ShiftRegister

The ShiftRegister class constructs an object that represents a shift register.

Parameters

• pins An array of pins in data, clock, latch, [reset] order

• options An object of constructor parameters

  Name	Type	Value/Description	Default	Required
  pins	Object	{data, clock, latch, [reset]}		Yes (either)
  pins	Array	[data, clock, latch, [reset]]		Yes (either)
  isAnode	Boolean	true or false. Initialize shift register to output for common anode device.	false	No

Shape

Property Name	Description	Read Only
id	A user definable id value. Defaults to a generated uid	No
pins	the object containing the pin values for data, clock and latch	No
value	the object containing the pin values for data, clock and latch	Yes
isAnode	the object containing the pin values for data, clock and latch	Yes

Component Initialization

Default

new five.ShiftRegister({
  pins: {
    data: 2,
    clock: 3,
    latch: 4
  }
});

new five.ShiftRegister({
  pins: [2, 3, 4]
});

new five.ShiftRegister([2, 3, 4]);

Common Anode

new five.ShiftRegister({
  isAnode: true,
  pins: {
    data: 2,
    clock: 3,
    latch: 4
  }
});

new five.ShiftRegister({
  isAnode: true,
  pins: [2, 3, 4]
});

Usage

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

board.on("ready", function() {
  var register = new five.ShiftRegister({
    isAnode: true,
    pins: {
      data: 2,
      clock: 3,
      latch: 4,
      reset: 9,
    }
  });
  var number = 0;
  var decimal = 0;

  register.reset();

  // Display numbers 0-9, one at a time in a loop.
  // Shows just the number for a half second, then
  // the number + a decimal point for a half second.
  setInterval(function() {
    register.display(number + (decimal && "."));

    if (decimal) {
      number++;
    }

    if (number > 9) {
      number = 0;
    }

    decimal ^= 1;
  }, 500);
});

API

• clear() Clear the register.

• display(number) Display a number on a seven segment display.

  // Display a 1 on a single seven segment controlled
  // by the shift register.
  register.display(1);

• display(string) Display a number on a seven segment display, optionally including the decimal point.

  // Display a 1 on a single seven segment controlled
  // by the shift register. The decimal point will also be lit
  register.display("1.");
  
  // Display a 1 on a single seven segment controlled
  // by the shift register. The decimal point will NOT be lit
  register.display("1");

• reset() Reset the register.

• send(B) Send an 8-bit byte value to the shift register.

• send([B1, B2]) Send an array of 8-bit byte values to the shift register.

Events

ShiftRegister objects are output only and therefore do not emit any events.