duino

A framework for working with Arduinos in node.js

install

npm install duino

usage

var arduino = require('duino'),
    board = new arduino.Board();

var led = new arduino.Led({
  board: board,
  pin: 13
});

led.blink();

what ಠ_ಠ

The way this works is simple (in theory, not in practice). The Arduino listens for low-level signals over a serial port, while we abstract all of the logic on the Node side.

1. Plug in your Arduino
2. Upload the C code at ./src/du.ino to it
3. Write a simple duino script
4. ?????
5. Profit!

libraries

##board

Right now, the board library will attempt to autodiscover the Arduino. I'm going to make it configurable, don't worry.

var board = new arduino.Board({
  debug: true
});

Debug mode is off by default. Turning it on will enable verbose logging in your terminal, and tell the Arduino board to echo everthing back to you. You will get something like this:

The board object is an EventEmitter. You can listen for the following events:

• data messages from the serial port, delimited by newlines
• connected when the serial port has connected
• ready when all internal post-connection logic has finished and the board is ready to use

board.on('ready', function(){
  // do stuff
});

board.on('data', function(m){
  console.log(m);
}

###board.serial

Low-level access to the serial connection to the board

###board.write(msg)

Write a message to the board, wrapped in predefined delimiters (! and .)

###board.pinMode(pin, mode)

Set the mode for a pin. mode is either 'in' or 'out'

###board.digitalWrite(pin, val)

Write one of the following to a pin:

####board.HIGH and board.LOW

Constants for use in low-level digital writes

###board.analogWrite(pin,val)

Write a value between 0-255 to a pin

##led

var led = new arduino.Led({
  board: board,
  pin: 13
});

Pin will default to 13.

###led.on()

Turn the LED on

###led.off()

Turn the LED off

###led.blink(interval)

Blink the LED at interval ms. Defaults to 1000

###led.fade(interval)

Fade the to full brightness then back to minimal brightness in interval ms. Defaults to 2000

###led.bright

Current brightness of the LED

##lcd

This is a port of the LiquidCrystal library into JavaScript. Note that communicating with the LCD requires use of the synchronous board.delay() busy loop which will block other node.js events from being processed for several milliseconds at a time. (This could be converted to pause a board-level buffered message queue instead.)

var lcd = new d.LCD({
  board: board,
  pins: {rs:12, rw:11, e:10, data:[5, 4, 3, 2]}
});
lcd.begin(16, 2);
lcd.print("Hello Internet.");

In options, the "pins" field can either be an array matching a call to any of the LiquidCrystal constructors or an object with "rs", "rw" (optional), "e" and a 4- or 8-long array of "data" pins. Pins will default to [12, 11, 5, 4, 3, 2] if not provided.

###lcd.begin(), lcd.clear(), lcd.home(), lcd.setCursor(), lcd.scrollDisplayLeft(), lcd.scrollDisplayRight()

These should behave the same as their counterparts in the LiquidCrystal library.

###lcd.display(on), lcd.cursor(on), lcd.blink(on), lcd.autoscroll(on)

These are similar to the methods in the LiquidCrystal library, however they can take an optional boolean parameter. If true or not provided, the setting is enabled. If false, the setting is disabled. For compatibility .noDisplay(), .noCursor(), .noBlink() and .noAutoscroll() methods are provided as well.

###lcd.write(val), lcd.print(val)

These take a buffer, string or integer and send it to the display. The .write and print methods are equivalent, aliases to the same function.

###lcd.createChar(location, charmap)

Configures a custom character for code location (numbers 0–7). charmap can be a 40-byte buffer as in the C++ method, or an array of 5-bit binary strings, or a 40-character string with pixels denoted by any non-space (' ') character. These bits determine the 5x8 pixel pattern of the custom character.

var square = new Buffer("1f1f1f1f1f1f1f1f", 'hex');

var smiley = [
  '00000',
  '10001',
  '00000',
  '00000',
  '10001',
  '01110',
  '00000'
];

var random =
  ".  .." +
  " . . " +
  ". . ." +
  " . . " +
  " ..  " +
  ".  . " +
  " .  ." +
  ".. .." ;

lcd.createChar(0, square);
lcd.createChar(1, smiley);
lcd.createChar(2, random);
lcd.setCursor(5,2);
lcd.print(new Buffer("\0\1\2\1\0"));    // NOTE: when `.print`ing a string, 'ascii' turns \0 into a space

##piezo

var led = new arduino.Piezo({
  board: board,
  pin: 13
});

Pin will default to 13.

###piezo.note(note, duration)

Play a pre-calculated note for a given duration (in milliseconds).

note must be a string, one of d, e, f, g, a, b, or c (must be lowercase)

###piezo.tone(tone, duration)

Write a square wave to the piezo element.

tone and duration must be integers. See code comments for math on tone generation.

##button

var button = new arduino.Button({
  board: board,
  pin: 13
});

Pin will default to 13.

Buttons are simply EventEmitters. They will emit the events up and down. You may also access their down property.

button.on('down', function(){
  // delete the database!
  console.log('BOOM');
});

setInterval(function(){
  console.log(button.down);
}, 1000);

##ping

See: http://arduino.cc/en/Tutorial/Ping

var range = new arduino.Ping({
  board: board
});

range.on('read', function () {
  console.log("Distance to target (cm)", range.centimeters);
});

##servo

var servo = new arduino.Servo({
  board: board
});

servo.write(0);
servo.write(180);

Pin will default to 9. (Arduino PWM default)

###servo.sweep()

Increment position from 0 to 180.

###servo.write(pos)

Instruct the servo to immediately go to a position from 0 to 180.

##motor

##potentiometer

protocol

Each message sent to the Arduino board by the board class has 8 bytes.

A full message looks like this:

!0113001.

! Start 01 Command (digitalWrite) 13 Pin number 001 Value (high) . Stop

I was drunk. It works.

##command

What is implemented right now:

• 00 pinMode
• 01 digitalWrite
• 02 digitalRead
• 03 analogWrite
• 04 analogRead
• 97 ping
• 98 servo
• 99 debug

##pin

Pins can be sent as an integer or a string(1, 2, "3", "A0")

##value

• board.LOW(0)
• board.HIGH(255)
• integer/string from 0-255 for PWM pins

license

(The MIT License)

Copyright (c) 2011 Cam Pedersen cam@onswipe.com

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the 'Software'), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED 'AS IS', WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.