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sync update
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@nkolban
nkolban committed Mar 14, 2016
1 parent 6859090 commit 4761d5c
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17 changes: 9 additions & 8 deletions README.md
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Expand Up @@ -81,14 +81,15 @@ is specified by the number of pins supplied in the `setup` call.

In summary, the methods are:

| Method | Description |
|---------------------------|---------------------------|
| `setSpeed(rpm)` | Set the speed of rotation |
| `forward()` | Start rotating forwards |
| `backward()` | Start rotating backwards |
| `stop()` | Stop rotating |
| `step(steps, [callback])` | Step the motor |

| Method | Description |
|--------------------------------------------------------------|----------------------------|
| `setup(stepsInRevolution, pin1, pin2, [pin3, pin4, [pin5]])` | Setup the motor |
| `setSpeed(rpm)` | Set the speed of rotation |
| `forward()` | Start rotating forwards |
| `backward()` | Start rotating backwards |
| `stop()` | Stop rotating |
| `step(steps, [callback])` | Step the motor |
| `halt()` | Halt the motor (free turn) |

## Dependencies
This package depends upon:
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114 changes: 81 additions & 33 deletions src/stepper-wiringpi.js
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@@ -1,7 +1,7 @@
/**
* stepper-wiringpi
* A module that moves a stepper motor for the Raspberry Pi based on the Wiring-Pi
* module for GPIO access.
* module for GPIO access. See the README.md file for usage details.
*
* Based on the design and implementation of the Arduino Stepper class found here:
*
Expand All @@ -12,14 +12,24 @@
*/


const wpi = require('wiring-pi');
var wpi = require('wiring-pi');

wpi.setup('gpio');


// Create definitions for the constants.
var FORWARD = 1;
var BACKWARD = -1;

// Publish the constants.
exports.FORWARD = FORWARD;
exports.BACKWARD = BACKWARD;

// A global used to identify motors for debugging purposes. The first motor created
// will have index 1, the next will have index 2 and so on.
var motorIndex=1;


function setup2Wire(motorPin1, motorPin2)
{
// Pi pins for the motor control connection:
Expand Down Expand Up @@ -93,14 +103,19 @@ exports.setup = function(stepsPerRevolution, motorPin1, motorPin2, motorPin3, mo
forward: forward, // Function
backward: backward, // Function
stop: stop, // Function
halt: halt, // Function

_motorIndex: motorIndex, // The index of the motor used for debugging purposes.
_stepDelay: 60*1000/stepsPerRevolution, // Set the default step delay to 1 rpm.
_stepNumber: 0, // Which step the motor is on.
_direction: 0, // Motor direction.
_timerId: null,
_moveTimeoutId: null,
_direction: FORWARD, // Motor direction.
_timerId: null, // Interval object for stepping fixed number of steps.
_moveTimeoutId: null, // Timeout object for continuous rotation
_stepsPerRevolution: stepsPerRevolution // Total number of steps for this motor.
}

motorIndex++; // Increment the global motorIndex count (used for debugging).

// Determine whether we are being called with 2,4 or 5 pins and setup accordingly.
if (motorPin3 == undefined) {
setup2Wire.call(context, motorPin1, motorPin2);
Expand All @@ -114,7 +129,8 @@ exports.setup = function(stepsPerRevolution, motorPin1, motorPin2, motorPin3, mo


/**
* Sets the speed in revs per minute
* PUBLIC:
* Sets the speed in revolutions per minute (RPM)
*/
function setSpeed(desiredRPM)
{
Expand All @@ -141,6 +157,7 @@ function setSpeed(desiredRPM)
this._stepDelay = maxRPM / desiredRPM;
} // End of setSpeed


//PUBLIC: Set the motor to rotate forwards at the current set speed.
function forward() {
stop.call(this);
Expand All @@ -158,11 +175,11 @@ function move(direction) {
//console.log("move: direction: %d", direction);
//console.log("move: %j", this);
if (direction == FORWARD) {
this._stepNumber++;
incrementStepNumber.call(this);
} else {
this._stepNumber--;
decrementStepNumber.call(this);
}
//console.log("Step number: %d", this._stepNumber);
console.log("Step number: %d", this._stepNumber);
stepMotor.call(this, this._stepNumber);
this._moveTimeoutId = setTimeout(move.bind(this), this._stepDelay, direction);
}
Expand All @@ -176,7 +193,8 @@ function stop() {
}

/**
* Moves the motor stepsToMove steps. If the number is negative,
* PRIVATE:
* Moves the motor a fixed number of steps defined by `stepsToMove`. If the number is negative,
* the motor moves in the reverse direction. The optional callback
* function will be invoked when the number of steps being asked to
* be moved have been moved.
Expand All @@ -193,14 +211,16 @@ function step(stepsToMove, callback)
var stepsLeft = Math.abs(stepsToMove); // how many steps to take

// determine direction based on whether stepsToMove is + or -:
if (stepsToMove > 0) { this._direction = 1; }
if (stepsToMove < 0) { this._direction = 0; }
if (stepsToMove > 0) { this._direction = FORWARD; }
if (stepsToMove < 0) { this._direction = BACKWARD; }

// If we should already be in the middle of a movement, cancel it.
if (this._timerId != null) {
clearInterval(this._timerId);
}

stop(); // If we are in a continuous rotation ... stop that too.

