JavaScript Robotics: Stepper API (Johnny-Five)

Parameters
Shape
Component Initialization
Usage
API
Events

The Stepper class constructs objects that represent a single stepper motor attached to the physical board. This class is new and should be considered unstable.

In order to use the Stepper class, your board must be flashed with AdvancedFirmata, which is available here: https://github.com/soundanalogous/AdvancedFirmata

Stepper motors generally require significantly involved hardware setup (that is, more than just plugging a single lead into a pin).

Parameters

options An object of property parameters.

Property	Type	Value/Description	Default	Required
pins	Object *	See Table. An object containing the named pin addresses for the 3 supported types		yes *
pins	Array *	See Table. An array containing the pin addresses for the 3 supported types		yes¹
stepsPerRev	Number	Steps per revolution. This will differ by motor, refer to motor specs for value		yes
type	constant	`five.Stepper.TYPE.DRIVER`, `five.Stepper.TYPE.TWO_WIRE`, `five.Stepper.TYPE.FOUR_WIRE`		yes
rpm	Number	Revolutions per minute, used to calculate speed.	180	no
direction	constant	`five.Stepper.DIRECTION.CW`, `five.Stepper.DIRECTION.CCW`		no²

Pins

Config	As Object	As Array
DRIVER	`{ step, dir }`	`[ step, dir ]`
TWO_WIRE	`{ m1, m2 }`	`[ m1, m2 ]`
FOUR_WIRE	`{ m1, m2, m3, m4 }`	`[ m1, m2, m3, m4 ]`

The pins property is required, but can be EITHER an object or an array.
The direction property is not required, but if it is undefined then Stepper.step() will do nothing.

Shape

{
  id: A user definable id value. Defaults to a generated uid
  pins: Object containing the pin addresses for the Stepper
  rpm: Revolutions per minute, used to calculate speed. Defaluts to 180
  direction:
  speed:
  accel:
  decel:
}

Component Initialization

Driver

// Create a stepper motor
//
//   - Step on pin 11
//   - Direction on pin 12
//   - Steps per revolution: 200
//   - Uses a Driver board
//

new five.Stepper({
  type: five.Stepper.TYPE.DRIVER,
  stepsPerRev: 200,
  pins: [ 11, 12 ]
});

// Is the same as...

five.Stepper({
  type: five.Stepper.TYPE.DRIVER
  stepsPerRev: 200,
  pins: {
    step: 11
    dir: 12
  }
 });

five.Stepper({
  type: five.Stepper.TYPE.DRIVER
  stepsPerRev: number,
  pins: {
    step: number
    dir: number
  }
 });

five.Stepper({
  type: five.Stepper.TYPE.DRIVER
  stepsPerRev: number,
  pins: [ step, dir ]
});

Stepper.Stepper.TYPE.DRIVER

TWO WIRE

five.Stepper({
  type: five.Stepper.TYPE.TWO_WIRE
  stepsPerRev: number,
  pins: {
    motor1: number,
    motor2: number
  }
 });

five.Stepper({
  type: five.Stepper.TYPE.TWO_WIRE
  stepsPerRev: number,
  pins: [ motor1, motor2 ]
});

FOUR WIRE

five.Stepper({
  type: five.Stepper.TYPE.FOUR_WIRE
  stepsPerRev: number,
  pins: {
    motor1: number,
    motor2: number,
    motor3: number,
    motor4: number
  }
});

five.Stepper({
  type: five.Stepper.TYPE.FOUR_WIRE
  stepsPerRev: number,
  pins: [ motor1, motor2, motor3, motor4 ]
});

Stepper.Stepper.TYPE.DRIVER

Usage

var board = new five.Board();

board.on("ready", function() {
  var k = 0;
  var stepper = new five.Stepper({
    type: five.Stepper.TYPE.DRIVER,
    stepsPerRev: 200,
    pins: [11, 12]
  });

  stepper.rpm(180).ccw().step(2000, function() {
    console.log("done");
  });
});

API

step(stepsOrOpts, callback) Move a stepper motor.

// stepsOrOpts
{
  steps: number of steps to move
  direction: 1, 0 (CCW, CW)
  rpm: Revolutions per minute. Defaults to 180
  accel: Number of steps to accelerate
  decel: Number of steps to decelerate
}

//
//   - 10 full revolutions
//   - Clockwise
//   - Accelerate over the first 1600 steps
//   - Decelerate over the last 1600 steps
//

stepper.step({ steps: 2000, direction: 1, accel: 1600, decel: 1600 }, function() {
  console.log("Done stepping!");
});

rpm() Get the rpm.

rpm(value) Set the rpm.

stepper.rpm(180).step(2000, function() {
  console.log("Done stepping!");
});

speed() Get the speed.

speed(value) Set the speed in 0.01 * rad/s.

// 180 rpm
stepper.speed(0.18850).step(2000, function() {
  console.log("Done stepping!");
});

direction() Get the direction.

direction(value) Set the direction.

stepper.direction(1).step(2000, function() {
  console.log("Done stepping!");
});

stepper.direction(0).step(2000, function() {
  console.log("Done stepping!");
});

Or...

stepper.direction(five.Stepper.DIRECTION.CW).step(2000, function() {
  console.log("Done stepping!");
});

stepper.direction(five.Stepper.DIRECTION.CCW).step(2000, function() {
  console.log("Done stepping!");
});

accel() Get the acceleration.

accel(value) Set the acceleration.

stepper.accel(1600).step(2000, function() {
  console.log("Done stepping!");
});

decel() Get the deceleration.

decel(value) Set the deceleration.

stepper.decel(1600).step(2000, function() {
  console.log("Done stepping!");
});

cw() Set the Stepper to move Clockwise.
```
stepper.cw().step(2000);
```
ccw() Set the Stepper to move Counter-Clockwise.
```
stepper.ccw().step(2000);
```

Static

Types

Type	Value	Constant
DRIVER	1	Stepper.TYPE.DRIVER
DRIVER	2	Stepper.TYPE.TWO_WIRE
DRIVER	4	Stepper.TYPE.FOUR_WIRE

Run States

State	Value	Constant
STOP	0	Stepper.RUNSTATE.STOP
DRIVE	1	Stepper.RUNSTATE.ACCEL
DRIVE	2	Stepper.RUNSTATE.DECEL
DRIVE	3	Stepper.RUNSTATE.RUN

Directions

Direction	Value	Constant
CCW	0	Stepper.DIRECTION.CCW
CW	1	Stepper.DIRECTION.CW