Rick Waldron edited this page Aug 19, 2018 · 17 revisions

The Boards class constructs a collection object containing multiple board objects. If no arguments are passed, Board objects will be created for every board detected in the order that the system enumerates them.

See also:

Parameters

  • ports A list of port objects or port address strings. Port objects may have the following properties:

    Property Type Value/ Description Default Required
    id Number, String Any. User definable identification Generated no
    port String /dev/ttyAM0, COM1. Path or name of device port/COM Detected no

Component Initialization

The easiest way to initialize multiple board objects is to call the Boards constructor function with new. Don't worry about knowing your device's path or COM port, Johnny-Five will figure out which USBs are in use by compatible boards automatically.

Specified IDs

// Create 2 board instances with IDs "A" & "B" 
// (ports will be initialized in device enumeration order)
new five.Boards([ "A", "B" ]);

Specified Ports

// Create 2 board instances on ports 
// "/dev/cu.usbmodem621" and "/dev/cu.usbmodem411"
new five.Boards([ "/dev/cu.usbmodem621", "/dev/cu.usbmodem411" ]);

Specified IDs & Ports

var ports = [
  { id: "A", port: "/dev/cu.usbmodem621" },
  { id: "B", port: "/dev/cu.usbmodem411" }
];

new five.Boards(ports);

Usage

A basic, but complete example usage of the Boards constructor:

// Create 2 board instances with IDs "A" & "B"
new five.Boards([ "A", "B" ]).on("ready", function() {

  // Both "A" and "B" are initialized
  // (connected and available for communication)

  // |this| is an array-like object containing references
  // to each initialized board.
  this.each(function(board) {

    // Initialize an Led instance on pin 13 of
    // each initialized board and strobe it.
    new five.Led({ pin: 13, board: board }).strobe();
  });
});

Override this by providing explicit port paths:

var ports = [
  { id: "A", port: "/dev/cu.usbmodem621" },
  { id: "B", port: "/dev/cu.usbmodem411" }
];

new five.Boards(ports).on("ready", function() {

  // Both "A" and "B" are initialized
  // (connected and available for communication)

  // |this| is an array-like object containing references
  // to each initialized board.
  this.each(function(board) {

    // Initialize an Led instance on pin 13 of
    // each initialized board and strobe it.
    new five.Led({ pin: 13, board: board }).strobe();
  });
});

API

each(callback(board, index)) Call a function once for each board object.

Events

  • ready Once the board objects have been initialized, they must connect to the physical boards with a set of handshake steps, once this has completed, the boards are ready to communicate with the program. This process is asynchronous, and signified to the program via a "ready" event.

    // Create 2 board instances with IDs "A" & "B"
    new five.Boards([ "A", "B" ]).on("ready", function() {
    
      // Both "A" and "B" are initialized
      // (connected and available for communication)
    
    });

    Override this by providing explicit port paths:

    var ports = [
      { id: "A", port: "/dev/cu.usbmodem621" },
      { id: "B", port: "/dev/cu.usbmodem411" }
    ];
    
    new five.Boards(ports).on("ready", function() {
    
      // Both "A" and "B" are initialized
      // (connected and available for communication)
    
    });

NOTE When using multiple boards, all device classes must be initialized with an explicit reference to the board object that they will be associated to. This is illustrated in the previous code example.

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