Pin

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	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, defaults to 0, or addr when that is supplied	no
  type	String	"digital", "analog"	For most cases, this can be omitted; the type will be inferred based on the pin address number.	no
  mode	Number	0 .. 4	The available mode constants are described further down the page. If not specified, mode defaults to 1 or 2 depending on type	no
  addr	Number, String	Any Pin	The Number or String address of the pin	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.
  mode: The mode (number) for the pin.  See "Modes" below
}

Component Initialization

Basic

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

• Pin
• Pin Circuit Event