// Note: A question comes up on scheduling the first move immediately
// as opposed to a stepDelay later. We should always pause at least
// one stepDelay even for the first step. Consider what would happen
Expand All @@ -214,46 +234,74 @@ function step(stepsToMove, callback)
// we started.
this._timerId = setInterval(function()
{
// If we have moved the correct number of steps then cancel the timer and return
// after invoking a callback (if one has been supplied).
if (stepsLeft <= 0) {
clearInterval(this._timerId);
this._timerId = null;
if (callback != null) {
callback();
}
return;
} // End of stepsLeft <= 0

// increment or decrement the step number, depending on direction:
if (this._direction == 1)
if (this._direction == FORWARD)
{
this._stepNumber++;
if (this._stepNumber == this._stepsPerRevolution) {
this._stepNumber = 0;
}
incrementStepNumber.call(this);
}
else
{
if (this._stepNumber == 0) {
this._stepNumber = this._stepsPerRevolution;
}
this._stepNumber--;
decrementStepNumber.call(this);
}

// step the motor to step number 0, 1, ..., {3 or 10}
stepMotor.call(this, this._stepNumber);

// Decrement the steps left to move. If we have moved the correct number
// of steps, cancel the timer as there is no need to move anymore.
stepsLeft--;
if (stepsLeft <= 0) {
clearInterval(this._timerId);
this._timerId = null;
if (callback != null) {
callback();
}
} // End of stepsLeft == 0
stepsLeft--; // Decrement the steps left to move.

}.bind(this), this._stepDelay); // End of setInterval
} // End of step


// PUBLIC:
// Halt the motors by setting all the voltages to low. There will now be no
// force restricting the movement of the motors.
function halt() {
wpi.digitalWrite(this._motorPin1, wpi.LOW);
wpi.digitalWrite(this._motorPin2, wpi.LOW);
if (this._pinCount == 2 || this._pintCount == 4) {
wpi.digitalWrite(this._motorPin3, wpi.LOW);
wpi.digitalWrite(this._motorPin4, wpi.LOW);
}
if (this._pinCount == 5) {
wpi.digitalWrite(this._motorPin5, wpi.LOW);
}
} // End of halt


function incrementStepNumber() {
this._stepNumber++;
if (this._stepNumber >= this._stepsPerRevolution) {
this._stepNumber = 0;
}
}

function decrementStepNumber() {
this._stepNumber--;
if (this._stepNumber < 0) {
this._stepNumber = this._stepsPerRevolution - 1;
}
}

/*
* PRIVATE:
* Moves the motor forward or backwards.
*/
function stepMotor(thisStep)
{
thisStep = Math.abs(thisStep);
//console.log("Step: %d, mod4=%d, pinCount=%d", thisStep, thisStep%4, this._pinCount);
console.log("Step: %d, \tmod4=%d", thisStep, thisStep%4);

if (this._pinCount == 2) {
switch (thisStep % 4) {
Expand Down Expand Up @@ -378,4 +426,4 @@ function stepMotor(thisStep)
}
}
} // End of stepMotor
// End of file
// End of file
51 changes: 51 additions & 0 deletions tests/test5.js
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@@ -0,0 +1,51 @@
/**
* Sample for the stepper-wiringpi.js.
*
* Here we are testing a Stepper motor that has 200 steps per revolution
* which equates to 360/200 = 1.8 degrees per step.
*/

var wpi = require("wiring-pi");
wpi.setup("gpio");
wpi.pcf8574Setup(100, 0x20);

// In this test we are going to use a PCF8574 for control and control
// two motors
console.log("Starting stepper-wiringpi - test5");

var stepperWiringPi = require("../src/stepper-wiringpi");
var m1pinIN1 = 100; // Stepper Red
var m1pinIN2 = 101; // Stepper Blue
var m1pinIN3 = 102; // Stepper Green
var m1pinIN4 = 103; // Stepper Black

var m2pinIN1 = 104; // Stepper Red
var m2pinIN2 = 105; // Stepper Blue
var m2pinIN3 = 106; // Stepper Green
var m2pinIN4 = 107; // Stepper Black

var motor1 = stepperWiringPi.setup(200, m1pinIN1, m1pinIN2, m1pinIN3, m1pinIN4);
var motor2 = stepperWiringPi.setup(200, m2pinIN1, m2pinIN2, m2pinIN3, m2pinIN4);
var direction = 1;
console.log("Globals: FORWARD=%d, BACKWARD=%d", stepperWiringPi.FORWARD, stepperWiringPi.BACKWARD);

function changeDirection() {
console.log("Changing direction from %d", direction);
if (direction == stepperWiringPi.FORWARD) {
direction = stepperWiringPi.BACKWARD;
motor1.backward();
motor2.backward();
} else {
direction = stepperWiringPi.FORWARD;
motor1.forward();
motor2.forward();
}
setTimeout(changeDirection.bind(this), 2000);
}

motor1.setSpeed(20);
motor2.setSpeed(60);

changeDirection();

console.log("Step requested submitted.");

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