
  type: "digital"
});

Usage

var five = require("johnny-five");
var board = new five.Board();

board.on("ready", function() {
  var strobe = new five.Pin(13);
  var state = 0x00;

  this.loop(500, function() {
    strobe.write(state ^= 0x01);
  });
});

API

  • query(callback(value)) Query the board for the current state of this pin, invoking callback with argument state when complete.

    var pin = new five.Pin(13);
    
    pin.query(function(state) {
      console.log(state);
    });

    An example pin state object looks like:

    { 
      supportedModes: [ 0, 1, 3, 4 ],
      mode: 0,
      value: 0,
      report: 1,
      analogChannel: 127 
    }

    Modes

    Mode Value Constant
    INPUT 0 Pin.INPUT
    OUTPUT 1 Pin.OUTPUT
    ANALOG 2 Pin.ANALOG
    PWM 3 Pin.PWM
    SERVO 4 Pin.SERVO
  • high() Set the pin HIGH.

    var pin = new five.Pin(13);
    // This will set pin 13 high (on)
    pin.high();
    pin.high();
  • low() Set the pin LOW.

    var pin = new five.Pin(13);
    // This will set pin 13 low (off)
    pin.low();
  • write(value) Write a value to this pin.

    var pin = new five.Pin(13);
    
    pin.write(1);
  • read(callback(error, value)) Register a handler to be called whenever the board reports the value (digital or analog) of this pin.

    var pin = new five.Pin(13);
    
    pin.read(function(error, value) {
      console.log(value);
    });

Events

Whenever a pin is set to INPUT or ANALOG, it will automatically emit the following events:

  • high The "high" event is emitted whenever the pin goes high.

  • low The "low" event is emitted whenever the pin goes low.

  • data The "data" event is emitted for every all data (firehose).

Static

Modes

Mode Value Constant
INPUT 0 Pin.INPUT
OUTPUT 1 Pin.OUTPUT
ANALOG 2 Pin.ANALOG
PWM 3 Pin.PWM
SERVO 4 Pin.SERVO

Methods

  • Pin.write(pin, value) Write a value to a pin.

    // This will set pin 13 High
    five.Pin.write(13, 1);
  • Pin.read(pin, callback) Register a handler to be called whenever the board reports the value (digital or analog) of the specified pin.

    five.Pin.read(13, function(error, value) {
      console.log(value);
    });

Examples

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